FRONT VIEW OF THE BRISTOL THESEUS GAS -TURBINE (See page …

FRONT VIEW OF THE BRISTOL THESEUS GAS -TURBINE (See page 116)

FROM the world-famous Terry factory

come steel clips, bronzeclips, stainless clips, big

clips, little clips, wide clips,narrow clips - in fact clips in

every conceivable shape and size.Illustrated here are two of our stock

patterns, 8o and 81, made in a rangeof sizes to grip from 4 in. to z 2 in.

Maybe a clip of special shape would benecessary for the job you have in mind.

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LONDON MANCHESTER BIRMINGHAM

cupsby TERRY PRIMO

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f.C.4

January, 1947 NEWNES PRACTICAL MECHANICS_

109

SOME NEW BASSETT-LOWKEMODELS

SEND NOW for the Bassett-LowkeGauge ' O' Catalogue featuring some of

SEND NO W the pre-war range of famous models nowin production, together with permanentway and railway accessories . . . fully

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WRITE ALSO FOR" How to Build a Traction Engine " ... price 6d." Laying Permanent Way " 4d." How to Build a Gauge ' 0 ' Steam Mogul from a set

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Stock Lists of Sundries now available (LI12) 4d.Model Railway Handbook " Standard Edition fully Illustrated "

Price 5 Post 4d.

BASSETT-LOWKE LTD.NORTHAMPTON

LONDON: 112. High Holborn, W.C.I. MANCHESTER: 28, Corporation St. 4.

S. TYZACK & SON LTD.,ENGINEERS' MACHINERY AND TOOL SPECIALISTS

British Made Geared Scroll sell centring 3 -jaw Lathe chucks.High grade nickel chrome steel scrolls, alloy steel pinions,complete with two sets of jaws (internal and external).

4in. diam. 82,6. 6in. diam. 101;6. diam.

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RepairWITHTHE

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AN OFFER OPEN TO ALL READERSIf you arc interested in taking photographs or have ever thought of taking upphotography as a hobby you should send THREEPENCE IN STAMPS and ask for acopy of the newly published thirty-eight page book called " HOME PHOTOGRAPHY."It has been written by David Charles F.R.P.S., and it tells in a very simple andeasy -to -follow way how you can develop films, make prints and enlargements, andhow you can take portraits at home by artificial light. Do not miss this book.

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110 NEWNES PRACTICAL MECHANICS January, 1947

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ICS

THE " FLUXITE OWNS "AT WORK

Don't get the wind up, you four,Just give me a chance to explore.

It's a job for FLUXITE,There's a leak to put right,

And it's somewhere under this

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With Fluxite joints can be "wiped"successfully that are impossible

by any other methodUsed for over 30 years in Government works and by leadingengineers and manufacturers. Of all Ironmongers-in tins,10d., 1/6 and 3/-. Ask to see the FLUXITE POCKET BLOWLAMP, price 2/6d.Ai TO CYCLISTS ! Your wheels willW NOT keep round and true unless thespokes are tied with fine wire at the crossingsAND SOLDERED. This makes a muchstronger wheel. It's simple-with FLUXITE

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FLUXITEIT SIMPLIFIES ALL SOLDERING

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Alan en " WIPED JOINTS." Price Id. Each.FLUXITE LTD., Dept. P.M., Bermondsey Street, S.E.I

NEW UNIVERSALSPRAY GUN

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THE DOMESTIC SUPPLY CO.341, REGENT'S PARK ROAD,

LONDON, N.3.

January, 1947 NEWNES PRACTICAL MECHANICS 111

Price

23/6Every "Leytool " isa genuine post-wardesign, as acceptedby the Council ofIndustrial Design fordisplay at the" Britain Can MakeIt" Exhibition.momotemmis.

PRECISION

HANDDRILL

Prov. Potent No.20987144

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As illustrated. 4 -inch dia-meter capacity.

RATCHET SPANNERS42 Stock sizes. Indis-pensable for assembly andservicing work.SPECIAL : MOTORISTS'SETS of Ratchet Spannerscomplete in wallet.

UNIVERSALLY JOINTEDSOCKET SPANNERS

18 Stcck sizes.

POCKET SCREWDRIVERS4 -bladed.

" Leytools " are obtainablefrom all good Toolshops,Ironmongers and Stores. Ifany difficulty in obtaininglocally, send your orderdirect, or write for descriptiveleaflets giving full details ofsizes and prices of any ofthe above tools.

FURTHER "LEYTOOLS " ARENOW BEING DEVELOPED

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ACOrn 5021

V' (0 11 I MHEAVY DUTY BENCH LATHE

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New Large SizeThe most economicalway in which to buyErsin Multicore - thesolder wire containing3 cores of non -corro-sive Ersin Flux-is inthe new large Size OneCarton. Available in4 specifications. Wirepulls out withoutbecoming tangled.

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Price 6d.

SIZE ONE CARTONService Engineer and Maintenance Size

Cat.Ref. No.

AlloyTin Lead S .W .G

' ' '

Approx.lengthen--per carton

Lisf priceper carton(subject)

s. d.C16014 60/40 14 56 feet 6 0

C16018 60/40 18 151 feet 6 9

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This space is donated to WUWU by S. Wolf & Co. Ltd., Pioneer Works:Hanger Lane, London, W.5, Manufacturers of Wolf ELECTRIC TOOLS'

comprising Drills, Bench, Pedestal and Hand Grinders, Sanders,

Hammers, Screwdrivers, Blowers, Engine Reconditioning Equipment. Etc.


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" WESTON " Moving Coil Meters, edgetype. 21in. scale, 0 to .3 amps, 30/- ; 0 to 2amps., 2716 ; 0 to 60 volts, 2716 ; 0 to 150volts, 2716, all have F.S.D. of 2 mlamps.0 to I volt, I mla. F.S.D., 351- ; another31in. scale reading decibels 50 microamos.,F.S.D., 701-, another 301 model 0 to 3 mla.,401- ; 0 to 50 mla., 35/- ; 0 to 200 mla., 351,ELECTRIC LIGHT CHECK -METERS,guaranteed electrically, 200 250 volts 50 cy.,I phase. input 5 amp. type, 1216 ; 10 amp.type, 151- each. Carriage II-.ERNEST TURNER, moving coil mlamp.meters 2in. scale, 0 to 10 nth., 0 to 20mla., 0 to 50 mla., 2716 each ; all fullyguaranteed. Standard Telephone 3in, scalemkoil meters, calibrated to read 0 to 25,100 volts movement, I mla., incorporatingmetal rectifier, 451- each.EX.-G.P.O. MAGNETO GENERA-TORS, hand -driven, approx. output 75volts 20 mlamps. A.C., useful to theexperimenter, small pattern, 716 each.USEFUL PANELS made by StandardTelephone for the R.A.F., size approx.I9in. x 8in. x Sin, consisting of condenserscalibrated to decibels, chokes, mod. xformers, resistances and many other usefulcomponents, condition new, 1216 each,post 216.VOLTAGE CHANGER TRANS-FORMERS. Auto -wound, fully guaran-teed, immediate delivery. 350 watts, 551-500 watts, 701- ; 1,000 watts, £5 I 5s. ; 2,000watts, £9 15s. All tapped 0, 110, 200, 220and 240 volts.TRANSFORMERS BY WELL-KNOWN MAKERS, input 200 250 volts50 cy. 1 phase output 1,500 volts at 3kilowatts twice, £12 10s. each. VoltageRegulation Transformer oil type 2001250volts 50 cy. I phase, £15 each, new condition.MAINS TRANSFORMERS, all bywell-known makers and fully guaranteed,input 200 250 volts, 50 cy. 1 phase ; output2,0000.2,000 volts at 250 mlamps. with2 L.T. tappings, 75/-. Ditto, 475 0 475 voltsat 150 mlamps., with 3 L.T. tappings, 4vand 6v., price 4216. Ditto, 80, 100, 120, 140,200, 220, 240 volts at 3,000 watts, £12 10s.Ditto, 6, 16 volts at 14 90 amps. output,£15. Transformer cores, suitable for winding2,000 watts, 2716 ; 100 watts, 716 each.EX.-R.A.F. 10 -VALVE CHASSIS (soldfor components only). Consisting of : 2.150 ohm Mult. Contact Relays, 9 Britishtype Octal Base Valve Holders, 30 TubularCondensers, ranging from 10 P.F. to 1 M.F.25 30 Resistances 1, , 1 and 2 watts allmounted on chassis, size I2in. x 8in. x 2in.Components all in good condition. " A realbargain " at 1216 each, postage 116.EX -GOVT. ROTARY CONVERTERS,input 12 to 18 volts D.C. at 31 amps. output.450 volts 60 mlamps. fitted with automaticswitching and smoothing, 3216 each. 216

carriage.BALLAST LAMPS (GOOD MAKERS),new 125 volt 30 watts E.S. fitting, 61- perdozen.EX-G.P.O. PRE-UNISELECTORS, 3

ohm automatic relay operating a 4 -wayYaxley switch, fitted with 2 condensers.01, 1) M.F., new, boxed, 51- each. G.P.O.Polarised Telegraph Sounders in newcondition, 151- each. G.P.O. PolarisedRelays. operating on 10.20 mlamps. coil"esistance, 230 ohms, 151- each, as new.SHORT WAVE H.F. CHOKES, 116 ;

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xmitter rack. Size : 40in. x 24in. x I6in.,30I-. Ditto, 58in. x I9in. x I2in., 501-.Ditto, 58in. x 33in. x I8in., 701, Carriage716 on all types.LARGE TYPE RECTIFIERS" METAL."Outputs 12 volts 4 amps., 4216. 12 volts6S amps., 551- : 50 volts 2 amps., 4216 ;

12 volts 2 amps., 3216. " Mains Trans-formers " Tapped input 200250 volts 6,12, 24 volts 6 8 amps. ouput to suit theanode. 12 volt Rectifiers, 401- each. 21 -

carriage. Transformer to suit the 50 volttype, 4216. Carriage 216.

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114 NEWNES PRACTICAL MECHANICS January, 19 47

PREPARE FOR COMPETITION -NOW!As the Engineering Industry swings into its peace -time stride, the inevitable competitionfor the secure and well -paid posts will return. It is the man who stands out from therest because he is technically trained who will be in the happy position of taking overthe more responsible, more secure, and better paid positions. " ENGINEERINGOPPORTUNITIES " will show you how to get this all-important technical trainingquickly and easily in your spare time. This 100 -page book is full of valuable informationand explains the simplest way of preparing for recognised Examinations. Among thecourses described are :

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THE B.I.E.T. IS THE LEADING INSTITUTE OF ITS KIND. IN THE WORLD


InlandAbroadCanada

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Telegrams : Newnes, Rand, London.Registered at the G.P.O. for transmission by

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Copyright in all drawings, photographs and anklespublished in " Practical Mechanics " is speciallyreserved throughout the countries signatory to theBerne Convention and the U.S.A. Reproductionsor imitations of any of these are therefore

expressly forbidden.

FAIR COMMENT

PRACTICALMECHANICS

Owing to the paper shortage "The Cyclist," "Practical Motorist," and "Home Movies" aretemporarily incorporated.

Editor: F. J. CAMM

. VOL. XIV JANUARY, 1947 No. 160

Electro-platingMA ANY of our readers are addressing

queries to us concerning the possi-bility of doing plating on a small

scale at home. Electro-plating is one of thebottlenecks of industry at the present time.There is a great shortage of plant, of skilledplaters, and of plating solutions and materials.

Readers contemplating the installation ofelectro-plating plant may not be taware thatsuppliers can only supply dangerous poisonssuch as are used in electro-plating to officialorders. The use of chromium solution isstrictly controlled on account of its greatdestructive powers. It can only be used in aproperly constructed and equipped vat withan efficient fume exhaust apparatus as requiredby the Homo Office.

The process is quite unsuitable for amateurswho wish to operate it in an ordinary house,and those who have only a few articles toplate are advised to send them to a tradeplater. It will he cheaper and more satis-factory. Very few readers could insta'l thehigh-speed polishing spindles necessary tosecure a finish after the metal has beendeposited. Such apparatus is costly and it isonly economical to install it when largenumbers of parts are to be plated.

Sound RecordingSIMILARLY, many readers are interested

in sound recording, particularly by thewire or tape method. We shall shortlycommence publication of a series of articleson this subject which cannot be discussedin the course of a letter. Here again there isa great shortage of materials, and very fewreaders we think would be able to constructa successful tape recorder. Methods suitablefor amateurs will be fully dealt with in ourarticles. In the meantime, readers are advisedto get into touch with the British SoundRecording Association, BCM/BSRA, London,W.C.i. This Association 'was formed in1936 by a group of electro-acoustic engineersand amateur technicians with the specialpurpose of uniting in one organisation allthose professionals and amateurs in GreatBritain engaged or interested in soundrecording.

The main objects of the Association arefor members to meet for discussion on allaspects of sound recording and reproductionby known methods ; to conduct experimentsand research ; to hold lectures, demonstra-tions and exhibitions; to visit places of interest;and mutually to assist members by the inter-change of ideas and experiences and bycollecting and disseminating technical andother information.

The information bureau of the Associationoffers advice on any problem relating to soundrecording. Details of the latest equipmentavailable, authoritative articles, references to

current recording literature of the world, andcontact with fellow members, are providedfree.

There is a widespread and increasinginterest in sound recording, and membershipof this Association will prove valuable tothose whose interests lie in that direction. '

Age Limitations in EngineeringAT recent meetings of the Civil, Mechanical

and Electrical Engineering AdvisoryCommittee to the Technical and ScientificRegister, special consideration was given tothe difficulties experienced in meeting therequirements of employers by reason of thesomewhat rigid age limitations which areoften imposed.

Many vacancies essential to the reconstruc-tion programme remain unfilled because ofthe shortage of qualified engineers in theyounger age groups, though older menbetween the ages of 45-60 are available. Anumber of these volunteered for service in theTechnical Branches of the Armed Forces, orwere called up as Territorials. Some haveseen service in two wars.

In view of the declared shortage of qualifiedengineers the Committee felt that it wasuneconomical for the services of these capablemen-many of them excellent material andwith good administrative experience-notto be utilised to the full. They appeal toengineering employers who are willing tointerview such men with a view to offeringthem, if suitable, reasonable opportunitiesof employment-either permanent or tem-porary-to communicate with the Ministry ofLabour and National Service, Technicaland Scientific Register, York House, Kingsway,W.C.2 (Telephone Temple Bar 8020).

Facilities are provided at that address foremployers to discuss with the TechnicalOfficers of the Register the prospects offinding suitable candidates for their vacancies,and to examine in person the registrationparticulars of men and women who 'areseeking technical or scientific employment ofprofessional standard. Where desired,arrangements can also be made for employersto interview selected candidates at the officesof the Register.

Business TrainingAT fifty technical and commercial colleges

in Britain, 1,814 young men and women,whose chances for a business career wereprevented or interrupted by war service, aretaking the three months' General BusinessCourse of the Ministry of Labour's BusinessTraining Scheme.

Since the start of the Business TrainingScheme in April of last year, some 1,158students in centres up and down the countryhave successfully completed the GeneralBusiness Course, which marks the first step

BY THE EDITOR

in their training for management in commerceor industry. Most of these students havenow been placed in Specialised BusinessCourses approved by the Ministry andorganised and conducted by individual firmsto give intensive full-length training in thetype of business in which the student wantsto make his career.

Specialised CoursesThe Specialised Courses may last from

six months to two years, depending on thenature of the business, and in both Generaland Specialised Courses the Business TrainingScheme provides for financial help where it isneeded during the whole period of training.

The response of employers in acceptingstudents for specialised training within theirfirms has been on the whole encouraging.To date, 792 Specialised Courses have beenarranged, providing 1,670 training places.

So far, the biggest response in the driveto arrange Specialised Courses has come fromthe field of engineering. Engineering firmshave provided the largest number of courses,far more than in any other branch of business.

But firms of very widely different businessinterests have set up Specialised Courses.They vary from the largest industrial concernto the small family merchant employing lessthan a hundred staff. Frequently the smallor medium-sized concern has been able totake a relatively large number of trainees inproportion to its size, and this is particularlytrue of the type of firm needing young menof high quality and initiative to train inreadiness for a forthcoming expansion oftheir business.

Appeal to IndustryThere are still many firms who do not

know about the nature and advantages of thisBusiness Training Scheme. This is theprincipal obstacle in the way of arrangingSpecialised Courses, and it is found that themost effective way to overcome it is bypersonal contact. The staff of the Ministryhave already made some 5,000 personal callsin this way.

Students who have passed out from thethree months' General Business Course takeup their specialised training with a firmafter being selected at an interview with theemployer. Recent experience has shownthat some employers are finding it difficultto judge these men on their potential quality.They are inclined to be more intent onfinding out a man's background, which inmost cases is only slightly, if at all, relevantto business, or they compare this man withothers of a similar age who have spent yearsin business.

A similar problem faced the Ministry inselecting ex -Service candidates for admissionto the Scheme.


The Bristol "TheseusPropeller Turbine EnAine

COMPRESSOR SHAFT

AXIAL COMPRESSOR CENTRIFUGALIMPELLER

AUXILIARY GEAR CASING

AIR INTAKE

REDUCTION GEAR-

PROPELLER SHAFT

err

STARTER MOTORMOUNTING FACE

OIL PUMP DRIVE

OIL SUMP

PROPELLER TURBINE WHEEL

General Description, Technical Details and Operating Notes

MOUNTING BEAM COMPRESSOR TURBINE WHEEL

TURBINE MOUNTING

PROPELLER TURBINE SHAFT DIFFUSER COMBUSTION CHAMBER

Sectional view of the Bristol " Theseus" gas turbine.

THE Bristol Aeroplane Company hasalways been in the forefront of newdevelopments and the engine division

has for many years past taken a keen interestin gas turbines and their associated problems,it being understood that in due course,metallurgical developments would enablethem to be developed as suitable powerplants for aircraft.

As far back as 1923 a Bristol Jupiterengine was adapted to incorporate an exhaustdriven turbo -supercharger and several success-ful flights were made with this arrangement,but the supercharger was ahead of enginedevelopment and the work was thereforediscontinued. General investigation did notstop, however, and the good results cif thesleeve valve engine in 1937 and 1938 stimulatedthe design, manufacture and testing ofanother exhaust -driven turbo -supercharger.

Initial testing was cut short by the outbreakof the war, but theoretical work was continuedand investigations into the possibilities of apiston engine and gas turbine combinationwere made. These studies were given anadditional impetus by Air Commodore F.Whittle's success in jet propulsion work.

High Thermal EfficiencyThe Bristol Aeroplane Company felt that

since their experience lay chiefly in installa-tions for large and long-range aircraft, anyform of gas turbine which might be con-sidered should be designed with such applica-tion in mind. As a result the general policyof concentrating on units of high thermalefficiency was formulated. It was understoodthat this general policy would necessitatethe design of units suitable for aircraft ofmoderate cruising speeds, namely, 300 m.p.h.,

increasing in about five years or so to 400m.p.h. At these speeds the propulsiveefficiency of the pure jet is low and accordinglydesign work has been concentrated primarilyon propeller turbine engines, since , it isgenerally recognised that the propeller is themost efficient means of propulsion for speedsup to approximately 500 m.p.h.

The primary target aimed at, therefore,was the design of a propeller turbine having afuel consumption comparable to that of apiston engine at 30o m.p.h. and 2o,o0oft.These conditions were chosen as beingthe most arduous for efficient operation of agas turbine, since at higher speeds andaltitudes, the efficiency of the gas turbine isincreased.

Of the various methods of obtaining a highthermal efficiency from a gas turbine, the ideaof utilising the waste heat of the exhaustgases looked very promising, and so a heatexchanger was designed to transfer thisheat to the compressor delivery air at apoint ahead of the combustion chambers.The adoption of the heat exchanger permittedthe use of well established compressionratios and operating temperatures.

Design work along the lines describedabove has resulted in the manufacture of theTheseus propeller turbine engine, which hasnow completed several hundreds of hours ofbench testing, including a too hours' endurancerun at operating conditions with mostsatisfactory results.

Initial flight testing of the Theseus willbe carried out on an Avro Lincoln aircrafthaving the two outboard reciprocating plantsreplaced by Theseus propeller turbines.

The successful development of the Theseus

HEAT EXCHANGER

TRANSFER PIPE ENGINE MOUNTING

has caused great interest among aircraftconstructors and Messrs. Handley Page,Limited, have already announced theirintention to install this engine in a prototypeHermes aircraft.

Heat Exchanger Propeller TurbineThe Bristol Theseus unit is designed

primarily as a power plant suitable forlong-range aircraft. The fundamental featuresof such power plants are as follows :

(a) Low fuel consumption.(b) Long periods between overhauls.(c) Adequate thrust for take -off.(d) Efficiency of propulsion over a wide

range.To achieve these ends with the Bristol gas

turbine the following salient design featureswere included. A heat exchanger has beenincorporated to recuperate some of the heatthat would normally be wasted in the jet,thereby greatly improving fuel consumption.To give adequate take -off thrust and efficientpropulsion at moderate aircraft speeds, apropeller driven from a separate turbine stageis fitted. Longevity of engine has beenaccomplished by limiting the stresses, boththermal and tensile, of the rotating parts tosafe values. The combination of the abovefeatures results in a unit that is capable ofcontinuous operation at its full designedpower for long periods without distress andthereby operating at the turbine's mosteconomic condition.

Power PlantsBriefly, the " Bristol " Theseus I gas

turbine consists of an axial flow compressorcombined with a centrifugal stage and drivenby a two -stage turbine. The air after passing

January, 19 47 NEWNES PRACTICAL MECHANICS 117

through this compressor is delivered to aheat exchanger which raises its temperatureby heat transfer from the hot exhaust gases.The air then passes through the combustionchambers to the first two -stage turbine,where part of the energy of the charge is usedto drive the compressor. After this the gasespass through the third single -stage turbine(where power is absorbed to provide the driveto the propeller) arid then pass through thehot side of the heat exchanger. Theirresidual energy is finally dissipated in theexhaust nozzle to provide an appreciableamount of jet thrust. The main proportionof available power is transmitted from thethird stage turbine to a conventional tractorpropeller via an epicyclic reduction gear.

The ratio of power used in driving thepropeller to that used in providing jet thrustis roughly in the proportion of 8o per cent.to 20 per cent. at 30o m.p.h.

AssembliesIn dealing with the main assemblies of the

Theseus I gas turbine it is convenient tofollow the passage of the air through the unitand to describe each section in that order.We therefore have the following headings:

Compressor AssemblyThe air enters the compressor via a forward

facing, annular intake, situated around theperiphery of the reduction gear and justbehind the propeller. The compressor itselfconsists of nine stages or axial, bladingcombined with a single -stage centrifugal

Compressor turbine wheel, showingthe double row of blades.

impeller giving an overall compression ratioof approximately 5 : i when flying at 300m.p.h. and 2o,000ft.

The particular combination of axial andcentrifugal compressors was chosen for twomain reasons. In the first place the use of acentrifugal impeller as the last stage providesan efficient means of getting the air from thesmaller diameter of the axial compressor tothe larger diameter required by the heatexchanger. Secondly, it is well known thatalthough the axial compressor can be madeto operate more efficiently at higher compres-sion ratios than the centrifugal type, thelatter has a wider operating range, and so thecombination of the two produces a com-pressor having a high overall efficiency alliedwith greater flexibility. Mechanically theconstruction is as follows.

Intake CasingThis is an aluminium alloy casting

consisting of an inner and outer shell,connected to each other by means of eightradial and hollow vanes of aerofoil section.The whole of the intake casing is cast in oneand provision is made for the attachmentof the starter motor on the horizontal -centreline as well as for an oil sump at the bottom.The inner shell accommodates the reductiongear and auxiliary gear casing, drives beingled through the hollow vases to the starterand oil sump.

Compressor CasingThe main compressor casing is also made

of aluminium alloy and is cast in two halves.The axial section and part of the centrifugalone is of double skin construction in orderto relieve that portion of the compressorcarrying the stator blades of stresses due topropeller loads. The rear portion ofthis casing forms the front face of thecentrifugal impeller chamber and to-gether with the delivery manifold andrear casing forms the centrifugal stageof the compressor. Blow -off valves areincorporated for starting purposes.

One half of the compressor casing.

Delivery Manifold, Vane Ring and RearCasingThe delivery manifold collects the com-

pressed air from the impeller after suitablediffusion through the vane ring and passes itto the cold side of the heat exchanger througheight transfer pipes. It is a one-piecemagnesium casting, in contrast to the diffuservane ring which is cast in two halves (alsoof magnesium).

The rear casing is an aluminium castingwhich forms the back face of the centrifugalimpeller chamber and is extended backwardsto carry the main compressor thrust bearing.It is joined to the compressor casing by meansof long bolts running through the diffuservanes.

Axial Compressor RotorThis is of drum construction, being made

of a high-grade aluminium alloy forging. Thedrum is made up out of three identicalsections for ease of manufacture and assemblyand is supported by two conical steel shaftsbolted to the drum and carried in a frontroller bearing and a rear ball bearing whichalso supports the compressor turbine wheel.

The rotor blades, as in the case of thestator blades, are made from high gradealuminium alloy stampings and are fixed tothe rotor drum by means of serrated slotsrunning axially. There are nine stages, eachof which contains 69 blades.

ImpellerThis follows the usual Bristol practice in

that it is machined from a solid aluminiumforging and is bolted on to the axial rotordrum to form the final stage of compression.The impeller has 23 straight radial vanesand is double shrouded.

...

' One third of the compressor rotordrum.

Propeller turbine wheel and shaft. The combustion chamber.


The compressor runs at 8,200 r.p.m. at fullthrottle conditions and delivers 3o lbs./sec.of air at sea level static conditions. Thepower required to drive this is approximately3,5oo h.p.

Every attempt has been made in thedesign to provide a simple and robust con-struction which results in a low stressed butlight assembly.

Heat ExchangersFollowing the passage of the air through

the unit, the next assembly to be dealt withis the heat exchanger. The air is deliveredfrom the compressor discharge manifold tothe heat exchanger by means of eightaluminium diffusing transfer ducts spacedequally around the periphery of the engine.

The heat exchanger is of a matrix type

TurbinesThe products of combustion are delivered

to the first stage nozzles through a tangentialdelivery manifold. These nozzles, of whichthere are 48, direct the gases on to the firststage rotor blades, after which the gases arere -directed on to the second stage rotorblades by the second stage stators. Boththese first two stages of rotor blades arefixed to the same wheel disc and the powergenerated is used to drive the compressorand auxiliaries only.

After leaving the compressor driving wheelthe gases pass through a third stage of statorblades to be guided on to a single stagerotor wheel, which is coupled to the propellerreduction gear. The propeller turbinerevolves at a speed of 9,000 r.p.m. The gasesare then led through a diffuser to the hotside of the heat exchanger, after which they

The compressor rotor assembly.

construction, consisting of some hundreds ofstraight tubes running parallel to the axialcentre line, thus offering the minimumresistance _to the passage of the hot exhaustgases which pass through them. The tubesare arranged in 1-6 sets, 8 inlet and 8 outlet,each batch being separated from the next bysuitable headers. The air passes radiallyinwards towards the centre of the heatexchanger, where its direction is reversed,and it travels radially outwards again to theoutlet headers. During its passage throughthe heat exchanger the air picks up heatfrom the hot exhaust gases and from theoutlet headers it is passed into the combustionchambers.

Combustion ChambersThe combustion chambers, which are

spaced between the transfer ducts around theperiphery of the engine, are of standarddesign and arc of sheet metal constructionthroughout. Provision is made for theadmission of secondary cooling air to theburning mixture in order that the temperaturemay be lowered to a value acceptable to theturbine blade materials.

The combustion chambers are inter-connectsx1 for even flame distribution andequalisation of pressure, and two of them areprovided with sparking plugs for initiatingcombustion during starting. Full provisionis made for accommodating any expansionswhich may occur.

1

are discharged from the jet pipe, which hasa variable nozzle.

The separation of the propeller and com-pressor turbines was decided upon after muchconsideration. It is obvious that withmechanically coupled turbines, the questionof relative speed control becomes verydifficult and renders the performance of theengine very critical. By separating the twodrives as has been done in the Theseus I, theoperation of the engine is simplified, and bymeans of a specially developed mechanism,the propeller pitch is automatically controlledso as to maintain a constant speed ratio inrelation to the compressor.

A further advantage of this separation isthat the starter motor has to rotate only thecompressor and not the propeller. Conse-quently a smaller starter motor can be used.

Turning to the mechanical design, thefollowing details may be described :

Turbine Casings. The turbine casing isformed from three separate castings madeof high grade heat -resisting steel, the thirdstage casing also providing a support for therear bearing of the propeller drive andturbine, by means of eight radial vanes,largely in the manner described for thecompressor intake casing.

Turbine Wheels. The compressor drivingwheel carries the first two stages of rotorblades and is of forged high temperatureresisting steel to Jessop's specification G. 18B.A hollow hub is forged integral with the

disc and is splined to transmit the drive tothe compressor shaft.

The propeller driving wheel is a Staybladeforging, carrying a single row of rotor bladesand having an integral forged stub shaft toprovide the support from the rear bearing.The extended driving shaft is bolted directlyto the disc and transmits the drive to theepicyclic reduction gear.

The turbine blades are fixed to the wheelsby means of fir tree type slots, obtained bybroaching.

Turbine Blades. The stator blades are madefrom precision castings in a special heat -resisting alloy. The rotor blades are forgedfrom the same material and are of the FreeVortex type.

Mounting. The turbine assembly is mountedseparately from the rest of the unit by meansof a secondary triangulated structure,supported from the main mounting face.This permits of the accommodation of anylongitudinal expansions, and in addition theturbine mounting provides for freedom ofexpansion in the radial direction, whilstmaintaining concentricity.

General. Provision is made for the coolingof the turbine wheels by means of tappingsfrom the axial compressor. A system oflabyrinths provides effective sealing betweenthe various stages of the turbine.

As in the compressor, the design has aimedat providing a simple and strong constructionwithout any undue sacrifice in weight. Thestresses are, therefore, of a low order andcare has been taken to avoid any high con-centration of both temperature and stress.Expansions have been well catered for andthe creep effects have been reduced to aminimum. The maximum gas temperatureat the entry to the turbine does not exceed800 deg. C.

Reduction GearHaving traced the path of the air circuit

in the unit it now remains to describe thoseassemblies which have no direct bearing onthe principles of functioning of the engine.

The reduction gear, as has been statedpreviously, is of the epicyclic type and isdriven from the propeller turbine wheel bymeans of a long shaft running through andcoaxial with the compressor assembly. Thisshaft is supported on a roller bearing at thefront and a ball thrust bearing at the rear.At the forward end the shaft drives through agear type coupling to the sun wheel of thereduction gear. The sun wheel drives thelarger gears of four sets of compound planetscarried in a cage bolted to the propellershaft. The action of the smaller planetwheels on a fixed annulus gear causes theplanet cage and hence the propeller shaft torotate at the speed required, which is approxi-mately 1,070 r.p.m., the reduction gear ratiobeing approximately 8.4 : 1. The fixed annulusgear is mounted on torque dynamometer pistonsand this provides the additional advantage ofequalising the tooth loads on all the planetwheels. A single row ball bearing is providedto carry the thrust of the propeller.

Auxiliary DrivesAn oil sump is provided underneath the

intake casing and incorporates drives to theoil pressure and scavenge pumps and afuel pump. The drive to these pumps istaken from the compressor rotor via bevel gearscontained in an auxiliary gear casing whichis in turn housed within the intake casing.

The auxiliary gear casing includes thedrive from the starter motor, situated on thehorizontal centre line of the intake casing.The starter motor drives through conven-tional type Bendix jaws to the compressorrotor. The device for controlling the propellerpitch change mechanism is also includedin this casing.

(To be concluded.)


TheDetails of a Small

RepublzcAmphibian 'Plane Built in the

Seabee11

United States By J. W. R. TAYLOR

Side view of a " Seabee" on the water. Here the prototype, with tapered wings, is shown.

AMERICA is notorious for doing thingsin a big way. So it is not surprisingthat, having made up their minds

that they ought to be air -minded, theAmerican public are now ordering family'planes by the thousand. Foremost targetof the potential aviators is the little RepublicSeabee amphibian, which is hardly surprising,as it seems to be everyone's dream of apost-war family 'plane come true. SoRepublic's huge Farmingdale plant, whichturned out 55,329 ten -ton Thunderboltsduring the war, has now been converted toproduce about 4o of the little one -and -a -halfton Seabees every day.

215 H.P FRANKLIN 6A8-215-BBF ENGINE

MOORING DOOR

All -metal ConstructionThink of all the features you'd like to find

in your own light 'plane, and ten to oneyou'll find most of them in the Seabee. For,although it is an all -metal four -seater with a255 h.p. engine, careful and economicaldesign has kept the initial cost down toabout £5,000. It is roomy, sturdy, easy tomaintain, has a good performance, cantake off and alight on land and water and,because of its low structural weight, iscomparatively economical to run.

The prototype Seabee looked very similarin general appearance to the models nowcoming off the production line, but under

AEROMASTER GROUND ADJUSTEDLAMINATED MAPLE PROPELLEk

that metal skin are revolutionary engineeringchanges that have reduced the number ofcomponent parts from 5,800 to 450, and thetime needed to build a Seabee from 2,500hours to zoo hours. In addition, the airframeweight has gone down from 5,26o1b. to5,54o1b., and, in spite of an increase in enginepower of 4o h.p., the price has been nearlyhalved, which, even in hard figures, isquite an achievement !' Republic's originally set out to design an

aircraft that would be as comfortable, easyto produce, maintain and handle as a car.Obviously, such a machine had to beindependent of large airfields, as the sort ofplace where Father likes to go fishing orwhere Junior goes camping is not usuallygraced by the presence of an aerodrome. Sothey decided on an amphibian which couldnot only take off from small, unpreparedfields but also from the lakes and rivers whichabound in America. They started off witha small cabin, rather like a car body, withample room for four people. Then theydecided to mount the Franklin engine to therear of the cabin, which ensured a good forwardview and reduced much of the usual noise andfumes. This necessitated cutting down thecross-sectional area of the rear fuselage toclear the propeller, until the Seabee lookedrather like a tadpole with a very large tail end.But this did not affect the structural strength,so everyone was happy. A high wingarrangement was an obvious choice, to carrythe wing well clear of the water and improvethe downward view from the cabin-also itsbracing struts prevented people barging outof the 'cabin and back into the propeller.Floats were added under the wings, togetherwith a retractable wheel each side of thecabin, and the result was the Seabee, whichfirst flew in November, 5944.

RIBBED SKIN FOR STIFFNESS

DOOR REMOVED TO SHOW INTERIOR MAIN WHEELS IN RETRACTED POSITION

Cut -away drawing of the Republic " Seabee," showing details of construction of fuselage and wings.

WATER RUDDER


Mass -production MethodsThis prototype was quite orthodox in

construction and was built chiefly to test thegeneral design. It would have sold at about£1,900 which, it was decided, was too much.So one of their engineers-Alfred Boyajian-and his staff were given the job of producing a

t,000 Seabee.The major expense in almost any job is,

of course, manpower, so it was largely aquestion of re -designing the aircraft formodern cheap mass -production methodsof manufacture. The fact that most impressedBoyajian was that aircraft structure haschanged very little in spite of the change -overfrom wood -and -fabric to metal construction.This seemed all wrong. Fabric cannotabsorb or pass on much stressing load, metalcovering can-so why should all the internalformers and ribs with fabric covering stillhave to be retained ? Anyway, he decidedto experiment with structures consisting of afew basic internal members reinforced by astiff metal skin covering. Applied to thehull, his theories reduced the number ofcomponent parts from 362 to 63, the resultbeing a sturdy monocoque structure to whichthe cabin is bolted. The latter shows veryclearly the influence of car industry productionmethods, and consists of simple large pressings,the interior furnishings, fittings .Indinstruments being for the large part standardcar components.

Wing and Tail SurfacesThe most revolutionary change was made

in the wing and tail surfaces, which aresimilar in construction. First of all, wingtaper was abolished to save production time,then -the whole structure was re -designed,dispensing with the stringers and all 'butthree of the ribs, and relying solely on threemain parallel -section spars and the skincovering for structural strength. The skinis ribbed externally for stiffness, and thisgives a corrugated effect rather like the oldJunkers designs. The result is a very sturdy

A " Seabee" moored by the side of a lake.

structure which, in the case of the wing, hasreduced the number of component parts from114 to 3o. The wing floats are each made ofjust two pressings and all the electrical wiringcan be installed in eleven minutes !

In no case has this simplification andeconomy been allowed to affect comfort,efficiency or reliability, and typical of theSeabee's comprehensive equipment is thefact that two-way radio is fitted as standard.The seats are adjustable and the front onesfold back for conversion into sleeping -bunks.In addition, the backs are detachable foruse as buoyant rafts in an emergency. The

fuel tank is of the " crash -proof " fabric -bagtype and is housed in a water tight com-partment in the hull.

The Seabee, which has a span of 37ft. 8ins.,and a length of 28ft., has a top speed of120 m.p.h. and cruises at 103 m.p.h. for56o miles with full load. It can take -off in800ft. from land or t,000ft from water,needing a draught of only 18ins. As aproduction job it can teach many valuablelessons to almost every aircraft designer inthe world. As a family 'plane it bringsnearer the day when flying will be cheapenough and safe enough for all.

Mathematics as a Pastime -1Square on the Hypotenuse. By W. J. WESTON -

yOU remember the curious Greek word," hypotenuse " : it means " stretching

across," and is applied to the line stretchingacross the right-angle of a right-angled triangle.You remember, too, this relation between thehypotenuse and the other two sides of thetriangle : the square on the hypotenuse isequal to the sum of the squares on the sidescontaining the right-angle. Thus, draw ahorizontal line 4in. long; at one end erect avertical line Sin. long ; you may be quitecertain that the line joining the other twoends of the line will be 5in. long (42+32 is16 +9, or 25, and 25 is 52).

Now, this truth is not self-evident. TheGreek mathematician who hit upon the proofsacrificed an ox to the gods in his elation.You, too, ask for assurance ; for, beingSensible, you don't take things for granted.Well, will you for your satisfaction anddelight, do this ?

Draw two identical squares (see diagram) ;4in. to each side will be ample. Cut everyside of the two squares into identical lengths-in one, long -short, long -short, long -short, long -short in the other, short -long, long-shOrt,long -short, short -long. Join the ends.

You have now, in each of the original

squares, four identical right-angled triangles.In the left square you have in addition asquare, H2, - and this is on the hypotenuseof the right-angled triangle. In the rightsquare the corresponding addition is R2 andA' together-and these are squares on thetwo sides containing the right-angle.

Diagrams used for squaringthe hypotenuse.

Whatever division you make of the sideAB, the truth emerges : the square on thehypotenuse is equal to the two squares on thesides containing the right-angle.

You will not always, or often, be able totranslate the sides into exact figures like our3, 4, 5. Another instance is 5 and 12 forthe sides containing the right-angle. For

52+122 iS 25 -j-144, or 169 ; and v's 69 is 13.Another instance is 8 and 15 for the sidescontaining the right-angle. For 82=152 is64 +225, or 289 ; and A/289 is 17.

Usually, however, the unknown side willbe an intractable surd ; and you will thenfind the square root to whatever degree ofaccuracy you think fit. Thus, the sidescontaining the right-angle being 5 and 4, thesquare on the hypotenuse is 25 +16, or 41 ;and the square root of this will be greater than6 but less than 7. How to tackle the problemof getting A/4I with ever-increasing degreesof accuracy is the theme of next month'sdiversion.

(To be continued.)

REFRESHER COURSEIN

MATHEMATICSBy F. J. CAMM.8/6, by post 9/-


; (Above) Prismatic glass for assem-bling the framework to form lensesfor lighthouses. The completedlens is for a lighthouse in the WestIndies. (Below) Final stages infitting the framework of a revolvinglighthouse lens prior to the inclu-sion of the prismatic glass rings.

British Lighthousesfor Export

New lighthouses and lighthouse equipment are badly needed all over the world and ordersare coming into Britain in great quantities. British lighthouse equipment is now beingmanufactured for Yugoslavia, Finland, Norway, China, India and Dutch East Indies.The ravages of the war years have made the complete replacement of many lighthouses anecessity. This series of photographs taken at Arlessrs. Chance Bros. of Smethwick,Birmingham, shows how the equipment is being made to execute the overseas orders.

Mechanism for rotating the lens which will be; assembled on the table shown, at a later date. ;

This apparatus is for Longstone Lighthouse, ofGrace Darling fame.

A typical lighthouse optic rotating on a; mercury bath by a clockwork mechanism, and

giving three consecutive short flashes followedby a single flash every 15 seconds.

(Above) The finishing process after the glass prisms have been focusedin the framework. This lens -panel is for the rotating optic of

the Longstone Lighthouse.(Left) Grinding a glass prism so that it may fit into the lens frame- I

work inside a lighthouse lantern.


epairinA Domestic ElectricalAppliances

Zocaz/24A-

loc..az /areIN these notes it is intended to deal with

more than the mere replacement of afuse or a burnt -out lamp. But first we

must deal with some " Don'ts."In this country, very soon, all supply will

be A.C. at about 240 volts. Now, the peakvoltage on A.C. is 240 multiplied by thesquare root of two, i.e, 240 x 1.414, orsomething over 33o. If you keep this pointin your mind's eye you will be more carefulabout taking shocks from the mains. Whenmaking an examination of any apparatus,always disconnect from the supply, either byremoving the plug or by switching off at themains. If you are doing any work on aninstallation, such as changing a fitting orplug, or anything connected with the per-manent wiring, then switch off at the mainsand pull the fuses. This is the only wayto make certain that someone will not comealong and switch on again.

The Main FuseWe will start with the point of entrance of

the cable and follow it to the various points,dealing with each fault as it arises. If amain fuse blows you cannot replace it, butmust 'phone the supply company, who willsend a man out to do it. The main fusebox is sealed, and it is an offence to breakthis. If a main goes, there must be someserious fault in the circuit.

Replacing Local FuseIf a local fuse blows, first find the reason

why. There is always a reason, and a verygood one. Generally, it is an overload onthe circuit, or some accidental short, wornflexes, or cut wires, and so on. Remedy this

and then replace the fuse with the correctsize. It is usual to employ 5 -amp. wire forlighting circuits, and so or 15 for power.Switch off the mains, remove the fuse carrier,clean off all carbon and fused wires, put inthe new wire, and replace. Switch on.Remember to remove all the old wire, andmake certain of good connections at the fuseclips. (See Fig. r.)

Fig. 4. -Details of aceiling rose,showingthe method

of fixing.

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Fig. t. Fuses andfuse carriers.

Useful Hints on the Upkeep andRepair of Domestic Electrical Appli-ances, and How to Avoid the ManyPitfalls That May be Encountered by

the Home ElectricianReplacing Switch

A switch may often need replacing, espe-cially in such places as garages and work-rooms, etc. First get a good switch of thesame type and pattern, i.e., 5- or ro-amp.,sunk or surface mounting. (See Figs. 2 and 3.)Switch off at the mains ; pull the fuses. Now

By " Home Mechanic"

slacken the connecting screws on the switch,remove the fixing screws, pull cut the switch,and then put in the new one. Take careto mount this the right way up and to putthe wires on the same sides as before. Itis quite possible to put the switch in sothat the knob is down and the light off.Don't throw away the old switch, it maybe kept as a useful spare in case of repairs.

Fig. 2. - Anefficient type of

switch.

The cover and terminals and the actionspring can be removed and put into brokenswitches. You may not think this worthwhile, but the repairing of a switch is quiteintricate and interesting work. To " openup " remove the sealing wax from the headsof the screws at the back ; undo these, andthe dolly will pull out. It may leave themovable contacts behind. If so, a slightpull will remove them, exposing the actionspring. You now have the switch in pieces,

Fig. 5.-Showing how ahousewife may obtain ashock froman unearth-

ed iron.

LIVE /RON

and it is easy if you have a spare to replaciea broken part. Contacts may be tightenedup by judicious pressure with the blade ofa screw -driver. Always use good switches.It should not be possible to hold the contacts,either just in or just out, so that arcingoccurs. The switch should open and closequickly with a snap, except in the case ofthe new silent switches for hospital work.Here the action is barely audible. (SeeFig. 3.)

The Distribution PointNow we come to the distribution point.

First the lamp -holder and flex. Flexes oftenget worn and frayed when the lamp swingsin a draught or when a portable appliance isused at that point. If you are doubtful of aflex, replace it-the cost is negligible. Inthe case of large and powerful lamps, theheat will cause the insulation to perish, andfinally the rubber cracks away, causing ashort, or the holder to become live. Never

Fig. 3. - Thistype of switchfits flush to the

wall.

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remove or replace a lamp with the switchon. In replacing a flex, switch off at themains and remove the fuses. Unscrew thecover of the ceiling rose, and disconnect theflex. Now, in a' more comfortable position,examine the holder. If the springs in thecontacts are quite good, it may be replacedon a new length of flex. Slip the rose coveron the flex, climb the ladder, and connectup. Make sure that the weight of the flexand fitting is taken by the little hooks orprojections on the rose base, and screw backthe cover. (See Fig. 4.)

A word on using portable appliances fromlight points and two -pin distribution points.The flex and holder are rated at 3 amps.You should not use anything taking morethan Soo watts from a holder. All portableapparatus should be earthed. It cannot beearthed if used from the ordinary holder.Yet, you may say, why are irons, fires andvacuum cleaners all sold with adaptors foruse on the light. This, of course, is to givethem a universal appeal, but the day is notfar off when all apparatus will be sold witha special plug of probably the three -pintype. The sketch shows how easy it isto get a shock from a two -pin point of,say, a fire or iron. The housewife is there,probably with damp hands, in the kitchen,ironing, in easy reach of gas and water taps


and earthed ironwork. A fault develops inthe iron. With one hand she touches thestove or a water tap, and a very bad shockresults. (See Fig. 5.) The same can happenwith open fires of the bowl type. Also, withtwo -pin plugs and fires with switches incor-porated, it is possible for the switches to beoff and the plug in and yet the element alive.If you wish to test all these statements, geta lamp, holder and flex with crocodile clipsas leads, and use this as your subject orpatient. Connect one lead to earth and theother to the iron or fire, as above, andobserve that the lamp will light. Whereverpossible use only lamps at the lamp -holdersand the proper apparatus at the two -pinpoint. These are designed for use withreading lamps and wireless sets, which,theoretically, may not require earthing.

The Power PointThis has an earth pin which must be

used. You may feel tempted to connect upthe iron to the plug with the original twinflex. Don't ; it is safer to get a good qualitytriple cable. If the iron is used a lot, thenwe advise a tough rubber covered cable.The extra safety will well repay the outlay.Braided cable has a nasty habit of frayingat the adaptor and then shorting. The wiresin the cable each have their own colour,so that it is an easy matter to earth thecorrect one. The latest iron adaptor hasa small spring tongue that touches the metalcase of the iron. This is the earth contact.Bend it out so that it makes good contact.The same general remarks apply here as

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regards frayed cables, etc , but one must usethe cable of the correct size for the appli-ance. If you are using a 3 -kilowatt firefrom a plug, don't wire up with lightingflex. Use the correct cable (this is generallysupplied with the appliance). On the otherhand, if you are using a 750 -watt fire froma 15 -amp. point, thinner- flex can be used,but to protect the circuit the Is -amp. fusemust be replaced with a 5 -amp. one. Thisis very important, because the earth mightbum before the fuse blows if a fault developsin the fire. Fig. 6 shows a socket from

POT

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Fig. 6.-A safe socket for all appliances.

which any apparatus may be used withsafety.

Two TypesAll domestic appliances can be divided

into two types-heating and motor driven.Special notes will be given for the varioustypes, but first a general survey of the heat-ing type. Here we include irons, fires,toasters, hair dryers, kettles, hot plates,stoves and cookers, because in each case theelement is a length of wire that gets hotwhen in use. A group of appliances is shownin Fig. 7. A combination of the two typesis found in modern fires and hair dryers,etc. Nowadays all heating elements arestandard, i.e., if your iron burns out a newelement can be bought from the makers.The sketches (Fig. 8) show a dismantlediron ; we will deal with fitting a new element

\z/li/C.4

CONNECTOR

ELEMENT

Repairing an Electric KettleA kettle element is very similar to that

of an iron, but is generally in two halves.The replacing of the element is carried outin the same way. First invert the kettle,then remove the cover plate exposing theelements. These are clamped under a thickcopper disc by one screw passing throughthe centre. Remove this and the elements.Connections are made through copper flexibles insulated with porcelain beads.Preserve these, as they must be put backon the new element. Observe the positionof the old element and replace the new onein exactly the same way. Connect up asbefore. Most kettles, sterilisers and similarappliances are fitted with a cut-out of somesort that opens the circuit when the vesselboils dry. Some have a small fusible capsulewhich has to be replaced each time it boilsdry. The commonest method, which isfound on all good -class apparatus, is thebi-metal thermostat. The actual design isthe same. A bi-metal strip forms part ofthe circuit, and when this is overheated itbends outwards and opens the circuit. Any

Fig. 8.-Anexplodedview of anelectric ironand below-

-the complete iron, mica elementand parts of an electric kettle.

first. Remove the cable connector. Theshell is fixed to the base by two fancy nuts,A and B. Unscrew these and gently liftthe cover off. In some types connectionis made by two springs from the adaptorto the element ; in others it is a strip ofmetal. If by springs, the cover comesstraight off ; if by strips, unscrew these atthe connector. The element is clamped tothe base between a heavy iron stop. Removethe two nuts and lift off the iron ; theelement may now be removed. The elementis wound of strip on a mica former

and is completely insulatedfrom the frame. Whenremoved, take it to your test-ing bench and connect inseries with a lamp. If itlights then the element isO.K. and the connector mustbe to blame. A faultyelement can generally bespotted by holding to thelight ; the burnt spot showsas a black dot. Don't attemptto repair an element, but putin a new one, lay flat on theplate, put on the iron weightand tighten up the nuts. Put

= on the cover, make sure thatthe springs touch the elementcorrectly, and warm up theiron. When hot, dismantleand put another half turn onthe clamping nuts.

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Fig. 7.-A group of "heater" appliances.

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repairs here consist in cleaning the contacts,and perhaps bending the strip slightly sothat a good contact is made. The contactscan be reset by a knob on the base of thekettle, and need not be touched in theordinary way.

SterilisersIn hospitals small sterilisers are very

common and are in constant use. These arefitted with robust overload relays generallyincorporating a mercury switch. Throughover -use the contact spring goes and oftenneeds replacing ; minor adjustments to con-tacts and strip are often required as well.

(To be concluded next month)

WORKSHOP CALCULATIONSTABLES AND FORMULA

Eighth Editionby F. J. CAMM

A handbook dealing with methods ofcalculation, solution to workshop problems,and the rules and formula: necessary invarious workshop processes. It containsall the information a mechanic normally

requires.From all booksellers, 6/- net,by post 6'6 from the publisher,

GEORGE NEWNES, LTD. (Book Dept.),Tower House, Southampton Street, W.C.2.


Notes and News" Deep " PhotographsQTUDIO portraits in which the details" stand out in three dimensions are likelyto be available -in this country shortly. Aprocess for producing these solid picturesquickly and cheaply is to be operated by aLondon firm.

The new process was invented by Maurice

to Argentina, while over 15o of the samevehicles are destined for Uruguay. Over8o single deck passenger chassis have beenordered for operation by various companiesin Denmark, and recently the British -ownedLisbon Tramways Company ordered 68single deck buses. Australia, South Africaand New Zealand are taking large numbers

The Wright airplane, first airplane to fly and one of the favourite exhibits at the Science Museum,South Kensington, London. The Science Museum has been told by Mr. Orville Wright, sur-viving brother of the famous Wright brothers, that it is his intention to withdraw it. The airplanewas originally loaned to the London museum as a protest against the American failure to recognise

it as the first 'plane to fly.

Bonnet, a 39 -year -old Frenchman. A specialcamera moving in an arc takes a series ofphotographs of the sitter. Lighting is normal,and mirrors play no part in the process.The negatives of these photographs aresuperimprosed between two glass plates by asecret method. The result, seen with thenaked eye, is a picture which looks like aglass box containing a solid sculptifre of thesitter. Minute details of form and clothingarc faithfully reproduced, and light reflectedfrom hair and jewels appears to scintillate.A three-dimensional photograph can betaken in about five minutes.

G.W.R. Gas Turbine Locomotive

AN order was recently placed by theG.W.R. with British Brown-Boveri,

Ltd., for a gas turbine locomotive. The enginewill develop an output of 2,50o h.p. and willbe capable of a maximum speed of 90 m.p.h.The locomotive will be used on expresspassenger services.

British Motor Vehicles for ExportSINCE the Associated Equipment Com-

pany, builders of London'S buses,resumed production Of civilian chaisis follow-ing the cessation of hostilities, a total ofover 1,600 has been ordered for overseasmarkets. This figure comprises machinesof every type-single and double -deck pas-senger vehicles and goods vehiclei rangingfrom 12 to 22 tons gross. One of the mostimportant orders received was from the IraqPetroleum Co., Ltd., for 66 special tractortype machines which will be used on theconstructional work of that company's newoil pipeline from Baghdad to Haifa. This

was the largest order ever placed in thiscountry for vehicles to be employed onoilfield work. Nearly 30o vehicles, mostlysingle deck buses and coaches, are being sent

of both passenger and goods vehicles, whilsta large post-war order for 5o double -deckbuses has been received from Bombay,Electric Supply Co. Norway, Holland andBrazil are three other countries for whichA.E.C. will be building chassis.

Launching Gear for Jet AircraftANEW device, known as the Electropult,

has been designed and built by theWestinghouse Electric Corporation for theUnited States Navy. The machine consistsof a linear electric motor, more than a quarterof a mile long, and is intended for launchingjet-propelled and robot 'planes and heavybombers from ships' decks or small landingfields.

The Electropult is essentially a hugeelectric motor laid out flat. The 1,382ft.track corresponds to the rotor of an ordinarymachine and the small shuttle car which runsalong it acts as the stator. In operation, a'plane is hitched to the shuttle car, whichspeeds down the track and tows the 'planeinto the air. In a recent demonstrationat the Naval Air Test Centre, Maryland,the Electropult launched a jet-propelled'plane at 116 miles an hour in four andone -tenth seconds after a run of only 34oft.Unassisted the 'plane would have required arun of about 2,000ft. for the take -off. Runningfree, without load, the shuttle car has builtup a speed of 226 miles an hour in slightlyless than 5ooft.

The shuttle car itself is r t Oft. long, Sift.wide, and extends Sin. above the track. Toharness the 'plane to the car a bridle of steelcable is used. The 'plane rides along thetrack on its own wheels and when flyingspeed is reached the car is stopped, the bridledrops off, and the 'plane takes to the air.

Atomic Electricity

AN experimental power plant is to bebuilt at Oakridge, Tennessee-one of

the original atomic research centres-for thedevelopment of nuclear energy in the genera-tion of electricity, Major -General Groves,Chief of the Manhattan Project, disclosedrecently.

A general view of the scene of activity in the engine shop. at the A.E.C. works at Sourhall,Middlesex, which is Working to capacity with export orders. The engines are " run in" here

before being fitted to the chassis.


The AutomaticEngine

Historical Notes and Particulars of the New" Automatic Brain," Designed by the National

Physical Laboratory

THE idea of using a machine to performordinary operatiome of arithmetic isvery old indeed. The beads on wires

in a child's play -pen are an example of theabacus used in Roman times for book-keeping arithmetic, still used in the East.The earliest true calculating machines wereinvented by Leibnitz and Pascal in theseventeenth century, but the work of con-structing them was unsuccessful. Engineer-ing technique had not developed sufficiently.

Hand -operated MachinesHand - operated calculating machines,

capable of addition, subtraction, multiplica-tion and division were made successfully inthe late nineteenth century. They were inuse in insurance companies and large busi-ness houses, and a few were in use inuniversity departments. Parallel develop-ments between the two world wars were in

made in the use ofall these types ofmachines, originallydesigned as the toolof the cost -accoun-tant and businessman, in scientificwork. Dr. L. J.Comri e, formerlySuperintendent o fthe NauticalAlmanac Office, is anoutstanding pioneerin this field.

He adapted a bankledger - postingmachine of Americanmanufacture for theconstruction a n dchecking of mathe-matical tables,

At work on the wiring of one section of the A.C.E. at Welwyn Garden City.

purely adding machines, and the largepunched -card accounting machines. Thelatter were developed originally for theAmerican census at the end of the last cen-tury, but their use increased in large businessorganisations and Government departmentsbetween the two wars. They were, in fact,used to demobilise the armed Forces at theend for World War II. For instance, ifit is desired to know how many butcherswill be demobilised in November, 1946, themachines can give an answer in a few hours.Human labour would take many days andmany hands to achieve the same result, witha far greater possibility of error.

Between the two wars great strides were

Computin

and used the punched -card accountingmachines for constructing tables of themotion of the moon up to the year 2000 A.D.In this way the speed and power of thecomputing aids for the scientific workerhave been greatly increased without anyduplication of the technical developmentalready undertaken in the commercial field.

During the war, however, it becameapparent that the needs of scientific researchwere outstripping the mechanisms providedby purely commercial development. AtHarvard University a machine was con-structed which, although its componentswere such as might be found in a commer-cial accounting machine, was put together

The multiplying unit of the Automatic Com-puting Engine. Through the wiring here seenpasses the calculations, which, in a few seconds,

give the answers to the problems.

in a novel way and with very different endsin view.

Modern MachinesThus came about the construction of the

Automatic Sequence Controlled Calculator,made by the International Business MachinesCorporation and presented to HarvardUniversity. It consists of 72 addingmechanisms, a mechanism for multiplicationand division, three tape feeds carrying tablesof mathematical functions and a punchedcard input and output.

These various mechanisms are inter-connected through what is virtually anautomatic telephone exchange, and the"instructions" to the machine are codedin the form of perforations on a punchedtape-the " sequence control " tape, whichcontrols the working of the machine. Thesetting up of a problem on the machineconsists in planning the sequence ofarithmetical operations to be performed,converting these operations into the codeused on the tape and punching it on a specialtypewriter.

The speed of this machine is not spec-tacular, multiplication takes a second ortwo, addition a fraction of a second.Division may take as much as a quarterof a minute, according to the number offigures involved. The new step in develop-ment in this machine was the idea that itshould tackle a problem as a whole, workingautomatically to a prescribed sequence ofinstructions. all previous machines the

126 NEWNItS PRAL. ICAL MECHANICS January, 1947

'

link between one arithmetical operation(addition, multiplication, etc.) and the nexthad always (except in a simple set of addi-tions) lain through the brain of the operatorat each stage. In this Harvard machine thelinks between successive operations areelectrical, through the built-in telephoneexchange. Instead of having to make theseconnections during the progress of the workthe human operator plans a long sequenceof them in advance and leaves the machineto carry them out automatically.

Although this Harvard machine is anindependent end original development, thepossibility of the construction of suchmachines and, indeed, more elaborate ones,had already been foreseen in this country.Dr. A. M. Turing, a fellow of King'sCollege, Cambridge, had written in 1936 aseverely mathematical paper in which hehad discussed the properties of suchmachines in connection with certainproblems of mathematical logic, withoutconsidering practical methods of construc-tion.

Now a telephone relay is a device forswitching a current on or off. A wirelessvalve can be used in the same way, butat much higher speeds. Sooner or later,therefore, someone was bound to attemptto make a machine which would use valvesin place of relays and attain hithertounheard -off speeds of calculation. This hasbeen done. At the Moore School of Elec-trical Engineering, University of Pennsyl-vania, there has been constructed anelectronic monster which will add twonumbers together in less than a thousandthof a second and multiply them in a fewthousandths of a second. This machine,christened the ENIAC (Electronic Numeri-cal Integrator and Computor) contains17,000 valves and consumes 150 k.W.

The A.C.E.The National Physical Laboratory of

the Department of Scientific and Indus-trial Research has, through its Mathe-matics Division, maintained an interestin these developments. It has planned amachine called the A.C.E. (Automatic Com-puting Engine), which will work at the speed

.of the ENIAC, or possibly somewhat higher,and which will take advantage of new tech-nical developments, making possible both agreater memory capacity and a higher degreeof complexity in the instructions.

The logical control mechanism of thismachine will be far more complicated thanthe calculating mechanisms. At these highspeeds time cannot be spared to prepare afull set of detailed instructions for eachproblem. Instead, instruction programmesfor standard calculations will be stored in aspecial library, and the instructions for aparticular problem will be assembled fromthese prefabricated units, possibly linkedtogether by special instructions. It is in theorganisation of these instructions that theNational Physical Laboratory feels that it hassomething new to contribute, and the majoreffort of the Mathematics Division has beenin the preparation of these instruction pro-grammes, for upon the form decided uponfor these the technical design largely depends.

It will be two or three years before thecompletion of this machine can be hopedfor, since its construction presents formid-able problems both mathematical and tech-nical.

To do its work the A.C.E. has to beprcvided with the equ;valent of three thingsrequired by the normal human mathema-tic:an. Firstly, there is the paper on whichthe computer writes down his results as he

.goes on ; secondly, there are the instructionsas to what processes are to be applied, whichnormally the mathematician carries in hishead ; thirdly, there are the function tablesto which the mathematician makes reference

when working out his problem. Theseproblems all involve storage of informationor mechanical memory, and the mechanicaldevice designed for this can be called uponby the logical control to give up its storedinformation at the required moment. Theinternal memory capacity of the A.C.E. willbe 75,000 decimal digits as compared to zoodecimal digits of the ENIAC.

One of the ways in which the greatermemory capacity of the A.C.E. shows itsusefulness is in the setting up of problems.Whereas in the ENIAC a problem must beset up by a laborious process of pluggingand switching, the A.C.E. may be told whatit is to do and will remember what it hasbeen told, The process of " telling" con-sists of passing a pack of cards through themachine on which instructions have beenpunched. This may take about a couple ofminutes, as compared with several hours inthe case of the ENIAC.

required to solve them, are so difficult as tobe almost impossible of solution by thepencil -and -paper mathematician. Suchproblems are well within the scope of theA.C.E. For instance, simultaneous equa-tions with- more than twelve unknowns arebeyond the patience and time of most mathe-maticians, but the machine will be able totackle equations with fifty or even a hundredunknowns. Problems for which the machinemight be used are the construction of rangetables, involving the calculation of trajec-tories by small arcs for various differentmuzzle velocities and quadrant elevations ;the calculation of the radiation from the openend of a rectanglar wave -guide ; the findingof the potential distribution outside a chargedconducting cube.

The machine will cost in the region ofDoo,000 to £125,000. It is unlikely thatother similar machines will ever be made.So great is the speed with which it will

Wiring another part of the automatic computing engine.

Internal WorkingThe internal working of the machine will

be entirely in the binary system, in whicha number is represented by a series of isand o's, the es being pulses and the o'sthe spaces between them. The answers willbe given in the decimal system. The fol-lowing table shows how digits in thedecimal system are represented in the binarysystem:

= I 6 = 1 to II = IOU

2 -= to 7 = III 12 = II00

3 = II 8 = moo 13 = not4 - too 9 = toot 14 = It to5 - 10I I0 = I010 15 = IIII

= tome>A thousand million has 3o digits compared

with the ten digits in the decimal system.The machine will work at very high speeds.

For instance, it is intended that the multi-plication of two ten -figure numbers shall becarried out in two thousandths of a second.The machine will alter the whole questionof what is a difficult and what is an easyproblem. There is a class of mathematicalproblems, which owing to their extreme com-plexity and the enormous length of time

work, that this one machine by itself will beable to cope with all the exceedingly abstruseproblems for which it is designed. Further-more; it is probable that during its construc-tion, or shortly after its completion, furtheradvances will become clear, and subsequentmachines will be designed to do even morethan the A.C.E.N.P.L. Team

The work is being done mainly in theMathematics Division of the NationalPhysical Laboratory. The leaders of theteam are Sir Charles Darwin, F.R.S., Direc-tor of the N.P.L. and a theoretical physicistof international repute ; Dr. A. M. Turing,in whose brain the idea of the A.C.E.developed, who is 34 years old, and who isnow with- the Mathematics Division ; Mr.J. R. Womersley, who is the Superintendentof the Division ; and Professor D. Hartree,of Cambridge University, who is the onlyman in this country who has worked theENIAC machine in the U.S.A.

The U.S.A. has been ahead of this countryin the design of calculating machines,although perhaps the British have beenmore resourceful in the use of the machineSthan the Americans. Mathematicians Pithis country have every reason to be gratefulfor the pioneering courage of the Americansin this field.


Rocket propulsionProblems of High-speed Flight Research

By K. W. GATLAND(Continued from page 89, December, 1946 issue.)IN the six previous articles, emphasis has

been on the rocket -fighter and thepossibilities of the simple ram=jet

athodyd. There is still much to be relatedof the strictly military aspect, but in order toobtain a more complete idea of the problemswhich, in view of the close proximity of thesonic " barrier " to aircraft speeds, nowface designers of fighters, it will be desirableto investigate the methods by which data isobtained to base the design of new types.

Prior to the advent of jet -propulsion,designers were little worried by compressi-bility. It is true that shock waves wereoccurring at local points on the aircraft, forinstance, behind underslung radiators andat wing joints, but by careful streamliningmost of the troubles were satisfactorilyovercome.

The position to -day is far more perplexing.In the past it has always been the power plantthat has lagged behind, and, very largely,it was the structural designer to whom creditwas due in improving performance of aircraft.Now, the case is completely reversed. Nolonger has the airframe designer to waitpatiently for the engine manufacturer tocoax a few more horsepower out of his alreadyhighly tuned product.

It is a fact that many jet and rocket enginesnow in production have quite considerablereserves of power which literally dare not beused because structures and controls arenot yet ready to withstand such great stressesas would be imposed at anything approachingfull throttle. So rapid is the rate of engineprogress that aeroplanes in project a yearor two ago and now approaching productionstages will, in the light of new design technique,soon be ready for the scrap heap. Witness thecancellation by the Air Ministry of the MilesM.52 contract.

Dangers of Compressibility ShockThe dangers of flight near the sonic region

were made only too clear in the tragedy whichovertook Geoffrey de Havilland while testingthe D.H.to8 tailless research aeroplane.An explosion in the 3,500 h.p. " Goblin "engine was the popular theory for the mishap,but this was soon discounted by de Havillandtechnicians. The more likely explanationis that the machine was flying at a speedapproaching sound values and compressibilityCaused its break-up, possibly upon encounter-ing an air -pocket. The vibrations set up inthe airframe under such conditions wouldhave been considerable.

What then, one may ask, is the best shape

Aircraft

Fig. 87.-An impression of the Bell XS -1 after its release from a specially modified B.29.In forthcoming tests it is hoped to attain speeds in excess of sound and to fly at over 15 miles'

altitude.

for such high-speed aircraft ? The answerto this question is open to argument, but highin consideration is the true " flying wing,"for in this form the weight could be spreadmore uniformly over the span. The cantileverwing and tailplane are the most vulnerablein orthodox aircraft because the air -flow isalways tending to lever them from the fuselage,a n d therefore a self-contained structurecontaining engines, fuel tanks and all othermiscellaneous equipment evenly distributedacross a single expanse of wing would befar less likely to receive a mortal blow as theresult of compressibility. The D.M.2,reviewed in last month's article, is an excellentexample of this type.

Higher flying speeds thus introduce aproblem of great magnitude-the risk of" flutter." Whereas at moderate fowardspeeds the air always has a damping effectand causes any vibration (started perhapsby a gust or a sudden movement of thecontrols) to die out rapidly, the opposite isoften the case when travelling at speedsupwards of 500 m.p.h. The damping qualitiesof the air may disappear or, worse still,actually contribute to building up the vibrationswith increasing amplitude, when the beatscan then become so violent that fractureof the structure follows within a very short

time. It is, therefore, obvious that theaircraft which go out to pierce the sonic" barrier " (about 76o m.p.h. at sea level)will have involved some knotty problems forthe design and stress technicians whoconceived them.

The structural problem, however, is byno means the designer's only headache. Hisefforts are required to perfect new controlsystems, both to maintain stability andpermit manoeuvres at high speeds, and yetenable safe flying in the low speed register.

At present there seems no alternativeother than to produce "compromise aircraft,"which means that form (exterior) efficiencymust always be impaired by the need for areasonably moderate landing approach. Inany event, there does not appear to be a greatfuture for aircraft which fall out of the skyat 17o m.p.h., as the Miles M.52 supersonicresearch aeroplane was intended to do.

Flying Wings and Supporting Jets ?To satisfy both structural and aerodynamical

problems at high speeds, the flying winglayout then emerges as the logical development.Small wing area, knife-edge sections, acutesweep-back-these are the more obviousrequirements for trans -sonic and supersonicflight, making the aeroplane efficient inreducing drag at high speeds but, alas, poorin qualities of lift at the time of landing.An ultimate solution may be found in the useof turbo -jets balanced by three -axis gyros toprovide an upward or supporting thrust,permitting the aircraft to hover and descendslowly in the same manner as a helicopter ;but this is mere speculation as yet. However,there does not appear to be an alternativeanswer, unless one considers folding or partlyretracting wings; but few to -day would suggestthat either of these schemes was practicable.

There is little doubt that as flight loads riseand wing areas diminish-as it seems logicalto expect in the attainment of increasing speed-landing will present one of the pilot'sgreatest hazards.

FrictionThe difficulties that manifest themselves

when flight in or above the speed -of -soundFig. 88.-Small athodyd ram -jets have been fitted experimentally to the Bell X-83, develop-

ment of the " Airacomet."


range is considered are truly enormous. Not bi-fuel rocket engines and not from turbo -only has the structure to be of herculean jets or athodyd ram -jets. A possible explana-strength and the control system such as to tion is that confusion arose from the fitmentpermit safe flying at all speeds but friction of athodyd units at the wing tips of a Bellalso gives rise to concern. XP -83, development of the " Airacomet "

The heat generated by air buffeting. may (see Fig. -88),- which, incidentally, crashedbe as much as 400 degrees at 1,5oo m.p.h., during a recent test flight.and so it is reasonably safe to say that pilots The fuselage is packed tight with fueland crews will need refrigeration. A solution tanks, and the pilot, clad in a pressure suit,to some degree, however, is found in flight fits snugly into the bullet -shaped nose, whichat great heights. At 8o,000 feet, for instance, had actually been designed to suit the dimen-the outside temperature will be 67 degrees sions of Jack Woolams, the firm's test pilot.below zero and thus, in order to eliminate Short -span thin -section wings and tail -as much bulky refrigeration naachinery as assembly are also the vogue.possible, forthcoming test flights are being The machine had already completedplanned to take place between 6o,000 and satisfactory glide tests, having been taken up

- 8o,000 feet up. Eventually, it is reasonableto expect that all flights by long-distancejet -driven aircraft will be in the stratosphere,for not only does the heating problem findpartial solution but drag reduces with altitude.At 6o,00o feet the drag for a given speedwould be approximately one -fourteenth asmuch as it would be at sea -level, or, in otherterms, only one -fourteenth of the powerwould be required for propulsion. A climbto 8o,000 feet and the resistance becomesone -twentieth that at sea -level, one-half thatat 6o,000 feet.

This would be an encouraging prospectbut for the fact that the efficiency curvefor the jet -engine begins to fall off aroundthe 60,000 feet mark. The turbo -jet and theathodyd require vast volumes of air to operate,and again the compromise path is the onlyone left open. Whether the rocket engine,which-at this stage it is surely unnecessaryto stress-operates independent of atmosphere,will eventually rectify this state of affairs isyet to be seen, but its voracious appetite infuel would seem to limit its applicationin all normal conceptions of commercialaircraft. A ceiling of 55,000 feet, at least,should give a reasonable operating efficiencyfor high-speed turbo -jet and athodyd-drivenairliners, and this is some consolation.

DefinitionsIn this vast study that is opening up in

flight at ballistic velocities, it is inevitablethat new terms will creep in to augment thealready extensive aeronautical vocabulary.Already, aerodynamisists have presented uswith several additions, and it will be as wellto explain some of them. Mach number, forinstance, is the relation of flight speed tothe speed of sound, M=t, and hence,Machometer, an instrument recording therelation of flight speed to the speed of sound.More familiar are the speed zone terms:subsonic, less -than -sound ; trans -sonic, rangeof speed lying between M =0.8 and M = 1.2 ;supersonic faster -than -sound ; and then,compressibility, phenomenon occurring asflying speed approaches sound values, causingsudden change in density and pressure withaccompanying increase in drag and decreasein lift. Shock waves are a wave formation-the outward (and under certain conditionsvisible) sign of compressibility.

Having summarised briefly some of theproblems related to flight at trans -sonic andsupersonic speeds, it is now possible toinvestigate matters a trifle more fully in thelight of work that is proceeding with high-speedresearch aircraft, both manned and unmanned.

Undoubtedly the most significant of thesespecial types is the Bell XS -I, a machinesaid to be capable of 1,5oo m.p.h. at 8o,000feet altitude. Some confusion had arisen inearly descriptions of this project, for it wasoriginally said to be athodyd-driven andto incorporate a rocket booster, but a recentPress release by the manufacturers has nowclarified matters and an impression of themachine is given in Fig. 87.

The XS -I has a strong outward resemblanceto the Miles M.52 supersonic research air-craft (work on which was abandoned lastFebruary), but its power derives from four

4.0

3.0

0 0

reasonable to expect the throttle to be pushedinto " maximum boost."

The voracious consumption of its motorswill limit the duration under power to withina few minutes, but, nevertheless, having beenreleased at- a height of about 35,000 feet,the pilot is expected to climb to between70,00o and 8o,000 feet before making hisbid for maximum speed.

The XS -I has been constructed by theBell Aircraft Corporation with co-operationfrom the Material Command of the ArmyAir Forces at Wright Field and the NationalAdvisory Committee for Aeronautics. Thefour bi-fuel rocket engines were built bythe Reaction Motors, Incorporated, a firm

inaugurated during the warand which was responsible formany of the power units ofAmerican guided missiles.

A recent disclosuresuggests that the new unitdevelops 6,000lb. thrustat sea -level and that itsdevelopment occupied thefirm in research for four

700 Q years. It is more powerfulthan any of the Walter

600 bi-fuel engines and has afar greater operating

500 efficiency.The unit may be presumed

400 Q to be a developed version ofthe rsooN4C, weighing

300 nolb., and consisting offour cylinders, each capableof delivering 1,5oolb. thrust.Each cylinder contains an

/00 igniter, combustion chamberand expansion nozzle.

What fuel the machinecarries has not yet beenmade known, but it isprobably an alcohol com-pound with liquid oxygen.

Low Speed Research withSupersonic AerofoilsAn attempt to obtain

reasonable liftingcharacteristics in super -

2.p sonic section wings at lowforward speeds is seen inthe tests of a full-scale wingand tailplane of the projectedM-52 on a Miles M.3B" Gillette " Falcon, basicallya Falcon Si, four -seatmonoplane powered by aD.H. Gipsy Six Series IIin -line engine.

The fuselage of thedeveloped Falcon is thesole link with thecommercial version, and

even the fully trousered undercarriage,originally rooted in the wings, has beenreplaced by a strutted chassis fixed aroundthe cabin under -fairing. This haselminated any possibility of turbulence inthe air flowing over the " knife-edge "bi-convex wings, which, incidentally, were ofall -wooden construction and high -glossfinished.

By the time all modifications had beencompleted the Falcon was a single -seater,with the cockpit fitted out with a formidablearray of special recording instruments andtwo additional fuel tanks. Flight tests werecommenced in August, 1944, and whenthe machine was satisfactorily trimmed anM.52 -type tailplane with independentelevators was fitted. This arrangement,however, was eventually displaced by a special" all -moving " tailplane.

The comparative figures for the two versionsare given below, with the Falcon " Gillette "

-data quoted- in parentheses for easy referencu,Dimensions : Length, 25ft. (25ft.) ; span,35ft. (29ft.) ; height, 6ft. 6in. (7ft. 9in.) ;

Turbo-Jar

Afbodyd

turbo

0 0.4 0.8 1.2 1.6

200

0

Mach Number

1

I 1 1 I

0 200 600 1,000 /,200

AIRCRAFT SPEED (MPH)Fig. 89.-A graph prepared .from figures given by Dr. S. G.Hooker, of Rolls-Royce, Ltd., comparing a high -output turbo -jetwith an athodyd ram -jet at 40,00oft. altitude. In the inset,the author illustrates a logical development, a tailless fighterwith athodyd units at the wing -tips, and a booster rocket in

the tail fuselage.to about 30,000 feet beneath a speciallyequipped B-29 and released. Woolams wasloud in his praises of its flying qualities,and so successful in fact were consideredthe preliminary tests that preparations werein hand for the first flight under power.

Everything went according to plan-untilthe tragic news was- received that Woolams,,having entered a special P-63 in the BentixTrophy Race, had crashed to his death.

Now, with a new pilot at the controls, afurther series of glide tests will be necessary,and it may be months before thoughts canagain be directed toward powered testing.

When, however, the XS- I eventually dropsaway _from its parent B-29 and for- the firsttime shoots away under power, it will not bejust a " do-or-die attempt to out -fly sound.The beginning of another testing phase,doubtless even more extensive than theprevious glide flights, will have begun, andonly when the machine has performedsatisfactorily at moderate subsonic speedsand the pilot has gained some experienceof flight at really great altitudes will it be


wing area, 181 sq. ft. (16o sq. ft.) ; weights :empty, 1,55o1b. (r,73o1b.) ; loaded, 2,5251b.(2,5oolb.) ; performance (speeds) : maximum,18o m.p.h. (164 m.p.h.) ; landing, 40m.p.h. (61 m.p.h.).

Work on this enterprising little researchaeroplane was abandoned when the contractfor the M.52 was cancelled. The data obtainedfrom its numerous flights, however, must haveproved of immense value in designing theparent machine, and in view of the vastspeeds expected of future aircraft it is obviousthat more and more attention will need tobe paid to research toward ensuring safetyin flight at low speeds.

Control ProblemsThen there is the problem of maintaining

control at high speeds. In orthodox aircraft,the first effects of compressibility manifestthemselves at about 500 m.p.h. ; controls

stiffen and become sluggish, and as speedincreases still further, the pilot has greatdifficulty in manoeuvring his aircraft.

Several possibilities have been suggested,and one of the most promising is illustratedin the fitment of " drag rudders " at the tipsof the new XP -79B flying -wing fighter.These consist of small open ducts, the areaof which can be moderated independently.To cause a change in direction to port, it isnecessary only to restrict the flow throughthe port duct. The drag built up on that sidethen naturally results in the machine turning.

A similar scheme is the fitment of smallrocket motors at the tips, but this wouldbe rather wasteful in fuel.

In future high-speed aircraft, especially infighter types, there is little doubt thatathodyd ram -jets will occupy the space atthe wing tip, with turbo -jets or rocket units

mounted inboard, either in the fuselage or atthe wing roots. It should then not prove toodifficult a matter to incorporate the principleof the " drag rudder " in the athodyd motor.A device to vary the area of the intake wouldsatisfy the problem admirably,

The light weight of the athodyd makes itideal for installation at the wing tip (seeFig. 89), and, indeed, this is the logical stepto expect from the successful carriage of" overload " fuel tanks and bombs in thismanner, an arrangement first tried on the" Shooting Star " and which is now commonpractice in the U.S. Wind tunnel tests haveshown it to be a most efficient location owingto the inevitable formation of vortex. Astreamlined protuberance at the tips, there-fore, involves no great increase in drag, andwith athodyds the form efficiency may beexpected actually to benefit.

(To be continued.)

Science NotesBy Prof. A. M. LOW

TT will be interesting when the cinema.1. gives us a reasonable imitation ofstereoscopy. Perfect colour, extreme speed,with probably a few smells thrown in.Some of the films that I see are a terriblewaste of our celluloid that ought to be devotedto discovery. Not so long ago there was agreat discussion as to how a fly landed on aceiling. Did it fly upside-down, or did itdo a somersault at the last moment ? High-speed pictures have soon illustrated that thesecharming insects either make a half -loop orhalf -roll, as our pilots say, a few inches fromthe ceiling, thus making a perfectly goodsix -point landing. Yes, they have six legs.For many years Plato gave the number asfour, which was considered to be so logicalthat no one ever troubled to look. Thatprobably was an early instance of the badmethod of learning by alleged logic insteadof by the best of all systems-that of scientificobservation. The fly, I should mention, hasfree feet, which can easily hold on to thesmall hills and dales of a whitewashed surface.Under a microscope, a ceiling looks like themountains on the moon, a razor edge like asaw, and the most beautiful skin in the worldlike a rather ancient toad. As I explainedbefore, everything is relative, and beauty isin the eye of the beholder. I want to makeit clear that the fly knows that also.

Are You Wrong ?TT is extraordinary that popular errors.1. should last so long. Lightning is notattracted by your penknife on the table.A few miles of air are much more important.But that is the interesting point. There isnearly always some slight truth in a fallacy.To suppose that a small piece of steel couldmake any difference to a lightning flash isridiculous, but it is true that the lightningwould prefer to pass through steel rather thanair. The sun does not put out the fire, butmakes it more difficult for you to see whetherthe little flame is there, and prevents yourdiscovering so quickly that the wretched thinghas gone out. Pokers leant against a gratedo not increase the draught, but I supposethey would do so to an extent that couldhardly be measured by the most sensitiveinstrument. I often think that some of themost laughed -at sayings of our grandmotherswere very true. At one time it was commonpractice in the West of England to scrape themould from a copper kettle which had beenleft in a dark cellar and to use this mould forcuring septic wounds. Humiliatingly likepenicillin, is it not? We all know that bee

venom is an important medicament, but I amsure that doctors who had said so forty yearsago would have been condemned as quacks." The hair of the dog that bit you " is a verycommon phrase, yet to dissolve the hair of acat and to inject the resultant liquid hasproved very useful in the diagnosis of asthma.Many sufferers are greatly affected by thepresence of a cat. I am no believer in witchdoctors, but when they used to stick pins intoa wax image it is not impossible that thiswas merely a mascot which helped them toconcentrate thought, and that the result wasmildly inimical to their enemy. No doubta far more common case was the surreptitiousdose of poison, but I would not like to statethat the witches, on the other hand, werequite all nonsense. One should be verycareful before stating a fact without adding :" Or so it seems to me."

Don't Hurt the SnailNATURE designed her products so much

better than any human being could hopeto emulate. Nature also knows all about speed.A jet of water travelling fast could knock ahole in you; travelling slowly it is fars ofterthan butter.

Put a razor blade edge upwards and a snailin front of it. The snail will climb over thatblade using its own lubrication so that tinyparticles of mucous substances act as rollerbearings. It moves so slowly that it willsafely traverse a bridge which even a fakirmight find very troublesome.

Child's PlayHERE is a simple problem to which any child

should be able to give an answer ; yet itis one which can puzzle all of us very easily.

When a fast bowler is practising spinning aball can the ball progress faster after its firstbounce than the speed at which it is originallythrown ? I should say " yes," because he mightthrow it very slowly, but with so high a speedof rotation that upon contact with the groundits peripheral velocity would be far higher thanthe rate of its forward motion. So it will jumpforward or sideways.

This Easter -egg -shaped pressure chamber was specially designed for Mr. Winston Churchill whenhis doctors had warned him of the danger of his flying at a greater height than 8,000 feet. The

cabin is fitted with a comfortable couch, ash trays, cupboard, bookshelf and telephone.


Britain Can Make It ExhibitionNovelties, Inventions and Gadgets.

By the MARQUIS of DONEGALL

The latest in Television, with an easy chair to match.

WHEN the Editor discussed the subjectof this article with me he men-tioned gadgets.

What is a gadget ? The Oxford Diction-ary is of singularly little help. It says:1886. Origin obscure. Originally innautical use. (That I can well believe havingrecently seen the Queen Elizabeth.)Continuing with the Oxford Dictionary: "Asmall tool or piece of mechanisin, especiallyof a trivial nature."

Now I come to think of it, my life isconditioned by gadgets: saved, once ortwice, by my Sperry horizon and gyro whenI was piloting. I was sorry not to be ableto find Sperry represented in Britain CanMake It, but probably they have not beenable to produce a supplement to the cata-logue giving a list of all the firms represented.

Quite apart from gadgets that have savedmy life I have, as most gadget -mongers willagree, quite a number that have nearly killedme on occasions.

But our objectiveis Britain Can MakeIt. Starting fromthe basis that every -t hin g, from thewheel to Eadar, musthave begun as agadget, the field isunlimited, and myonly task is to differ-entiate between whatwas a gadget in5,000 B.C. and whatis a gadget in 1946.

Later in thisarticle I propose todeal with the" Designers LookAhead" Section.This cannot be dealtwith all at one timebecause some of it isimmediately practic-

able and other parts of it are practicableonly on the drawing board.

Midget PortableNow let us get some gadgets listed as we

go round the Exhibition. One of the firstthat we come to, photographed as often as afilm -star, is the Romac first British MidgetPortable radio. I feel that most of myreaders must know about it, as it has had somuch publicity. I have one, and believe me,it is better than any American.

Then we have the collapsible containersmade by the Bristol Aeroplane Company ; aninternally sprung metal container so that youcan return the container in a fraction of the

A streamlined cycle, designed by Mr. B. G. Bowden. The rnachintihas a dynamo and motor set, and is shaft driven

Model of a third-class sleeping car providing accommodation for 34 passengers in private two -bunk and single -bunk cabins.


space in which it went out with its freight.The Bialaddin pressure hurricane lantern -ismore modern in design than any hurricanelantern I have heretofore seen (ExhibitNo. GG8 by Aladdin Industries, Ltd.,Greenford.)Electric Irons

There is nothing much new in the electricirons, but I suppose that GG5t by ,Clayton,Lewis and Miller, of Southend, could beclassed as a gadget on account of its small-ness. It is very attractive in red and black.

GG54 in the catalogue qualifies as agadget and is made by the Hotpoint ElectricAppliance Co., London. This appliance,starting from low heat, has an adjustablepointer which designates art silk, silk, wool,cotton, linen, and ending up at high heat.

GG35 is a very nice plate -warmer byEnglish Electric, of Preston, although Idoubt if there is anything gadgety about itexcept its extremely attractive appearance.

I was interested in the latest Hoover(GG24) on account of its edjustability tovarious house-cleaning jobs ; rather like thedevice that enables the dentist to insert his.various instruments of torture into the sameappliance.

GG45 is a most attractive black and gold

.A clock with chromium bezel and stand. Spunsilver centre, black hands, white zone, black ongrey markings. Height Tins., width 6ins., depth'.21ins. Designer, Robert Giuman, of London ;

movement by Ferranti.

Thermovent, by Ekco, of Southend. For theuninitiated, such as myself, theY are things.that, by the use of a concealed electric fan,blow hot or cold air at you, as desired. Itmay be very nice, but it isn't really what we'call air-conditioning.

There is nothing. much new in the water -heaters. I like GGI tz purely for the designof Mr. Wornum, F.R.I.B.A. It is finished ingreen and cream.

GGI t x is a modern black and white" Ascot 7 heater. I particularly like the EkcoPlastalite red table lamp (GG7o), althoughno new principle is involved.Household Steps

Now to another section; where we findsome very attractive steel steps by SebelProducts, of London (T143). It will be a

A panorama in the Toy Section.

relief to my fellowsufferers, as handymenhusbands, to know thatwe will not have tohump wooden thingsround any longer tomend a fuse. While Iam on this subject, wemust include the pair ofhousehold steps whichcan be named into an ,ironing board or ababy's high -chair.

Housewives shouldbe delighted withBritish Emulsifiers'(T197) hand - fittingsaucepan handles. The

handle is shaped to the fingers so that thereis no danger of a " slip."

Whether you call Nylon wigs a gadget Ido not know. But they are magnificent, andyou will find them in the Fashion

Toy SectionWe now have to visit the toy section, and

I ani not at all sure that the toys are notthe- best of the lot. There is, of course, theinevitable pedal jeep (L5o), by Messrs. W. E.Green, and I wish that the " Jazz -minor "drum set (LIA5) had been available when Iformed the jazz band at my school in 1919.I had to make mine.

LL228 is a beautiful scale model alumin-ium'duhiP-wagon. It is made by Woodnote,Of London.

Kitchen with dining recess in small modern house, designed by Frederick MacManus,F.R.I.B.A.

132 NEWNES PRACTICAL MECHANICS

A modern portable plate rack

Ther is also LIA 4-a grand aluminiumscooter, made by H. G. Stone and Co., ofLondon. Another fine toy is LL454, a grab -crane by Ridingbery, of Bristol. Thispicker -upper is finished in red, manoeuvr-able, with a seat, and is called a " Rotascoop."

The construction units for children areremarkable. I mention invidiously LL29o,an electric construction unit which enablesthe youngster to build a bell -circuit or anelectric -light circuit, by Jungle Toys, ofLondon, and LL399, a chemistry unit byEkco, which enables the kids to make theirown " stinks," and (I hope not) blow thehouse up!

There is also a very workmanlike search-light unit (LL3) and A.A. gun, by AstraPharos, Ltd.

Through the men's department and,although it is a pre-war idea, the putting ofstuffs on to trees to represent the leaves, ifartistically executed-as it is at the Exhibi-tion-is arresting.

Designers Look AheadAs we try to find our way to the

" Designers Look Ahead " Section we passa very modern -looking lawn -mower (St I).It is said to be a Power -Scythe, by Roto-scythe, of Slough. I'd call it a petrol lawn-mower, but the catalogue is probably right.

As we enter the " Designers LookAhead " we have to be very careful. Asgadget -mongers, we hate things that do notwork. We tolerate things that could work,given the materials, labour, etc., and we notedown as negligible the more fantastic. Sowe must divide our section.

(A) Things that work. None.(B) Things that could work.

(a) The Sleeping Car.(b) The Yacht.(c) The Globe Radio.(d) The New Taxi.(e) The Portable Sewing Machine.(f) The Larger Screen Television.(g) The Convertible Trailer -House.

(C) Things ThatMight WorkSomeday.

(a) That Bicycle.(b) The Space

Ship.Let us take first the

Things That CouldWork within a reason-able time.

The sleeping car,third class ; takes 34on the double-deckerbus principle. Singleand two -bunk cabins.

Throws a cup ofhot tea at you, it'salleged, for a penny inthe slot ! Ugh !

Is " this happybreed of men, thislittle world " thatpours our tea accord-ing to our tips, thus tobe ousted ? Nay !For Mitropa, Wagon-Lits and graft, intothe purse, dearfriends !

The yacht is fine. Isee no mechanicalreason why it shouldnot sail on the flying -boat principle, thoughI can't see it ever get-ting up on the " step,"except in a hurricane.(And that would notbe so funny !) Icannot see that any-

body could complain about the dream taxi.All it needs is a perfect taxi-driver. It isconstructed to carry bicycles, has a duplicatemeter inside, and controlled indicator toshow when it is free. (There is no mentionof what happens to the indicator when themeter has a glove over it.) Apart from that,the doors open hydraulically, like the under-ground.

January, 1947

The portable sewing -machine is just anormal development. It is surprising that it hasnot followed its cousins of the radio and thetypewriter before. Maybe, the ladies are lessubiquitous with their sewing than B.B.C.fans or journalists.

No reason whatever why there should notbe a larger screen for television. It has beendone, years ago. The trouble is that whatyou gain on the swings, you lose on theroundabouts. I gathered that as the late -lamented Baird tried to drum it into my thickskull. It is practicable to -day, of course.But, like many things, it is not commercial.

Convertible Trailer -houseThere only remains the convertible

trailer -house. As far as I was able to see,you pull everything out of your trailer tobuild yourself a temporary house on theprinciple of children's construction sets.There was such a crowd when I saw thisexhibit that I hope I am right. Anyway,if I am wrong, it is a good idea for somebodyto work out.

Frankly, I don't like the " Globe Radio "as a gadget. The idea is that you have anilluminated map of the world on your walland you " plug in " your operative unit in ahole denoting Sydney, or other selected townon the map.

The object is that the thing should be awall decoration. But I think that I knowmy radio friends well enough to state thatthp would rather fiddle with knobs untilthis new system is perfected to a degreethat knob -twiddling cannot touch. And thatis years ahead.

There you are, my friends, the thermo-static bed will undoubtedly work. Personally,I am old-fashioned and like my sheets andblankets-and, if necessary, a mosquito net.If this ridiculous unborn contraption wereportable, worked on dry batteries, wereproof against all forms of pests from fleas tomosquitos, that might be something. Atpresent I am not impressed, and prefer mydouble bed.

Aviation NotesA Flying Workshop

AMONG the great variety of uses for whichthe Bristol Freighter is exceptionally

suitable, the " flying workshop " is anexample which makes the maximum possibleuse of those advantages inherent in thedesign of the aircraft. To -day, if mechanicalbreakdowns occur on engineering or industrialprojects in remote areas, valuable time isinvariably lost while spares or special equip-ment are brought up by surface transport.Using a Freighter equipped as a workshop," breakdown gangs ' could be on the spotwithin a very short time of any mishap.

The spaciousness of the Freighter's interiorpermits the installation of a variety of machinetools, storage racks, and bins for spares.The floor, designed to support a unit load ofzoo lb./sq. ft. with specially strengthenedstrips on either side to accommodate vehicleswith a wheel loading up to 5,000 lb., givesample strength for the mounting of equipmentfor light machining operations or work of asimilar nature. Full scope for the easymanipulatiotT of bulky material and freedomof 'Movement for the work is provided bythe length and width of the hold, while thefloor in the Freighiei slopes only a little, unlikethe floors of most aircraft with conventionalundercarriages.

Machinery could be installed and sparesloaded with a minimum of effort and withina very short time thiough the wide -nose doors

and, with the door sill but 4ft. 6in. from theground, only a small loading ramp wouldbe necessary.

Able to operate from the most indifferentlanding grounds, the Freighter needs only acomparatively short landing or take -off run,and the aircraft is robust, easy to fly, andeconomic.

The Bristol " Wayfarer "MAKING a perfect landing at Bjornholm,

Denmark, on a grass runway only 500to 600 yards in length, a Bristol " Wayfarer "amazed pilots and representatives of DanishAir Lines (Det Danske Luftfartsselskab) whowere examining the performance of the aircraftwith a view to purchasing Wayfarers orFreighters for operation in their service.

The landing at Bjornholm-" Pearl of theBaltic "-followed a North Sea crossing fromCopenhagen recently during which theWayfarer cruised at an average speed of18o m.p.h. during the 540 miles journey.

The Danish pilots were quite convinced thatthe aerodrome at Bjornholm would be toosmall to land so large a machine as the" Wayfarer " and that Mr. A. J. Pegg,the Bristol pilot, would be obliged to returnto Copenhagen without landing. They wereastonished when Mr. Pegg made a perfectlanding on the short grass runway which,until that moment, had been used only formachines of a much lighter type.

January, 1947 NEW NtS . PRACTICAL MECHANICS - 133

The Triumph Springy WheelEVER since the days when a reliable spring

fork was devised, such as the oldDruid type, thoughts of both designers

and riders have turned towards adequaterear suspension, and when one considers themultitudinous designs and -schemes that havebeen marketed since the first world war andbefore, it is quite obvious that the solution tothis problem is both complex in principle anddifficult of solution in practical manufacture.

From the earliest attempts, such as the Batseatpillar, the enclosed P.V., on to the Matchless,not forgetting the classic A.B.C. of opposedleaf spring articulated arrangement, all havefailed one way or another to stick, until wecame on to the more modern attempts thatlargely centred round the plunger type, whichwas grafted on to a more or less normal frame.To -day there is no marked ascendancy of the

plunger Norton Ariel type over the articulatedtype of the Velocette racing scheme, theH.R.D., etc. Quite obviously these twoentirely different layouts have advantages anddisadvantages which vary in ratio accordingto the purpose for which these machines havebeen primarily designed, but each has thedisadvantage of increased weight, considerablyincreased cost, and the possibility of eventuallack of rigidity as the parts wear. Therefore,when it was decided that Triumph shouldendeavour to provide a solution to the rearspringing problem as far as that company'smachines were concerned, the requirementsthat any scheme would have to meet were setdown in the order of their importance. Theywere :

1. Maintenance of lateral rigidity.z. Minimum unsprung weight.3. Minimum total increase in weight.4. Moderate cost.5. If possible a device which could be

used on machines already in serviceand bought as an extra.

These last two items unfortunately arelikely to be affected by the present difficultconditions, but even so these conditions, itis to be hoped, cannot be regarded aspermanent and are bound to improve as timegoes on to enable manufacturers once moreto get back to moderate cost and availabilityof supplies.

It was visualised that if an efficient devicecould be incorporated and self-containedwithin the back wheel, it would leave mostof the machine unchanged and would obviatemany of the disadvantages of the existingspring frame. Tests also proved that it wasnot the amount of movement that made sucha difference to road -holding and comfort somuch as the deflection curve characteristicsof that movement. A large uncheckedmovement is much more disconcerting to therider than a small controlled movement forminimising the effect of a bad surface. Thepresent invention gives adequate movementfor all requirements over normal roads andhas a marked effect on the controllability atvery high speeds, with a distinctly pleasant,soft ride at normal touring Speeds. Moreover,it adds very little to the total weight of themachine-some 12 lb.-which, expressed interms of percentage extra on 360 lb. in thecase of a 500 c.c. " Speed Twin," is only3 per cent.

Constructional DetailsFrom a structural point of view,

although triangulation in motor -cycle framedesign has been aimed at, only a semblanceof this has been achieved in the two rear

Notes and Constructional Details

triangles of the back stays. These arenormally trussed by a fairly rigid spindle sothat the rear portion of a motor -cycle at leastis fairly rigid. With a plunger frame or withany type of spring frame this rear trianglegoes by the board and, therefore, althoughthe spring frame proper may be a compara-tively rigid structure, it does not make forrigidity over the whole of the machine fromfront spindle to rear. With the spring wheel,the two rear triangles of the frame are braced,as with a rigid frame, substantially and rigidlywith a fairly massive spindle which isstationary, and from this basis the rest ofthe scheme is worked out. This rear spindlesupports a curved rectangular male guide.which encloses springs. This guide is'embraced by an aluminium box structurewhich is free to move vertically, describingan arc which is exactly that formed by theradius struck from the centre of the gearboxdrive shaft. This movable bearing box carriestwo large diameter special races, developedand made by Triumph, on which the roadwheel revolves. Attached to the road wheelis the sprocket and brake in the normalmanner ; thus whatever position the wheel

has shown much improvement over thestandard braking on the fixed wheel, thisPartly because the brake is larger and partlybecause of the better wheel adhesion. Theunsprung weight is of course only a portionof that of the wheel and represents theminimum possible with any resilient scheme,thus fulfilling the requirements of item No. 2.

It might be pointed out that this wheel isthe subject of an invention for which apatent was' granted in August, 1940, and wasapplied for in February, 1939, well before theoutbreak of war, and it would have beenoffered to the public in 1941 had the war notbroken out. Unfortunately, as is now wellknown, the whole factory and all its existingprototypes of experimental work were com-pletely destroyed in 1940, and with it thewheel on which so much painstaking testinghad taken place. Drawing records in thiscase were also destroyed and the whole workhad to be started again when the firm'scommitments permitted.

Part -sectional view of the Triumph spring wheel hub, with one of the end plates detached.

may take by movement, the chain tensiondoes not vary even minutely. The bearingbox carries replaceable metal pads whichguide complementary sliding pieces on themain spindle. This takes the main pull ofthe chain and braking loads. These rubbingsurfaces are enclosed by synthetic rubberdiaphragm seals which, however, are staticand merely cope with eccentric'ty, thuskeeping all road dirt away from the rubbingsurfaces. The road wheel hub is large enoughto clear the vertical bearing box enclosing thesprings. There is a certain amount of frictionbetween the bearing box and the malestationary guide, and although lubricated bygrease, provides just the amount of dampingrequired to prevent the wheel from beingtoo lively. It has been found over manythousands of miles of tough road-testing that

this damping does not vary and the designprovides for a fixed value which has beenfound to be adequate. The brake plate withthis device needs to be fully floating, as thebrake reaction is taken on the frame and not

by the spindle of the wheel. By a suitablelinkage this has been found to be entirelysatisfactory and, incidentally, the brakingwith Sin. brake provided by the new wheel

It is not without amusement to reflect thatat one time the spring wheel was the inventor'sdream, and a visit to the Patent Office willshow a large variety of schemes and inventionsto make practicable a wheel, where the hubscould run eccentric to the rim, and whereasthe pneumatic tyre made most of these inven-tions unnecessary, the peculiar requirementsof the rear suspension of the single-trackvehicle have brought forward the presentspring wheel, which is not claimed to haveany advantages over pneumatic tyre-actuallythe functions of each are entirely separate-but to be used supplementary to it. Manyreaders may ask why a similar device couldnot be used for the front wheel. The answeris that it could, but the lifnitations of thescheme prevent sufficient movement for it tobe an effective substitute, whereas it isexcellent on the rear. The characteristicsof this wheel have been studied in relationto the Triumph telescopic forks and thecombination gives splendid control at veryhigh speeds and, incidentally, a mostcomfortable ride to the pillion passenger.

MaintenanceWith regard to maintenance, there is very


little on the wheel, apart from an occasionalram with the grease gun that is only requiredover thousands of miles, and although thebearings were originally adjustable, they arenow fitted at the works with the requisiteclearance and have been found to wear forsuch a long period without adjustment thatthis has been scrapped in favour of shimswhich can be removed to take any slackthat may occur over very long mileages.

With the help of the accompanying illus-

tration, the comparative simplicity of thescheme will be apparent, although it entailsa special technique in manufacture whichhas set many problems, now overcome. Thebody of the hub is in high duty alloy andprovides for direct -pull spoking. In actualfact this has approximately the same diameteras the sprocket, and one has to look twicebefore one realises there is anything differentfrom a normal back wheel.

Although in practice this wheel will fit

all Triumph machines going back to 1938.it is unlikely that any will be available for oldmachines until the supply improves. Thepurpose of publishing a description of thishub is to keep riders in touch with the develop-ments of this Company, but unfortunately,until the supply position does become morefavourable, there is no guarantee that sufficientwill be available to meet all orders for 1947machines, on which it will be offered as anextra.

The Man-made PlanetA Description of a Space -shipto be Powered by Atomic Energy

AN atom -powered space -ship, capableof travelling to and from the moon,and described by its inventor, Mr.

Warnett Kennedy, as a " man-made planet,"was one of the features of the " Designsof the Future " section of the " Britain CanMake It " Exhibition.

The exhibition demonstrated the remark-able developments now taking place in allbranches of industrial design. The specialsection in which the " space -ship " wasexhibited was planned to show, from thestandpoint of existing knowledge, the linesof likely development during the next twentyyears.

Incorporated in the setting of the " space-ship " exhibit was a photographic record ofsignificant stages in rocket developmentfrom earliest conceptions to the first atombomb.

Atomic PowerAtomic power demands a complete change

of outlook on the construction of space -shipsand the use of energy. In the past the prob-lem has been to make the best use of limitedpower. But scientists can now proceed on

The space-ship interior,showing

observation bycamera obscura, andnavigational controls.

A model of the space -ship, showing the trans-parent outer shell.

the assumption that energy for space -flightis theoretically unlimited.

Until the later stages of the war publicopinion was sceptical of plans for inter-planetary travel. A space -rocket wasregarded as a glorified firework. Derisionceased, however, when the V2 rocket bombturned the firework into a dangerousweapon ; and rocket fuels themselves wereoutmoded as a source of power for spaceflight by the atom bombs at Hiroshima,Nagasaki and Bikini.

Problems of DesignStimulated by the implications of atomic

power, Mr. Warnett Kennedy realised thatthe idea of a streamlined space -ship wasout of date. It became legitimate to assumethat a space -ship need not begin its journeyat volent speed. Air resistance at slowspeed was negligible, and the depth of theearth's atmosphere was only a fraction ofthe distance to be covered in inter -planetarytravel.

It became possible also to devise an alter-native to existing designs ; for a space -shiphaving a nose and tail would have to revolve

January, 1947 NEWNES PRACTICAL MECHANICS

in space at a point where the gravitationalpull of another planet began. Otherwise theship would lend on its tail or the passengerson their heads. There was the further objec-tion that there is no atmospheric layersurrounding the moon on which a wingedship could be airborne.

Spherical ShapeMr. Warnett Kennedy felt that the most

sensible shape for a space -ship, not limitedby considerations of streamlining, was thesphere. The earth, moon and other bodiesare spherical. Why not a space -shipdesigned as a " man-made planet " ?

The strongest shape provided by natureto withstand shock is an eggshell. Frointhe point of view of a constructionalengineer, therefore, he arrived at a sphericalconstruction having high strength -weightrtItio and a shape which could revolve inany direction, or, when equipped withatomic -powered motors, could move in anydirection. From this and other considera-tions the space -ship became more than afantasy of design.

" I do not claim that the space -ship isimmediately practicable, but I do regard itas an intelligent anticipation of the trendof future design," Mr. Kennedy says.

Transparent Outer ShellAt the " Britain Can Make It" Exhibition

Mr. Warnett Kennedy's model of the space-ship was seen hovering near the surface ofthe Moon. It appeared as an intricate con-struction, with rocket tubes and telescopes,surrounded by an outer transparent sphere.This outer shell, which may represent asurface sensitive to cosmic forces, can belikened to the invisible layers surroundingour own planet, protecting us from the outercosmic rays or reflecting radio rays.

The space -ship will have a central controlchamber where observers during a journeywill be able to study views of the earth,

135

Diagram showing a geodetic braced shell construction containing all equipment andliving compartments.

moon or planets by camera obscura methods. on the model: " Triplex " Safety Glass Co.,In connection with the space -ship exhibit Ltd. ; Dufay-Chromex, Ltd. ; I.C.I. Ltd.

the following firms carried out special work (Plastics Division).

British Planes for AmericaORDERS for too private, aircraft have

been received by Miles, Aircraft, ofReading, Berkshire, for dispatch to theUnited States, South Africa, Australia andFrance. The machine, claimed to be thesafest, light aeroplane in the world, is theGemini. Powered with two too h.p. CirrusMinor engines, this low -wing cabined mono-plane has seating accommodation for threepassengers and the pilot. Wooden construc-

(Above) The completed Gemini aircraft on theairfield ready for delivery after coming off the

asSembly lines.

(Left) A general view of some of the Geminiplanes on the production line at the Miles

Aircraft factory.

don is used throughout the airframe. Anadvanced method of plastic bonding makesthe aircraft impervious to moisture andsuitable for operation in any part of theworld. The photograph reproduced on theleft was taken at the. Miles Aircraft Factoryat Reading, where these 'planes are nowunder construction.

No.


THE WORLD OF MODELSThis is the Eighth Anniversary of theAdvent of our " Model Man " to

"Practical Mechanics," His First Illus-

trated Article Appearing in January,

1939. Many Happy Returns, " Motilus "

Lectures on Various CraftsTHE Education Authorities in various

parts of this country are now arrangingfor lectures by well-known personalities

connected with various crafts. These lecturesshow the application of such crafts as modelsto industry, history, the progress of transportby road, rail, sea and air, and our illustrationshows a display of models used with one ofthese lectures, given to a convention of schoolteachers at Leicester, the speaker beingMr. W. J. Bassett-Lowke, M.I.Loco.E. His

A three-quarter rear view of a lin. scale modeltraction engine made by Mr. H. Woodford,

of Chatham.subject was the connection between educationand the pursuit of a hobby, and he dealt withmodel work in all its phases, the progress ofbetter design and more scale appearance inboth models of railways and ships. Hementioned that this idea had not only grownup among amateur but also professionalmodel makers, and the inspection of themodels would influence boys in their apprecia-tion of good and accurate design in everydaythings.

Scale Model Traction EngineThe 1 -in. scale model traction engine

and castings, featured in pre-war days in thismagazine, the designs being by the editor,Mr. F. J. Camm, has been one of the mostpopular lines of this kind ever introduced bythe Northampton firm of Bassett-Lowke,Ltd. Many have been successfully builtand have taken prizes at exhibitions, and asilver plated model built from the standardcastings by Mr. F. J. Camm himself was

A display of models used with a lecture given toa convention of school teachers at Leicester.

exhibited at the recent " Model Engineer "Exhibition held at the Horticultural Hall,Westminster, the first post-war appearanceof this outstanding gathering of the modelfraternity.

This traction engine bids fair to be as popularto -day as it was in the days before the war,and our illustrations show a model recentlycompleted by Mr. H. Woodford,A.M.I.Mech.E., of Chatham, which wasawarded third prize in the General Enginesand Road Roller Section of an exhibition heldat the end of September by the MedwayModel and Experimental Engineering Society.

Although an engineer by profession, thisis the first model Mr. Woodford has made-an excellent effort, particularly when it isknown that he designed and constructedhis own gear -cutting attachment, as it was

Another view of Mr. Woodford's model tractionengine, showirk, the displacement lubricator.


not possible at the time to purchase finishedgears.

As Mr. Carom himself writes, " I thinkthis particular model has given me greaterpleasure in the making than any other, chieflybecause it calls for interesting work in severalbranches of model engineering, namely,marking out and drilling, fitting, boring,screw -cutting, silver soldering and boilermaking, turning and assembling." Thecylinder, eccentrics, -crankshaft, pressuregauge and other small fittings, which it wouldscarcely pay the model maker to constructhimself, are supplied in finished form, andit is good to know this model is on themarket again.

Model -Pumping StationI have seen many models of all types,

both professional and amateur, in manycountries, but. never before have I seen amodel of a sewage pumping station. Thismodel is the work- of Mr. -S. ' Charley, ofStrood, Rochester, who is in the rather uniqueposition of having built both the pumpingstation itself and the miniature.

In 1934,- during a discussion with one ofthe Surveyor's assistants regarding pumps,quite casually Mr. Charley said he wouldmake him a model pump to play with. Theassistant replied he would wager io Player'scigarettes that he couldn't. The bet wasclinched at 20 Player's for a model of thecomplete station !. This is Mr. Charley's story : " I boughta fin. model lathe, with foot motor and four -jaw chuck, and started making the model to1124 scale. Then I, wondered_ if I. could makean eleciric motor of that scale to be efficient,so I decided to scrap what I had made andstart off.again in 1/12 scale.

the modelthe small

wheels from an old brass band, such as isfitted to a steam tractor engine around itsboiler.

The other pumps and motors are madefrom wood true to scale and with the necessarydetail. The switchgear is of wood except suchdetail as isolated switches, which are inmetal.

The motor which first drove,the pump wasmade up from an old burnt -out motor, whichunfortunately got oiled up and burnt upagain, so I managed to find a burnt -out6v. windscreen motor and re -wound it,making the casing from a piece of waterpipe.

I had a lot of trouble in gettingto work automatically, owing tosize of float (true toscale) and the friction ofthe pulley gear, etc., but,eventually I succeededby making a zinc floatto which I soldered apiece of brass so as tobe able to reduce theweight in relation tothe counterweight,thereby working themercury dashpotswitch."

Here it ' might beadvisable to add a fewdetails of the realpumping station, whichserves the low-level areaof the south side ofRochester. .The sewageflows into the stationby gravitation into' thecircular tank, in thecentre of which is built

ation, showing the pumping gear.

the pump chamber, of reinforced concrete.The top portion of the building, or the motorroom, is built of engineering bricks.

When the sewage rises- to a predeterminedlevel, the pumps, consisting of three 6in.and one 8in. Blackstone unchokable pump,are put into operation by float -operatedswitchgear, thereby starting the inductionmotors through auto -transformed switch -boxes. The electric supply is 400v. 5o cycles.

The flow of sewage into the station isrecorded by a float -operated recorder andthe flow output by a Venturi meter placed inthe delivery pipe 'from the station. Eachsix - inch pump delivers r,000 g. p. m.

Rear view of the model pumping st

The working pump is made from old scrappieces of brass-the impeller, for _instance,consisting of the boss, shroud and vanes,all being separate pieces ' sweated ' together,and if I couldn't find a piece of brass largeenough I had to compromise by sweatingtogether a piece of round stock to a disc, suchas the gland box and pump casings.

The channels were made from tin cans,etc., being formed over a piece of squaremetal, and the plummcr block bearings weremade from the solid. Thrust races were made

-from mild steel washers and casehardened.Valves and pipe line were made from fin.

copper tube-the pipe flanges and valve

and each eight - inch pump r,2oo g. p. m.Returning to Mr. Charley's working

model, he says that the Venturi meter andlevel recorder are true to scale and with asmuch detail as possible, and the weeklycharts are removable.

All handrail stanchions are turned frombrass and the stairs made from pieces of tinsweated together. The building and tank aremade from plywood and are painted as in theoriginal. The brickwork was done by paintingin red, the bricks being represented byscribed lines correct as to bonding.

The model, which is Mr. Charley's first(" and I have smoked the cigarettes," headds ! ), measures in its case 5ft. 6in. by 4ft.6in., and took four years to -make at an average

A model pumping station, made by Mr. S.Charley, of Strood.

of four hours on four nights per week.

Post-war Model SuppliesI am afraid this festive season has not been

a particularly happy one for those who wereanticipating good supplies of models of alltypes, approaching pre-war conditions. Veryfew people realised the enormous stocks andvarieties of model goods that were held byleading manufacturers and dealers in thiscountry at the outbreak of war in 1939.Practically everything available was soldduring the shortage of the war period, and itwill take several years before the large rangeof goods of every description are back again.

A few of the leading manufacturers thisChristmas have been able to produce a limitednumber of productions. Messrs. Bassett-Lowke,Ltd., have brought out again theirset of ogul parts, one of their most popularpre-war lines, also some finished steamlocomotives in gauge " 0," and various typesof castings; also castings and parts and fittingsfor building the fin. scale " Flying Scotsman,"the Burrell Traction Engine, and generoussupplies of track materials. Messrs. Trix, Ltd.,despite their best efforts, were unable toproduce any of their famous " oo " gaugetrains, except for export, but I understandthere will be a steady flow as the New Yearproceeds. Many other model shops inLondon and elsewhere have recently showna decided improvement in the amount of goodsavailable, especially those connected withmodel aircraft and petrol engines.

May this New Year bring- us more settledconditions, -greater production, and moreconsumer goods for people who wish to buy.


GLUE has been used to our own knowledgefor over 3,500 years. There areexamples of Egyptian furniture showing

that the ancient craftsmen employed an animalglue of the same general characteristics as themodern adhesive compound so largely usedby all woodworkers and which we term glue.

Besides, the common carpenters' glue,which is an animal product, requires heatingwith water, and is a non -waterproof glue,there arc many adhesives of a similar nature,some made from fish offal, others fromstarches and casein. Silicate of soda (waterglass), in which we preserve eggs, is a formof glue used for paper objects. All of these

or Concave

Fig. I. Best edge for joining up to makewide boards (exaggerated).

products will be dealt with in the courseof these notes.

Carpenters' GlueThis animal glue is in its better qualities

made from the hides and hoofs of beastsslain for food, cheaper grades being obtainedfrom the bones. The stuff is akin to gelatine,but it is not strictly correct to say that thelatter is simply a more refined and purerkind of glue, although the origin of the twosubstances is the same.

Carpenters' glue is always used in a heatedcondition, and it may be said that wheneverthis glue is heated while dissolved in water,a chemical action occurs. Therefore, if theheating be repeated, the strength quality ofthe product is adversely affected. Theheating is not simply a process of making theglue soft ; something else is happening. Forwoodwork a high grade glue is the mosteconomical, but in making a choice it isnot necessary to specify the pure " hideglue " ; such glues are strong, but are alittle like Blass, and prone to break on impact.A weaker but more elastic quality is to bepreferred.

Testing a Sample of GlueA glue which smells badly should not be

used. It is most probably partly decomposedthrough not being made from carefullycleansed raw materials. Further, thiscleansing process in the manufacture of glueis important, as all grease should be removed.In Government tests of glue the surface of adissolved sample is examined for the presenceof grease. It is also notable that glues whichare alkaline are more likely to decomposethan samples which on a litmus paper test areshown to be slightly acid. This is due tobacterial activities. Therefore, a glue shouldnot readily go mouldy in a damp atmosphere,as this indicates that it has been adulteratedwith sugar or molasses. Sour glues are alsoto be avoided, and while a high gloss on thesurface is not an indication of the highestquality, a uniform colour and uniform surfaceare desirable factors.

In breaking a sample between the fingersand thumb, an even and easy fracture suggestsa low strength and brittleness, but if thesheet ben& considerably before breakingand does so with a splintery edge, then it is aglue to be chosen.

Glues, Cements, and Adhesives -1Woodwork Glues and Gluing Processes

several occasions I have experienced diffi-culties in applying glue to woodwork in myout-of-doors workshop in the depth ofwinter. In spite of warming up the job bydabbing it with hot water, I have finally hadto take the work indoors into the warm kitchento finish it off in a satisfactory manner.These difficulties are more acute where thejob necessitates a certain time being spent oncramping up the joints in their properpositions after the hot glue is applied. If thesurroundings are so cold that the glue gaesinto a jelly before the parts are joined up, thenit is time to seek some other place to do thejob.

For woods with an even grain the bestfinish preparatory to gluing up is thatobtained by glasspaper following the useof the plane. In the case of materials likeoak, chestnut and oregon pine, which have anatural structure of a mixed hardness, agrain with hard veins in a wood of softercharacter, it is best to leave the surface asit comes from the steel tool. The use ofglasspaper is apt to leave the surface uneven.It removes the softer portion leaving thehard grain standing up, and a perfectlyflat contact, which is an essential to a goodglue joint, is not obtained.

By " HANDYMAN "

There are many tests and testing machinesfor glues and glued joints, but they are notaltogether satisfactory, and if the readeradopts them it is wise to take the average ofmany trials rather than to rely on any singletest.

If when a sample of melted glue is rapidlystirred a foam appears on its surface, then itsquality is not good. This test may best beperformed with an egg -whisk. Good gluesshould absorb six times their own weight ofwater and still remain in a jelly form.

Contact_

Bad Contacr

Fig. 2.-A wavy edge to be avoided(exaggerated).

Making the GlueThe old idea that glue to be any good

must be " cooked " for one to three hourshas been exploded by scientific researchesinto the nature of animal glues. The sameapplies to the long soaking of the cakesbefore placing in the heating pot, so oftenrecommended. The glue should be brokenup into small lumps and placed in not morethan five times its own bulk of clean water,about three or four hours before it is necessaryto use it.

Clued Pressed Down

Rubbed to and fro for 41--tew moments unit/ all

------ Surplus C/ue Exudes ---

ViceBench

Fig. 3.-Rubb'ng the glued joints together.

Soaking GlueThe soaking of glue too much in advance

of its use is liable to start putrefaction.Perfectly clean water-certainly not t h ewater out of the iron receptacle which inthe ordinary appliance surrounds the gluepot-is essential to success. Any waterwhich contains iron or lime in excess seriouslyinjures glues. It has been estimated bylaboratory tests that impure water will reducethe value of a glue by one half.

Glue should always be heated in such away that it never gets hotter than 15o deg. F. ;therefore, to put the glue on a gas stove is toabsolutely spoil it. The above temperatureis below the boiling point of water, but foramateur purposes an earthenware jam jarcontaining the glue standing in an open sauce-pan of water will not rise much above therequired temperature if the heating water isallowed to simmer quietly on a stove or fire.

Using GlueThe operation of " gluing up " should

always be performed in a warm room. On

Jointing WoodAs wide boards are difficult to obtain, and

in any case are very expensive, woodworkersresort to the glue jointing up of narrowerpieces of stuff. It is very important that suchwork should be well done, otherwise theopening of joints may spoil the appearanceand usefulness of the finished article. If welldone the glue joint of this kind is as strong asthe natural wood.

Jointing Up to Make Wide BoardsIn jointing a long board, the ideal edge is a

slightly hollow one, as indicated in thesketch, Fig. I. Cramps of the usual kind willthen pull up the joint quite tightly.

Under no circumstances should the " shoot-ing " of the edges of the boards be done socarelessly that a wavy line is produced asshown in an exaggerated manner in thesketch of the two adjacent pieces (Fig. 2).No amount of cramping will result in thedesired perfect end -to -end contact.

The board, should not be dead cold, andwith one in the vice, as indicated in Fig. 3,the glue should be applied thinly over thesurfaces to be joined. The two parts shouldthen be placed together and the upper onerubbed into the lower one, all surplus glueexuding in the process. All this mustbe done quickly, so that the job is got betweenthe cramps before the glue gets into thesemi -set or jelly state.

SS

Fig. 4.-Bench wedge cramps.


A Substitute for Carpenters' CrampsWhere carpenters' cramps are not available

and the job is too big to get between thejaws of the bench vice, a good idea is to make

A series of wedges on the flat of the bench.One board is made to rest up against a stopstrip (SS Fig. 4) nailed to the bench, and atthe other side two or more backing strips(BS) (according to the length of the job)are nailed down at an angle with a gapintervening. Wedges (W) are then driven in,as shown in the sketch.

All this must be prepared before the glueis applied so that there is no loss of time

between the application of the glue and thefinal fixing up in the cramping device.

The power of a wedge when hammered intoplace is enormous, and, therefore, the backingstrips (BS) must be firmly nailed or screweddown to the bench. If there is any dangerof the board cockling in the wedging processmeans must be employed to keep the jobflat.

White GlueIn stopping up a bad place or knot -hole

in a plank too small to be filled by a woodenplug, and which has to be finished off ina natural manner, carpenters often resort

to a readily made mixture of sawdust,whitening and hot glue. There is no objectionto this mixture, except that zinc oxide inmoderation is a better " whitener," havingno deleterious effect on the strength of theglue. For a really white glue, which may benecessary in some cases, use a mixture ofroughly one of zinc oxide to four of meltedglue. This can be kept in a separate pot andcan be re -heated as occasion may require,always remembering that even ordinary gluecannot be re -heated indefinitely withoutsuffering in its strength quality.

(To be continued.)

Letters from ReadersBack Issues : An ApologySIR, With reference to my offer of old

copies Of PRACTICAL MECHANICS pub-lished in the November issue, you will beinterested to know that I have had over90 requests.

I have given first priority to requests forindividual copies (I know the disappointmentof missing one article of a series). Theremainder I have done up in parcels of12 each and shared them among the firstapplicants.

I am replying individually to all readersenclosing a prepaid envelope, but shouldbe grateful if you could spare a corner toinsert this apology on my behalf for notreplying to all the other applicants ; thespirit is willing but the cash is short.-L. A. LEADBEATTER (London, S.W.). Push -Bar

SwitchRegister of Model Engineering SocietiesSIR,-During the Model Engineer Exhi-

bition, many visitors called at theS.M.E.E. Stand and at other club standsto inquire for the address of their nearestclub. In some cases, we were able to givethis information ; in other cases, we unfor-tunately had not the information available.

It was therefore suggested to me by Mr.Bontor, of the Malden Society, that it wouldbe a desirable thing to compile a register ofModel Engineering Societies. One of ourmembers, Mr. L. J. Parish, of 27, ColeridgeWalk, Hampstead Garden Suburb, N.W.H,has very generously undertaken to do thenecessary clerical work in compiling such aregister. The idea is that should the clubssupport this scheme and send particulars toMr. Parish, the register of clubs would beprepared, printed or duplicated, and copiessent to all the clubs concerned. It is feltthat provided all clubs co-operate, the costto each individual club would be trivial,and the value of the register would bevery great.

I would, therefore, appeal for all clubswho wish to be included in this register tosend Mr. Parish, at the above address, par-ticulars of their club as follows :

Name of club and secretary's address.Time and place of regular meetings.Speciality of club, if any, e.g., locomotives,

ships or general.Situation of any special facility, e.g.,

workshop, sailing water, track.I think it will be agreed that it is desirable

to have standard particulars for each clubin order to simplify Mr. Parish's work, andI feel that these particulars do give theinformation which a prospective memberwould wish to have of a club he was thinkingof joining.-T. W. PimiocK, chairman,Society of Model and Experimental Engineers(28, Bolton Street, Picadillv, London,W . ).

III]

Rotary SanderSIR, - Following the publication in

PRACTICAL MECHANICS Of designs foramateur made spray -gun equipment, itoccurred to me that the preparation of thesurface to be sprayed is equally important.This can best be carried out by the use of asander, and as these are somewhat expensive,the details of the one I have constructedand have in constant use may be of help toother readers.

This is based upon the motor unit from an" Electrolux " type vacuum cleaner, whichincorporates a pistol grip and switch, theforward handle being constructed from lin.

Fuse WiresIR,-Further to your reply under Queries

and Enquiries, to R. J. Barber, in theNovember issue Of PRACTICAL MECHANICS, Iwould point out that for all normal types ofcables the rating stated by the regulationsfor the electrical equipment of buildingsissued by The Institute of Electrical Engineers(eleventh edition), together with 1946 altera-tions, is 5 amps. for both 1/.044 and 3/.029cable. Therefore, for both sizes, the correctsize of fuse should be 35 S.W.G. tinnedcopper fuse wire, or 21 S.W.G. standardalloy of 63 per cent. tin and 37 per cent.lead.

As you will agree, the overloading ofcables is a very bad practice owing to thedanger of overheating, and the subsequentliability of fire.-F. G. SOUTHWORTH (Holy -well).

Inlet Valve. Motor Una. From Threaded

Vacuum Cleaner 4 a f:Hand Dr/I/ Chuck

Drilled TappedB.S.F.

ills IIWllllllgllllllllllllllillllillllilllllllllilllllllll

.410

4 -Conduit Split toForm Front Handle

Cup Washer!

Thin Leather

41Felt

A motor -driven rotary sander (S. Madders)

diameter electrical conduit sawn lengthwiseand bent to the shape of a catapult, the splitarm being drilled to go under the motorassembly bolts. A " Shockstop " cycle gripis fitted to the handle part, a drill chuckfrom a hand -drill is tightened on to themotor shaft, and the chuck spindle is drilledand tapped lin. B.S.F. to take the shank ofan Austin Seven inlet valve shortened andthreaded to suit. Upon this is assembled acountersunk washer as used for adjustingcar headlamps ; this is to enable the valvehead to be pulled down flush with the faceof the backing disc, which is min. diameterand tin. thick, with packing felt faced withthin leather and stitched. The valve headwill be found to be slotted to take a coinfor tightening, and it is essential that thevalve head be pulled down at least flush withthe face of the sander disc, otherwise the workwill be marked. Suitable discs may beobtained from motor and paint factors.It is important that three -core flex be usedto connect up the tool, using one lead forearthing the tool.

The accompanying sketch will, I think,make the construction clear.-S. MADDERS(Blackpool).

THE BRITISH INTER-PLANETARY SOCIETYTHE lecture programme of

the above society, forthe session 1947, is as set outbelow. All meetings will beconvened at 6.o p.m. precisely,at St. Martin's TechnicalSchool, Charing Cross Road,London, W.C.2. Visitors areallowed at meetings of thesociety, but it is requestedthat they first write to theSecretary, I, Albermarle Street,Piccadilly, London, W.1, toobtain permission if they arenot introduced by a member ofthe society.

Saturday, ,7anuary 4th, 5947" The Energy and Stability

of Atomic Nuclei," by L. R.Shepherd, B.Sc., a Fellow of the society.Mr. Shepherd took his B.Sc. at the Universityof London.

Saturday, February ist, 1947" Interplanetary Flight : Is the Rocket the

Only Answer ? " by A. V. Cleaver, a Fellowof the society. Mr. Clever was, till recently,the chief project engineer of de Havilland Co.,Ltd. (Airscrews), and is now engaged onproject work with the D.H. Engine Company.

Saturday, March 1st, 1947" Recent Developments in Rocket Design,"

being a technical survey of the latest develop-ments which can be published, the results ofinvestigations of German war rockets andother modern work. Lecturer to be arrangedlater.

Saturday, April 12th, 1947 (at the ScienceMuseum, South Kensington)" Cosmic Rays," by Lionel Gilbert,

A.R.C.S., B.Sc., a Fellow of the society.The lecture is an introduction to the studyand peculiarities of cosmic rays, using equip-ment available for demonstration at theScience Museum.


'QUERIESENQUIRIES

A stamped addressed envelope, three pennystamps, and the query coupon from the currentissue, which appears on back of cover, must beenclosed with every letter containing a query.Every query and drawing which is sent mustbear the name and address of the reader.Send your queries to the Editor, PRACTICALMECHANICS. Geo. Newnes, Ltd., Tower House,

Southampton Street, Strand, London, W.C.2.

Chromium PlatingWILL you please give me details of how bright,

non -tarnishing plating is put on to thebrass clock and snatch gear wheels and plates ?If this is done electrically, for your informationI am on 230 volts A.G. and have a fairly wellequipped workshop.-A. Mullineux (Onchan,I. of M.)."BRIGHT, non -tarnishing plating " means nothing

from a descriptive point of view. Platings ofgold, rhodium, platinum, chromium are all brightand non -tarnishing.

Whilst, for some purposes, clock wheels and pinionsare sometimes plated with palladium, we must assumethat you refer to chromium plating.

Now, chromium plating is a difficult job, and youare not likely to be very successful at it if you are abeginner. The plating solution is made up on thefollowing lines :

Chromic acid .. 250 grams.Sulphuric acid .. 2.5 grams.Water .. I litre (u,000 ccs.).A high amperage direct current is needed, a current

of the order of too amps per square foot of surface tobe plated. Use a stainless sheet steel for the anode(positive electrode) and employ a glass tank for con-taining the solution. If stainless steel cannot be obtained,use a strip of lead. The temperature of the solutionshould be maintained between 40 deg. and so deg. C.

We would advise you to study a good introductorytextbook on electroplating, such as Messrs. Field andWeill's " Electroplating (Pitman, 15s. net), whichyou might possibly be able to obtain second-handfrom Messrs. W. & G. Foyle, Ltd., Charing CrossRoad, London, W.C. It is, however, almost hopeless

, to attempt chromium plating without having at leastexperience in some other branches of electricaldeposition.

Waterproofing ProcessesT HAVE recently purchased an ex-R.A.F. " buoy-

ant " type flying -suit, which I use for motor-cycling, and I find that it is not waterproof. Ittakes some time for the material (of which Ienclose a sample) to become saturated and as ithas a non -detachable kapok lining, it takes along time to dry out.

Could you please supply me with a formulato make a suitable waterproofing solution orinform me of a proprietary material to make itthoroughly waterproof ?-R. L. Bell (Croydon),IT is a most difficult job effectively to waterproof

a made-up garment such as the one you refer to.Published books of formulas and recipes abound informulas for the making of waterproofing agents, butthey are mostly of little use when put to any severepractical test.

The specimen of fabric which you submitted is of afairly fine double weave, and it would best be water-proofed by some process of rubberising or, alternatively,treated with a drying oil so as to produce a sort of " oil-skin " effect. Neither of these treatments can very wellbe carried out by you individually since they needspecial plant and cannot be imitated on the smallscale.

It is possible, however, that you might be able topersuade a good firm of waterproofers to undertakethe job for you.

Two such firms are : Messrs. J. Nandleburg and Co.,Ltd., Pendleton, Salford, 6, Lancs ; The Greengateand Irwell Rubber Co., Ltd., Greengate Works,Salford, 6, Lancs.

However, if you wish to attempt a waterproofingprocess yourself, three types of process are as under :

(I) Immerse the fabric for to -15 minutes in the follow-ing solution :

Glue or gelatine .. 5 parts (by weight).Water 95 parts (by weight).

Wring out the fabric, but do not rinse. Then let itdry in the air and without heat. After this, immersethe treated fabric in a solution made by mixing t partof commercial formalin solution and 4 or 5 parts of

"water. A five minutes' immersion in the diluted formalinsolution will be sufficient, after which the fabric shouldagain be allowed to air-dry without heat.

In this process, the glue or gelatine impregnates thefibres of the fabric and the formalin renders the absorbedglue or gelatine absolutely insoluble and therefore waterresistant.

(2) Dissolve half a pound of beeswax in t gallonturpentine or a mixture of turps and white spirit.

Rub this sparingly into the cloth, and, if possible ironit in with a warm (not hot) iron.

(3) Make up the following mixture :Raw linseed oil .. a gallon.Beeswax .. t3 oz.White lead .. a lb.Resin (pale) .. 12 0z.

Heatthe above with continual stirring until themixture almost boils. Then apply it (sparingly)warm to the upper side of the fabric, wetting the underside of the fabric with a wet sponge immediptelybefore applying the hot mixture to the upper side.

There are no proprietary waterproofing solutions fortextile use.

Windings for Small MotorHAVE recently obtained some laminationswith a view to constructing a small motor for

driving a sewing machine. Could you tell mefrom pattern enclosed :

(a) Size of wire and number of turns to windthis with ; also coil span to adopt ?

(b) What will be maximum h.p. obtainable forthis size of motor on a supply of 23o volts A.C. ?

(c) Size of commutator ?(d) What size and type of wire should I use to

make a variable resistance to control the speedof the motor from full speed to zero ?-C. Pearson(Brodsworth).WE consider the stampings should be suitable for the

construction of a motor of about A h.p. Wesuggest you wind each field coil with 190 turns of25 s.w.g. S.S.C. enamelled, or good quality enamelled,wire, the two coils being connected in series with each

Stator Length 2 a.

*574

Rotor Length 2i'

i5" Length

--Widen atTop .51*

Width asBottom .z

Overhaul dia. 24Air Cap 14 Thous..411 Round.

Field lamination, and details of armature for asmall electric motor.-(C. Pearson.)

other, so as to create poles of opposite magnetic polarity,and in series with the armature.

Assuming the armature has 15 slots and is to be usedwith a 3o segment commutator, this could have 15 coils,each with too turns of 3o s.w.g. S.S.C. enamelled wire,a loop being brought out from the centre of each coilfor connecting to the commutator. A coil span fromslots a to 8, etc., would be suitable.

With the armature placed so that slots r and 8 areequidistant from the centre of one pole -face, number thecommutator segment which then lies under the nearestbrush, number 2. All numbering is considered clock-wise at the commutator end. For clockwise rotationat the commutator end connect the start of the coil inslots t and 8 to segment 3, the loop to 4, and finish ofthe coil to segment 5. Connect the start of the coil in

slots z and 9 to segment 5, loop to 6, finish of the coil tosegment 7, and so on. For counter -clockwise rotationsubtract 4 from the numbers of the segments quotedabove for the coil connections. The 3o segmentcommutator could be about Oin. diameter on theworking face, this face being about )in. long.

A resistance which would probably give you all thespeed control required could be made from zoyd. of32 s.w.g. Brightray resistance wire, as supplied byMessrs. Henry Wiggin & Co., Ltd., of GrosvenorHouse, Park Lane, W.r, although a longer resistancewould be necessary to reduce to crawling speed on lightload.

Removing Ink Stains on WoodCAN you give me some help with the following

difficulty ? I have recently acquired an oak -topped table which has been so badly stained thatI think the top surface must be planed over toremove most of them. There is one, however, ofink which may have sunk deeply into the wood.What do you advise me to do ? Is there anybleaching agent which would remove the inkwithout damaging the wood too much ?-R. F. Mellor (Oxford).WE think that you will find the ink stain to be

removed entirely by a simple planing of the woocof your table -top. Aqueous liquids do not penetratewood to any great extent, so that a very little planingof the wood should remove the offending stain.

You do not tell us what type of ink stain is presenton the wood. If the stain is of a carbon (Indian) ink.no amount of chemical treatment will remove it. Mostmodern writing inks, however, are very fugitive andinferior creations so far as actual fastness is concerned.You will therefore be able to remove the stain byrubbing a paste of chloride of lime and water over thestain and then acidifying the paste with a little diluteacetic acid. The same direction applies to theremoval of stains caused by the older iron inks. For thelatter, also, you may use a strong solution of oxalicacid (Schedule I poison) used hot. Modern ink stainswill also be removed by " Milton " wiped over them,and then acidified with acetic or hydrochloric acid(dilute).

Blueing Solution for Gun Barrelj HAVE an old shot -gun with a barrel ofA Damascus steel from which the protective" blueing " has worn off. Can you tell me how thiscan be restored without using proprietary prepara-tions ? I have access to a chemistry laboratory.-M. M. Legge (Omdurman, Sudan).

gun barrel must first of all be most thoroughlycleaned and degreased by washing with a hot soda

solution. It is then rinsed, dried and polished withfine sandpaper and finally with rouge.

The following blueing solution is now made up :Mercuric chloride .. 4 parts (by weight)Potassium chlorate .. 3 parts (by weight)Alcohol (rect. spirit) .. 8 parts (by weight)Water .. 85 parts (by weight)

This solution must be made up and used in a non-metallic vessel.

Swab boiling water over the gun barrel until it attainsthe temperature of the water. Then dry the barrelquickly with a clean cloth and at once swab it over withthe hot blueing solution.

The process can be repeated two or three times untilthe exact shade required is obtained. Polish the barrellightly between the blueing coats in order to remove anyimperfections.

After the final application and while the gun barrel isstill hot, apply a thin coat of boiled linseed oil to thebarrel with a cloth. The final blue -black finish thusobtained will vary somewhat with the type of steel usedfor the making of the barrel.

Remember, also, that the mercuric chloride used inthe above formula is a powerful poison.

Treating Plaster CastsT HAVE produced some plaster -cast figures,A and require to finish them in a cream colourto give a wax -like effect. Can you inform me of amethod of doing this ?-A. J. France (Reading).FIRST of all, obtain a quantity of ordinary cooking

gelatine. (Ordinary glue will do also, but gelatineis cleaner and better to handle.) Dissolve 5 parts ofgelatine (by weight) in 95 parts of water. This willform a clear solution which will set to a jelly whencold. If this gelatine solution is to be kept for any

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length of time, you must add a few drops of carbolicacid to it to prevent it from becoming mouldy.

Warm the gelatine solution and then either immerseyour plaster articles in the warm solution or brush thesolution on to them. When the plaster has absorbedas much of the solution as possible, allow it to drain andwipe it over with a clean cloth. Then put it away to dry.

Obtain from your local druggist or pharmacist a smallamount of commercial formalin solution. Mix t partof this solution with 4 parts of water and apply theresulting diluted formalin solution with a brush to thegelatine -treated plaster articles. Then allow the plasterarticles to dry again.

By this treatment, gelatine will be absorbed by thepores of the plaster, thereby strengthening the latter,and the formalin treatment will render the gelatinequite insoluble in water, hardening it also. When theplaster articles have finally dried after the formalintreatment, you can apply any type of cream paint tothem so as to give the precise effect which you desire.Alternatively, you could give your plaster articles acoating of a good wax polish, which would give theman " eggshell," semi -lustre finish.

Luminous PaintWILL you please inform me if it is possible

to make luminous paint at home, and, if so,what ingredients are necessary and in whatproportion ?

Also, are there any other colours of luminous,paint except green, and, if so, how are theyobtained ?-P. Jordan (Portadown).IF you can obtain the necessary luminous ingredient,

it will be quite a simple matter for you to make upa quantity of luminous paint. The preparation ofthe luminous ingredient, however, is difficult, andapplied on the home scale, it is very unreliable. However,the method is as follows :

Take t part of gypsum or plaster of Paris and mix itintimately with 4 parts of charcoal. Dissolve in a littlewater one or two crystals of zinc sulphate and add thisto the mixture. Also add a pinch of manganese dioxide.The mixture is then placed in a tin and heated to brightredness in a hot fire. The heating is continued as longas (but not after) any charcoal remains. The creamy -coloured residue (impure calcium sulphide) is thenexposed to bright light, and if the preparation has beensuccessful (which is often not the case) it willluminesce, in which case it is ground up finely andincorporated into clear oil or cellulose varnish in orderto make the luminous paint.

It is better to purchase luminous calcium sulphidefrom a firm of laboratory chemical suppliers, such asMessrs. Bair & Tatlock (London), Ltd., 14-17, St.Cross Street, London, E.C.1, or Messrs. A. Gallenkamp& Co., Ltd., Sun Street, Finsbury Square, London,E.C.2. This costs about 2s. 6d. per ounce and gives agreenish luminescence. Luminous zinc sulphideprovides a bluer light. This costs about 12s. 6d. perounce.

You should note that these luminous materials needperiodic exposure to strong light for their reactivation.Only luminous substances containing radio -activematerials, such as radium barium bromide, arepermanently luminous and do not require periodicalreactivation by exposure to strong light. Suchpermanently luminous materials are, however, exceed-ingly expensive.

Bleaching Wooden Furniture : Parchmen-tzstng Paper

CAN you advise me on how to bleach woodenfurniture ? The simpler the method the

better as it would have to be done at home.Also, can you give me particulars of a method

whereby good white cartridge paper may betreated to give a result like parchment ?-F. W.Wallace (Wickford).FIRST remove all the paint, varnish, or lacquer

from the woodwork, either by scraping, bywashing down with caustic soda or soda ash solutionor by making use of one of the commercial paintstrippers. Give the surface of the wood a good washingdown with soap and water, and then apply to it apaste made of water and chloride of lime. When thisis semi -dry, brush onto the pasted surface a dilutesolution of hydrochloric acid (spirit of salts)-sayone part of the acid to four of water. Effervescence willoccur and chlorine gas will be liberated. When theaction stops, wait for five or ten minutes, and thenwash away all the white residue. '

The process can be repeated, if necessary. It iseffective, but, of course, results in the roughening ofthe surface of the wood, so that glass -papering isafterwards required. The wetted wood should after-wards be allowed to dry out completely without heat,otherwise some degree of warping and/or twistingmay occur.

To parchmentise white paper of the cartridge type,make up a bath consisting of pure sulphuric acid ofexactly 77 per cent. strength. This strength of acidhas a specific gravity of 1.7. Immerse the paper in theacid for exactly to seconds and at a temperature of notmore than 17 deg. C. Well wash the paper afterwardsand then allow it to dry without heat.

An alternative, and better, method is to use asolution containing equal parts of calcium chloride andcalcium thiocyanate, the solution having a boiling -pointof 155-157 deg. C. The parchmentising action of thissolution is completed within about 3o seconds, but thepaper may be left in the solution for a longer periodwithout injury. Calcium thiocyanate (calciumsulphocyanide) used to be a commercial product, butwe doubt whether its manufacture has yet recom-menced. If you are interested in this question writeto the Manchester Oxide Co., Ltd., Miles Platting,Manchester.

Electrified FencePLEASE advise me how to construct an electric

fence energiser (either for battery or mains)which will be sufficiently powerful to containhorses, but be harmless to human beings.-E. M. R. Frazer (Burton -on -Trent).WE suggest you feed the fence through a small

induction coil, which may be constructed asfollows : The core could be made of annealed softiron wires of 2o s.w.g. Sin. long, the wires beingbound with fine wire and soldered together at theends. The primary winding may consist of four layersof 22 s.w.g. D.S.C. or D.C.C. wire ; and the secondaryglb. of 36 s.w.g. D.S.C. Each layer of the secondaryshould be basted with hot paraffin wax after winding on.

One end of the core should be squared off to operatethe contact make and break to be connected in theprimary circuit. This could consist of a piece ofsoft iron gin. in diameter by tin. thick, mountedon a strip of German silver or brass about Sin. longby gin. wide. The strip should have a tungstencontact to correspond with a fixed contact to befitted in the end of an adjusting screw. One endof the secondary and of the primary should beconnected to earth and the other end of the secondaryconnected to the fence. The primary should be fedfrom a 4 volt accumulator with the contact breakeradjusted to operate slowly.

The earth wire should be not less than 0.0045 squareinch in cross sectional area and connected to a rod,tube, strip, or plate, having a contact area of not lessthan t sq. it., which is buried to a mean depth ofnot less than 2ft. If the fence is installed in a positionwhere members of the public may reasonably beexpected to touch it, signs should be fitted on theposts at intervals of not exceeding too yards. Thesesigns may be metal plates or wooden boards not lessthan 8in. by din., painted with the words " ElectricFence " in black letters not less than tin. high on ared background.

Electric Flash Light .

(WING to deafness I cannot hear the door -bell,or anyone knock, unless very loud.

Could you please tell me if it is possible to installsome form of electric flash light that wouldflash for a few seconds after the door -bell waspressed ?-F. Newman (Leeds).YOU could no doubt meet your requirements by

using two electric -bell movements, and a controldisc driven through speed reduction gearing by a small

MIRROR -SILVERING is a difficult operation,and unless you have skill and experience in the

matter we would advise you not to think lightly of it.In the first place, the mirror must be made scrupu-

lously clean. After the old silvering has been rubbedaway the mirror must be rubbed with a solution ofcaustic soda. Then it is well rinsed in fresh water.It is then rubbed over with dilute nitric acid (one infour), again washed in water, which latter, this time,should be distilled water. Finally (and immediatelybefore silvering) a to per cent. solution of tin chloride(stannous chloride) should be flowed over it. 'Thissolution is then drained from the mirror, and the silver-ing solution is poured evenly over it. :silvering takesplace at once and is completed within three or fourminutes. The mirror is then gently rinsed in distilledwater and allowed to dry slowly.

Silvering solutions are of many types, each havingsome particular advantage. The following one is as goodas any for average work :

SolutionSilver nitrate .. .. I partDistilled water.. .. so parts

ftembie CoorectCircuit diagram for a flash light for use with a

motor. The connections of one of the bell movementsshould be altered as shown in the diagram so thatthis will act as a relay ; the two bell movements andthe small motor should be connected in parallel. Thecontact or control disc could have equidistant pro-jections at the edges or could be fitted with screws, theheads of which project from the face of the disc atregular intervals. The lamp should be connected to aflexible contact which touches the projections or screwheads as they pass it. A pin or cam should be fittedat the bhck of the disc to control the contacts C.

On pressing the bell push contacts A the motor isswitched on and the bell rings. At the same time therelay toil is energised and cleises the contacts B ; thesecontacts will maintain the bell, motor, and relay coilcircuits closed after the push-button has been released,until the disc has completed one revolution and hasthen opened the contacts C to de -energise the wholecircuit. The contacts C may need a little adjusting toget them correct ; the disc must move far enough toallow these contacts to close again during the periodthe push-button is pressed. In order to ensure this itmay be an advantage to fit a small flywheel on the motorshaft so that after the motor has been switched off bythe contacts B it runs on a little so that disc allows Cto close again.

Re -silvering a Mirror : Luminous PaintI SHOULD be glad if you would give me advice

on the following subjects :(a) Details of how to re -silver a mirror, with

formula for the " silver," etc.(2) A recipe for luminous paint. It is required

for a dark cupboard to indicate the position ofmeters, etc.-T. N. Hillyard (Iver).

Solution 2Caustic potash..Distilled water..

.. I part

.. to parts

Solution 3Glucose.. 1- partDistilled water.. .. to parts

To prepare the active silvering solution (which mustbe made up immediately before use) take a sufficientquantity of solution I and add ammonia to it, drop bydrop, with constant stirring until the precipitate whichis first formed just (but only just) redissolves. An equalbulk of solution 2 is now added, and the precipitatewhich is formed is again dissolved in the same waywith ammonia. To the mixed solution a very littlesolution t is added, just sufficient in amount (a fewdrops only) to produce a slight turbidity in the liquid.The solution is then mixed with an equal quantity ofsolution 3, stirred rapidly, and then poured over theprepared glass for silvering.

(2) The only luminous paint which will suit yourneeds (i.e., for use in permanent darkness) is onecontaining radium barium bromide. This can (or could)be obtained in small amounts from Messrs. Hopkinand Williams, Ltd., 16-17, St. Cross Street, London,E.C.I. Any other type of luminous paint which youmay use would have to be periodically reactivated byexposure to bright light. Such paint may be made by

grinding luminous zincsulphide (obtainablefrom above address) intoan oil or cellulose varnish(preferably the latter).

door-bell.-(F. Newman.)when dry.

Can you please give me a formula that willenable me to produce satisfactory chalks (whiteand coloured) ?-J. Cassar (Sliema, Malta).TF you add a very little alum or gelatine solution toA. your plaster -of -Paris mixture, it will very consider-ably delay the setting -time of the plaster, so that thelatter will then be able to be manipulated as you desire.

Any of your mixtures will be suitable provided thatyou mix them with a little glue water, which will serveto bind them together.

A suitable mixture is the following :Chalk or whiting .. 85 per cent.Pigment .. soWeak glue solution .. 5 -

The pigment is mixed intimately with the white chalk.The weak glue solution is added and the whole massis kneaded to a putty -like consistency. In commercialinstallations, the mass is often pressed hydraulically,but it can be moulded in smooth -walled steel moulds.

The necessary materials can be obtained from anychemical merchant, as, for example, Messrs, Baird &Tatlock (London), Ltd., 14-17, St. Cross Street,Hatton Garden, London, E.C.t, or Messrs. A.Gallenkamp & Co., Ltd., 57-29, Sun Street, FinsburySquare, London, E.C.2.

Moulds of various sizes can be obtained from :Pneumatic Engineering Appliances Co. Ltd., 3,

Central Buildings, Westminster, London,Messrs. John Macdonald & Son, Ltd., Nitshill, nr.

Glasgow.Messrs. Fox & Offord, Ltd., 181-187, Alma Street,

Birmingham.It may, however, be possible for you to utilise

locally -made wooden moulds.

Making ColouredChalksHAVE been experi-menting' with

plaster of Paris andwhiting trying to pro-duce what areordinarily known aswhite and colouredschool chalks. i find,however, that plasterof Paris when mixedwith water to theconsistency of" dough " sets almostimmediately, and doesnot allow enough timefor the material to beshaped into " sticks."

Whiting, althoughtaking longer to set,is too fragile and doesnot keep together


ELECTRADIXMAHOGANY CANVAS COVEREDMARK III CABINETS. x I2in. x7iin., with hinged lid and carrying handle,151- each. These are exceptionally wellmade, Sin. mahog. ; will strip and polish.SWITCHES. Dewar Panel Switches,8 -way, C.O., as new, 51- each. Yaxleytype 3 -pole 3 -way, 3/6 each ; I pole 8 -way,316. .

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in., mode! finish, ball bearings, etc.,take I!, amps only from your accumulator,751-.

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CONSTRUCTORS' PARTS FORYOUR OWN SET UP !

WALL TELEPHONE SETSBracket Mike, vertical or horizontal... 101 -

Transformer and Condenser for same 5/ -

Magneto Bell fitted ... 51 -

Switch hook and contacts 216Walnut Cabinet, Bin. x 6in. x 3in.,

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January, 1947 THE CYCLIST 25

VOL. XV

Editor : F. J. CAMM

JANUARY, 1947 No. 299

Comments of the Month.

All letters should be addressed tothe Editor, "THE CYCLIST,"George Newnes, Ltd., Tewer House,Southampton Street, Strand, London,

W.C.2.Phone : Temple Bar 4363

Telegrams : Newnes, Rand, London

Memorandum on ObstructionTHE Roadfarers' Club has recently

sent to the Ministry of Transport,the Home Office, and the Press, a

copy of its Memorandum on Obstruction.The congestion of the roads, which has

steadily increased since the end of the war,presents serious problems to road users andto commerce, and the Roadfarers' Club inits memorandum analyses the causes andsuggests remedies.

It points out that obstruction on thehighway is not a new problem introducedby the motor car alone, for the HighwayAct of 1835 made provision against obstruc-tion. All road users are effected by trafficcongestion, and although the memorandumchiefly deals with the matter from the pointof view of the motorist, it is of importance toall road users.

Here are the main points of thememorandum :

I.-Everyone is agreed that in cities andbusy towns there is severe congestion of thehighways. Presumably, when the Road Fundwas established in 192o, and the assurancewas given by Lloyd George that this Fundwas to be used for no other purpose than forthe making of new roads, the repair of oldones, and for the creation of adequate parkingplaces, it was realised that the rapid growthof the motor car industry would create aproblem which it was the duty of the Stateto solve.

2.-Since that time the Road Fund hasbeen used as a budget balancer, and finallythe late Neville Chamberlain said " It isfantastic to suggest that the Road Fundshould be used for the making of roads,"and took the lot. Motorists are now beingprosecuted . for the so-called offence ofcausing obstruction.

3.-As the law is at present there is nodefence against such a charge. If a motoristproves, for example, that his car has not causedobstruction to any other vehicle or vehicles,the police rely upon the old unreasonablephrase " Causing obstruction to vehicles onthe roads, or which might reasonably havebeen expected to be there."

4.-Yet the police sought and obtainedpowers to remove from the highway anyvehicle causing obstruction and we maintainthat the onus is upon the police to proveobstruction and not merely to give evidenceas to the time the car has been left unattended.We think there shou!d be more warnings andless prose !u:ions.

5.-Dozens of cases are brought in themetropolis alone every year against motoristswho have left their cars in culs-de-sac. Inother cases, such as, for example, in thestreets surrounding Covent Garden, wherethe gravest obstruction is caused by CoventGarden vehicles in those streets (long beyondthe hours when they are entitled to be there),the police do not take action, but as soon asthe street is clear prosecute a few privatemotorists.

Discrimination Necessary6.-We suggest that discrimination should

be made between those who are merely usingtheir cars for pleasure purposes, publicservice vehicles, and those who are compelledto use their cars (and are granted petrol unitsfor that purpose) in the execution of their duty.We think that payment of overtime pay tothe police whilst they are in court is wrongin principle.

Street Parking Should be Permitted7.-Motorists have contributed many

millions of pounds to the State to haveadequate parking places constructed, anduntil that is done we fail to see how theproblem can be solved by prosecution, whichat present is regarded by motorists as merelyanother form of taxation. They are finedfor offences which they cannot helpcommitting. We suggest then that until thevarious plans for reconstruction of the roadsof London and/or cities are brought intobeing motorists should not be fined orprosecuted for obstruction except in caseswhere obstruction is proved. We also suggestthat parking in certain streets should bepermitted until such time as parking placesare provided by the State, and we urge thatthe State must recognise that certain peoplehave to use a car in connection with theirwork. The London Squares and Parks lendthemselves to the parking of vehicles on thenose -in principle.

Lack of Garage Space8.-Even though adequate garage space

were available it is entirely unreasonable toexpect motorists to be putting their cars intoa garage and taking it out several times inthe course of a day. It should be an adequatedefence that the motorist concerned uses acar in connection with his business. It iswell known that the garage accommodationof central London, largely owing to theattitude of the London County Council, istotally inadequate, and it is also well knownthat the authorities have signally failed toappreciate the rapid growth of the motoringindustry and its use in connection withbusiness. The motor car seems still to beregarded by the police and the Ministry ofTransport as a pleasure vehicle. It is, in fact,no longer the privilege of the rich.

No Solution Offered by the Police9.-Sir Alker Tripp has stated that

motorists must understand that the parkingfreedom of the war years is at an end. Buthe does not offer any constructive solutionexcept to threaten motorists with furtherprosecutions.

Causes of Obstructionto.-It is interesting to trace some of the

causes of obstruction, and if suitable remedieswere applied it is our view that congestion inthe streets of busy places would be con-siderably reduced even if it did not vanishaltogether. In the first place there are far

By F.J.C.

too many traffic lights which, being insensitiveto the needs of the moment, needlessly holdup traffic at crossings when other traffic doesnot wish to proceed at right -angles to it.Many of these could usefully be abolishedwithout introducing the need for policecontrol. Some of these lights are so badlytimed that they render ineffectual traffic lightshundreds of yards to the rear. Secondly,where the police do control traffic they willquite often hold up a file of fifty or sixtyvehicles in order to allow one vehicle to cross.

It is also our view that horse-drawn trafficin the streets of London should be forbiddenduring certain hours. It is beyond allargument that one horse-drawn vehicle willcause terrific congestion in places like theStrand and Oxford Street, and build upqueues of traffic which extend far beyond thelimits of four or five traffic lights, thusrendering the latter useless in any case.

Unilateral ParkingII.-The unilateral parking of vehicles has

been successfully adopted in the provinces,and we see no reason why it should not beadopted in certain streets in London. If amotorist cannot park his car and there is notconvenient garage accommodation and he iscompelled to use his car in connection withhis work, how is he causing obstruction ?The recent attitude of the authorities seemsto suggest that he should give up his job.It is our earnest view that it is the duty ofthe authorities to provide adequate parkingfacilities.

Moreover, we maintain that when cases ofobstruction are brought the police should giveevidence that they have had the car undercontinuous observation for .the whole of thetime of the alleged offence.

We do not accept the views of Sir AlkerTripp on this matter, for it is imposingunfair burdens on motorists merely to sendout hordes of police to prosecute motoristsinstead of finding a solution.

Abolish Road Islands12.-The abolition of all road islands,

which merely bottle -neck the road and buildup traffic into a series of clots instead ofkeeping it fluid and apart, would help torelieve the congestion which causes obstruc-tion. It is noted that most of the measuresfor road safety have failed in their object,and as they are merely now obstructivedevices which have reduced traffic in Londonto a farce they should be removed. Theaverage speed through London is about7 m.p.h.

Bus Stopping Places13.-The fixing of the stopping -places of

public service vehicles at traffic lights or atpoints where opposing lines of public servicevehicles stop and completely obstruct theroad is another cause of congestion whichis in need of close investigation. It is not somuch a maximum speed limit which isrequired in London and other cities, but aminimum.

26 THE CYCLIST

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Hush MoneyAFTER receiving a summons for riding without" a rear light, a Leverton (Lines) cyclist wrote toNorth Holland magistrates, saying : " As this is myfirst offence, I am willing to pay an extra amount tokeep my case free from the papers." His fine was thesame as that imposed on other lightless cyclists and hisoffer of hush money was not accepted.

Protecting Child CyclistsIN his report to the Isle of Ely County Road Safety

Committee, the Chief Constable explained thatspecial attention was being paid to the condition ofthe cycles ridden by local schoolchildren, but he wasstruck by the fact that between 8o and goo per cent. ofthem were defective. Even when the poor conditionof the cycles was brought to the attention of parentsit was only in a very few cases that anything was doneto remedy the defects. The Deputy Chief Constablesuggested that a police officer in uniform calling uponparents might make them pay more attention.

Cycle TaxisTHE people of Milan are turning more and more

to the cycle to replace the motor transport whichis almost non-existent. Cycles are being adapted totake two small wheels in front, over which is built anenclosed cabin to carry one passenger in a fair amountof comfort. Another type has an open box containerin front over two wheels in which goods can be carried,and also a passenger if it is a fine day. Also popularare various types of trailers which are used for goodsdeliveries, and for carrying every kind of article, fromfurniture to firewood.

Asking for TroubleA CYCLIST riding along the North Road near

Stamford, Lines, was surprised to see two birdswhizz past him, as if jet-propelled, and crash into thebonnet of an approaching car. The motorist stoppedand picked up one badly injured bird and wrung itsneck. Then lie started to pick up the second bird andfound himself viciously attacked by a hawk, which wasnot at all pleased at having been robbed of the partridgeit was chasing.

Rising Cost of LivingTHE cost of everything else has gone up, so

Huntingdon magistrates have decided that allcyclists charged with riding without lights in futurewill be fined La at least. The magistrates have beenimposing los. fines for some considerable time, but theyfeel that if the fines are larger there will be feweroffenders.

Excessive Fuel ConsumptionTT was reported by the treasurer of the Fenland RoadI

Racing Association, at the Association's meetingat Wisbech, Cambs, that the accounts showed a loss of£20, owing to heavy expenses incurred in the feedingof riders taking part in the open time trial. Apart fromthis, everything was satisfactory. Arrangements weremade for the 1947 events, with the exception of the" Open fa."

Beware of BargainsDURI N G the hearing of four charges of cycle

stealing and four of receiving at Market Rasen,Lines, the chairman of the Bench remarked that thecases ought to warn people not to buy a cycle oranything else from someone they did not know. " Ifan unknown person wants to sell you anything," hesaid, " make sure of his bona -fides. Make sure youknow whom you are dealing with, so that you can producehim if the need arises."

Behind the TimesAN M.P. has suggested to the

Ministry of Transport that" cats -eye " reflectors should befitted to bicycle pedals. Reflectorsof this type were available in theshops before the war, but even ifevery cyclist used them themotorist, sitting behind -his twinsearchlights, would plaintivelymoan: "I didn't see the cyclist."

Still WaitingTIT spent zo years of my

life waiting at this crossing,"said a county councillor at themeeting of the Isle of Ely HighwaysCommittee, when considerationwas once again given to thebridging of the level crossing atMarch, at a cost of some £92,000.He added : " Here is a main roadcarrying heavy traffic and we havenever done anything to it toimprove facilities for erasing therailway." No definite decision hasyet been arrived at, although itwas stated that the road has neverbeen altered for 5o years.

Willing to HelpQENTENCED to three months'" imprisonment at Nottinghamfor the theft of a bicycle andother articles from his stepmother,a man asked the Bench: " Excuseme, but can't you make it six

months ? " The chairman politely agreed to theman's request.

Roller -skater v. CyclistMR. EDWARD FIRTH, former licensee of the

Tudor Hotel, Tudor Road, Leicester, who hasjust died at the age of 6o, was at one time a professionalroller -skater, and in Pato at Sheffield he was the firstman on roller-skates to beat a cyclist in a race.

Sportsman's DeathMR. WILLIAM H. URTON,

managing director of the Chester-field firm of ironmongers, Messrs.William Urton, Ltd., who has diedat the age of 75, was in his youngerdays a keen cyclist and a one-timepresident of the Chesterfield CyclingClub. For some time he served witha cyclists' company of the localSecond Volunteer Battalion, whichhe, joined in 1894. Mr. Urton wasan all-round sportsman, being a fineshot and swimmer and a skilfulangler.

A Good FightFOR many years the Marquess of

Bristol regularly cycled from hisWest Suffolk seat at Ickworth toattend the County Council meetingsat Bury St. Edmunds, refusing to usea car, but now, at 83, he has decidedthat his future trips will have to liemade by car. He feels that cyclinghas become a little too strenuous.

Not so BlindAMAN who appeared at Widnes

(Lanes) Police Court was statedto be nearly blind, but his blindnesshad apparently not prevented him

.from stealing bicycles. He pleadedguilty to nine charges and wasfined £s.

Up to the ParentsPARENTS in the Isle of Ely whose

children are found by the policeto be riding cycles that are defectivein any way will receive a reportsetting out the defects and suggestingthat they should be put right.There is no compulsion upon anyparent, but if a child has an accidentthrough a faulty cycle and the parenthas previously been warned there islittle doubt as to who is responsible.

Cyclists Won't PlayMEMBERS of Loughborough

(Leics) Town Council havebeen complaining that local cyclistsseem to be under the impression thatthe town's one-way streets are two-way streets where a cyclist isconcerned. The police have beeninstructed to keep an eye open for anyfuture offenders.

New Type CycleAN American manufacturer has

produced a new pattern light-weight cycle weighing about 1 9pounds, made from an aluminium

January, 1947

alloy. The frame is of unconventional design and thereare ball -bearing disc wheels measuring only 12 inchesby 1.75 inches.

Reluctant AdmirationAT the inquest at Norwich on an 85 -year -old cyclist,

who was described as " rather headstrong aboutcycling " and was killed when he fell from his machinein front of a car, the coroner commented : " We can'thelp admiring these old men, but they ought not to doit." A son told the coroner that his father had been akeen cyclist all his life, having ridden ever since thedays of the old " penny-farthings."

Cyclists and Pedestrians OnlyR EDF ORD Town Council have decided to build a" permanent bridge between Queen's Park, Bedford,and Kempston, for the use of cyclists and pedestriansonly, instead of a Bailey bridge as previously suggestedas an alternative scheme. The proposed new bridgewill cost £4,800.

No Half MeasuresDAVE,NTRY AND DISTRICT ROAD SAFETY

COMMITTEE is planning an all-out effort toimprove safety on the roads in its area. Some £1,300a year may be spent on accident prevention and theeducation of children in road safety, and the chairmanaims to have a road -safety programme with a set aimfor each month of the year. He told the committeethat too many local authorities have been satisfied withholding a road safety week once a year and thenforgetting about the whole thing for the rest of theyear. Practical demonstrations in road safety techniquefor child cyclists and pedestrians, rather than postersand talks, arc also planned.

Courtesy Club for GrimsbyRIMSBY ROAD SAFETY COMMITTEE have

decided upon the formation of a branch of theMotorists' Courtesy Club in an endeavour to bringback to the town that road courtesy which seems tohave disappeared altogether. They feel it is mostessential that traffic conditions in the town should beimproved without delay and that this improvementwill depend upon the efforts of all road -users and notonly motorists.

GodalmincsSurrai.

Alwari or narrow streets 404ancient koaser. 4 skcki. t,Ike.well Market *easealike H..gth Sheet -

S6Z115,,t412P.NOtIt4


Around the Wheelworld

The Champions' ConcertTHE Champions' Concert at the Albert

Hall on November 30th was, from anorganisation point of view, a great success,in that the hall was packed with 7,000 cyclistsand that io,000 people were disappointed.

The chairman was A. E. Armstrong,chairman of the R.T.T.C., and the mainevent, of course, was the presentation oftrophies and medallions to the winners ofR.T.T.C. championships and the Britishbest all-rounder competition of 1946.

Interspersed in the programme were anumber of variety turns, including PercivalMackey and his Orchestra, the Gordon RayGirls, Mackenzie Reid .and Dorothy, SandyLane, Jass and Jessie, Arnold Greir at theOrgan, the Ben Abderrahman Wassan Troupe,Tommy Fields, Tommy Jover, Raff and Fe,and the Melomaniacs. There was, of course,the usual roller racing contest. 'The prizeswere presented by Miss Doris Miller, V.A.D.

The audience was an enthusiastic one,but the evening was marred by acts of hooli-ganism which we hope the promoters willtake steps to avoid next year.

During one of the turns, a brilliantlyperformed one, coins were thrown on to thestage, and even the commentator was notgiven a fair hearing. There were cat -callsand rattles, whilst pieces of paper and impro-vised paper gliders were freely flitted aboutthe audience and drifted on to the stage.

This is a very bad advertisement indeedfor cycling, especially when it is the biggestevent in the cycling calendar, and there arepresent representatives not only of thenational Press but of every branch of theindustry, the sport and the pastime.

It should have been possible out of a poolof 22,000 applicants to have exercised someselective discretion in the allocation of tickets,and for the promoters to have seen thatthere were an adequate number of stewardsto eject those who were making a nuisanceof themselves. We do not want kerbstonewheelers and guttersnipes to damage ourmovement.

The barracking and interruptions were aninsult to all those who had worked so hardto provide a most pleasant evening for7,000 cyclists.

B.L.R.C. London Section Annual DinnerTHE Annual Dinner of the London

Section of the B.L.R.C. was held atChez Auguste on November 22nd, and ittook the form of a dinner, dance and cabaret.Over zoo members and guests sat down toan excellent meal, and my one criticism wasthat there were far too many speeches, andthat each of them was too long.

Most of the speakers drifted from thetheme of their toasts so that we found thetoast of the visitors being used for propagandafor massed -start racing when it should havebeen apparent that everyone was awareof the facts. However, it was very evidentfrom the enthusiastic audience that therewas no possibility, as was fondly hoped byrival bodies, of the movement dying.

Mr. F. J. Camm, in proposing the toastof the section, paid tribute to all of theofficials, particularly E. Lawton, theGeneral Secretary. Previous speakers hadcriticised the N.C.U., and he said, " Demortuis nil nisi bonum"-speak no ill of thedud ! He advised the N.C.U. to go intovoluntary liquidation to reconstruct. Themembership of the section had grown in the

By ICARUS

short space of four years from 70 to 300,and this was typical of the growth of themovement throughout the country.

League events had brought more beneficialpublicity to cycling in the national Pressthan it had had in its whole history.

Guests included Mr. H. H. England, RexColey, E. Coles -Webb, whilst Jimmy Kainearned a just tribute for his zeal and energy.Many others prominently associated withthe cycling movement, must have gone awayimpressed with the strength of the League.

The work of the section has been greatlyextended during 1946. The Irish meetingwas especially successful. A. H. Clark hasdone a vast amount of work as Hon. EventsOrganiser.

The chairman, D. Carey, presided.

The Charlotteville Annual DinnerTHE president of the Charlotteville Cycling

Club, A. V. Jenner, presided at theannual dinner of the Club at the Lion Hotel,Guildford. The chief guest was the Mayorof Guildford. As usual the evening was agreat success, with inter -entertainment pro-vided by Lisle Hambourger, Tom Morganand Dorothy Southon.

The Mayor of Guildford, in respondingto the toast of the guests, dealt with theorigin of Charlotteville. He had traced itback to Charlotte, wife of Dr. Fell, who atone time resided in Guildford during theperiod when streets were named after persons.

The history of the Charlotteville is toowell known to need repetition here. It wasfounded 5o years ago and was responsiblefor the organisation of the first massed -startrace.

During the past year no less than 40new members had joined the club, whichnow ranks among the leading and mostprogressive clubs of the country.

The toast of the club was proposed byW. H. Townsend, with responses by H. K.Evans, C. V. Pilbeam, and A. Gettings.The Service and ex -Servicemen were toastedby the chairman, with responses by R. G.Best and R. Puttock, whilst the club presidentwas proposed by H. H. England. Over 12omembers and guests sat down to an excellentmeal.

Tributes were paid by all to Vic Jenner.

Is the N.C.U. Redundant ?T HAVE received the following letterI from D. V. Singleton, of Northolt :" Having just read your article in the

December issue of THE CYCLIST, by R. L.Jefferson, Is the N.C.U. Redundant ? ' Ishould like to compliment the writer on hisoutspoken criticism of the N.C.U.

" I am a member of the N.C.U. myself,rejoining through a local club, without dueconsideration of the pros and cons, after myreturn from the Forces. Since then I haveread criticisms of all kinds through themedium of the cycling press.

" The club I belong to is definitely N.C.U.in its policy, and when once or twice I havebroached the subject of the B.L.R.C. Iwas immediately howled down. I havethought several times of resigning and joininga club affiliated to the B.L.R.C., but, ofcourse, I have made a good many friends inthe club, and am very interested in itsactivities, which makes me loath to leave it.I consider that I'm not the only one who isin the same boat, and consequently hangon to the N.C.U. and its antiquated policies."

Three Boys Cycle Through a Film

AFULL length film, dealing with theadventures of three boy cyclists in the

English countryside, has just been completed,and is shortly to be released throughoutBritain.

The film is entitled Nothing Venture,and tells the story of three i6 -year -oldtown boys from Hull, Newcastle and Bradford,who cycle through Surrey and Sussex intoHampshire to meet the Queen Mary atSouthampton docks.

The film has been produced by JohnBaxter, who made Love on the Dole and TheCommon Touch, and has now started workon a new comedy film starring Frank Randle.

During the summer Mr. Baxter filmedsequences in Sussex and Surrey, showingthe three boys cycling down to the coast.Nearly all of the film is out-of-doors, andbesides providing grand entertainment, thepicture brings a healthy, open-air feelingto the town audiences, especially to youth.

Motorists and Blind Pedestrians

ALARGE number of motorists and cyclistsappear to be unaware of the fact that,

with few exceptions, the carrying of a whitestick by a pedestrian denotes that the user isblind.

Although these sticks are easily recognisable,they obviously cannot be of any real valueunless all are aware of their significance, andthe R.A.C. appeals to motorists, cyclists and,indeed, all classes of road users, to lookout for the white sticks, particularly in theurban areas, and to extend every possiblecourtesy and consideration to those who carrythem, particularly at pedestrian crossings.

Manifesto

THE following manifesto is issued to Britishroad men by the B.L.R.C. :

(i) Arrange a meeting between the twoEnglish Road Racing bodies, having mutualinternational interests :

(A) Road Time Trials Association.(B) British League of Racing Cyclists.

(2) Such meeting to explore every possiblemethod whereby the Road Sport of Englandcould be controlled by a joint organisationformed of R.T.T.C. and B.L.R.C. members.

(3) This joint organisation shall apply tothe U.C.I. for separate recognition as theruling organisation for Road Sport in England.

(4) That the R.T.T.C. and B.L.R.C. shareU.C.I. representation equally on behalf ofEnglish Road Sport.

(5) That the N.C.U. be recognised as thecontrolling body for Path Racing according toits own constitution, and have U.C.I.representation as such.

(6) That England concentrate on its ownproblems, and that the formation of separateNational Organisations in Scotland, Ireland,and Wales, be encouraged.

(7) That the meeting proposed in (t)be held at the earliest possible opportunityin order that application for InternationalStatus and Representation, on behalf ofBritish Road Men be lodged with the U.C.I.in time to be dealt with at the next U.C.I.Congress, to be held in Luxemburg nextFebruary.

- 28 THE CYCLIST January, 1947

if

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..

WaysideThoughts

By

F J. URRY

Falkland alace ,

Fifeslar-e

'The home of Same& N.11,and united many +tines byMary , Queen et Scots

Old Ideas Crop UpA SHORT time ago the daily Press published an

illustration of a bicycle giving front wheel tractionprovided by a rocking handlebar working a dual chainto the front wheel hub. It is said to be the inventionof a Signor Colletti, of Milan, but the gentleman is along way behind the times, for the Bricknell Hand Gearwas in being in this country nearly half a century ago,had itsfittle day of novelty, and died because it neverwas, afid never can be, a useful aid to cycling. HarryGreen (probably the greatest road rider of all time)created at least one record with the aid-or perhaps itwould be more true to say with the handicap-of theBricknell Gear ; but the device never became evenmildly popular for the simple and sufficient reason itwas not helpful to progress on a bicycle. Nor can sucha device ever be to the average individual. Hand gearsserve an excellent purpose for use on invalid tricycles,but they will never be the slightest value as an accessoryto speed or ease of cycling as we know it. It is rathercurious to observe how frequently exploded ideas ofan earlier time recur in the minds of the new generation,and I am told by our manufacturers that literally hun-dreds of notions are submitted to them embodyingmechanical principles that have been tried and discardedyears ago. It is, indeed, rather astonishing that theearly designers of the bicycle came so very near toperfection in general principles so soon, for the outlineof the modem product has scarcely altered during thelast half century, and improvements have been onlyeffected in details, the major among them being themany varieties of change speed gears. That does notmean to suggest the bicycle has been neglected ; farfrom it, for bearings and tyres, saddles and brakes, thecomfort of sponge rubber grips and resilient front forks,have made their marks on the yard stick towards perfec-tion, while equipment in lamps and luggage receptacles,in camping outfits, tools and the small but necessaryincidentals have created a minor revolution. But thegeneral outline of the bicycle has remained and, in myopinion, will remain; will, indeed, return to the morecomfortable frame angles 68 degs. to 7i degs. ratherthan the steep steering 74 degs. to 75 degs. now favouredby the racing lads. It is to the small things we mustlook for improvements, and to the big developmentin the use of stainless steel, which, in my opinion, isbound to mark the advance of the high-class bicycle.But to expect traction help from the arms, except as afulcrum aid to the legs, is as much nonsense as it isunnatural. Some years before the war the recliningbicycle was in the news. It was going to revolutionisecycling because some expert had ridden a kilometreat fantastic speed ; but as it placed the rider in anunnatural position it never had a chance to develop,not even as a racing machine.

Sound SenseWRITING to the technical Press, I see a touring

cyclist has recently suggested we should planour journeys and then deliberately halve our dailymileage. He argues that we are in too much of a hurry,

and that if the idea of cycletouring is to improveacquaintance with thecountryside and the countrypeople, to see and cherishloveliness and obtain thehuman atmosphere of theland you are roaming, thenI think he is right. Fora long while the emphasishas been on " how manymiles a day you can ride incomfort," rather than howmuch can you see and enjoyby leaving the furlongs totake care of themselves.Most of us are apt to becritical of the motorist whoeats up the miles andimagines he 'knows acountryside because he haspassed through it, but I'mafraid, in our lesser degreeof speed, we are very proneto slip into the same error.I know from my ownyouthful experienct howdifficult it is to travel on abearing rein, as it were,when young activity isloosed on a holiday. Theidea is to get in all wecan during our limitedleisure, and if we misssome of the beauty, historyand romance of journeying-well, we can repair theomissions another time. Ihave fallen for that methodon many occasions, and onsome have made my pilgrim-ages a hurried and palpitat-ing journey, achieving littlebeyond the leagues, andsome of them not quite sohappily attained as t h eservice of a little more timemay have given. After all,cycling. for the majorityof us is just a means to anend, to see our belovedcountry and take a properpride in its history andloveliness. The journeyingitself partly fulfils thesedesires if you go comfortablyenough to see and observe,

and are ever ready to drop a foot, or take a short detourto investigate. That, I take it, is what my mentor meanswhen he says, " plan your daily journey and then halvethe mileage or double the time." It is sound sensefor a tourist to accept : indeed, it is more than that,for it implies the real touring spirit that " to travel isbetter than to arrive." For myself it leaves a feelingthat right now I should love to put it into practice,and with one good friend go investigating nooks andcorners during a season of the year when few otherpeople are out and about. I have always wanted tosee many of the places I know in the spring and summerglory under the impact of winter, but never yet have Ihad the pluck or temerity or speculative spirit to riskpledging a summer holiday for a winter one. There is,of course, the long nights to consider, but eight hoursof daylight are enough to make many excursions, andthere are always books to read and on moonlit nightsthe lonely loveliness of a thousand places I knowwithin a few miles of the warm comfort of the inn.Some day I will cling close to the Gulf Stream andsee the western coast of Scotland in its winter setting,and then the day's mileage will beshort indeed but full of joy and interest,and perhaps the rumbling of storm.

H

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11511115.111U

Stratford -or\.-Avom. ,Wurar......

Harvard 'Howse WI* to IS% (fight)and the old Carrick fanMite oatTles a{ half +mho- work..

Joy in UtilityIT is a very pleasant thing to ride to work in the

moming---even if the day be a poor sample ofwinter-with the feeling that you can keep on doingthis for ever, for it goes to show how excellent regularcycling is for an elderly man. Of course, I know wellenough that can't occur, and a time will probably comewhen weight of years will put me on the shelf, unlesssomeone bumps me off in the -fullness of my activity.Yet after 57 winters of fairly constant riding I find theprocess as fresh and gay as ever, and would not changemy method of locomotion for anything or any otherform of transport, for I believe, rightly or wrongly,that I owe my health and happiness more to cyclingthan any other action of life. I've said that before onnumerous occasions, and in repeating it now I want toemphasise the fact that neither traffic nor poorly -surfaced roads, nor the knowledge that my averagetravel speed is slowly dropping, makes my daily journeysless interesting, and certainly not more dangerous.That latter is the point so often made by the uninitiated,the sense of danger. Well, I just haven't got it,mainly for the reason, I expect, that I've grown up withthe conditions and slipped, into the stream of themsubconsciously. The immunity I enjoy from accidentsand the fear of accidents is due, I think, to circumspecttravel. I'm seldom in a rush to get there, for at bestthe saving can only be a few minutes on a seven milesjourney, and it is far better to take those minutesfrom the leisure times of morning and evening thanendeavour to conserve them on the road. And anyonewith a reasonable sense of road conduct and a knowledgeof cycling limitations is a pretty safe unit in the trafficstream, not only from the point of mobility, but becauseof the gathered experience of what the other fellow islikely to do in a given set of circumstances. In practiceit is remarkable how frequently this " traffic instinct "turns out right and avoids the perilous position. AM.O.T. official recently said that carelessness is theoverriding fault of the average road user, no matterwhat his vehicle, from shoes to a Rolls, andi I'm quitecertain he is right. Years, of course, make a difference,for they impose circumspection on the performer, andperhaps a much more charitable outlook ; and thosefacts in themselves are jolly good reasons why theregular daily cyclist should think twice before he givesup his utility journeys.

We're Getting OnWE are going to get good tyres again in the near

future. No more synthetic rubber, which, forall the good service it rendered to us during the waryears, never failed to remind me of linoleum wheneverI handled a " war grade." It is high time, too, as faras I am concerned, for I'm down to my last " Sprite "spare, and on two of my machines tandems of that tyreilk are servicing the rear wheels. So my little stockof " Sprites " bought in the summer of 1940 are justseeing me through. The last of them are wearing outrather quickly, developing little faults in the alliedcotton and rubber; not surprising when it is remem-bered they have been in stock for six yearl Tyresdo not improve with keeping once they have matured,and I have been agreeably satisfied that these daintycovers have given me such excellent service through thetroubled times since 1940. Soon we shall have " Sprites"again, that excellently named product of Dunlopwhich certainly gives a good bicycle an elf -like loveli-ness ; and when they are purchasable I shall be com-pelled to have a wholesale re -tyre, even if I have to drawon my " post-war credit."

7Y0

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30 THE CYCLIST January, 1947_ -

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The Cycle and the RailwaysACCORDING to the National Committee

on Cycling (a body which does a dealof most useful work in the interests of thecycling movement) there is only one of thebig London railway termini (Charing Cross)which has adequate storage room forbicycles ! But following discussions betweenrepresentatives of the railway companies andthe committee, better things are promisedin the future, and it is good news that theGreat Western company has already under-taken to provide 793 more cycle stands atits stations. In view of the fact thatall connected with the cycling movementexpect that 1947 will see a very big growthin touring, which will, of course, mean thatlarger numbers of cycles will be carried to" vantage points " by train, this attentionto the storage problem is acceptable . . .

and it is of real importance, of course, tothe men and women who cycle to stationsand wish to leave their bikes there untilthe return journey home in the evening.

The Export Target for Bicycles

AS is well known, many industries, par-ticularly in the engineering and allied

trades, were set an " export target "-manyof the industries concerned being asked tomake an effort to improve exports by atleast 75 per cent. over pre-war. The cycleindustry has passed the target, and is nowplaying a vital part in the country's exporttrade. Of course, as in other industries, thehome market must suffer to an extent, butI think that by now everyone realises thatexport trade is vital to our national recovery. . . and in any case the cycle industry hasnot neglected the home market, as a glancein the average cycle dealer's shop will prove ;and, what is really important, the industryhas seen to it that quality has not been

lowered . . . the Britishbike is still the world'sbest!

Seed -time and Harvest"REMEMBER the dire

prophecies aboutfamine and starvation atthe time of the harvest ?Violent storms had flat-tened the corn in EastAnglian fields ; farmerseverywhere were facedwith certain ruin ; and therelentless rain fell on everyfield of wheat and oats andbarley. Well, I was everan optimist so far as har-vests are concerned, and Isomehow felt, even whenthe newspaper headlineswere at their gloomiest,that it couldn't be as badas all that! And recentlyI have cycled in that veryEast Anglia which was sohard hit by the weather. . . and Suffolk farmershave smiled at me overtankards of ale in villageinns, and admitted thatthey " got through," andthat in some districts theharvest was remarkablygood.

Festive WindowsALL through the war

years I used to sighfor the " Christmassy "

spirit in our streets and towns and shopwindows. I think that everyone missed it.Now, as December arrives, many shops havemanaged to deck their windows and introducea little of the Yuletide atmosphere. Thisweek I noticed two cycle shops which had" gone gay "-imitation holly, colourfulstreamers, and a Christmas message. It isall to the good . . . and from a retail tradingpoint of view we should never forget thatChristinas has great significance. In normaltimes, when goods were in free supply, itwas the spending season par excellence!

Back at " The Towers "THE Cycle Union, over which Major H. R.

Watling presides with dignity andefficiency, is back in its old quarters at"The Towers," in Coventry. The premiseswere damaged during the Coventry blitz,and the union removed to temporarypremises in Kenilworth. I feel sure that" the Major " is glad to be back in his oldhome . . . where such admirable work hasbeen done in the interests of the cycleindustry, and, one may be sure, that goodwork will continue!

Essence of EssexTOT many tourists would regard Essex,

I fancy, as a " star " county from thescenic point of view. Indeed, I have heardit derided as a touring ground . .. but I havegenerally found that its detractors have beenquite ignorant of its many fine features andthe beauty of its interior. It is too oftenjudged by its " London fringe " ; but Ilfordand the suburbs are not Essex! Ride, asI have done, into the interior and saunteraround villages like Tolleshunt D'Arcy, andlinger in the " Rodings," and you will findthat Essex has great charm. It possesses

some of the best agricultural land in allEngland, and some of its villages are asunspoiled and old-fashioned as any you willfind anywhere ; oil -lamps are the onlyillumination in some of its cottages, andthe ways of the people are the ways ofyesteryear. One day when the winter sunshines (and it does quite often!) put yourbike on the train at Liverpool Street andjourney, say, to Chelmsford-and from therecycle around unknown Essex ; talk with menfrom farm and field ; sip ale in villagetaverns ; look at some of the old churchesof the county-and you will come back totown feeling that you have made some gooddiscoveries and found a new and delightfultouring area.

Breaking Down the BarriersTHAT, I think, might well be regarded

as one of the jobs of that active anduseful organisation, the " Roadfarers' Club,"of which Lord Brabazon is the energeticpresident. I am proud to be a councilmember of the club, and I always feel,when at its meetings, that it is performinga vital function in breaking down the barrierswhich exist between the various classes ofread users. It is so silly to imagine thatthe community can be split up into" cyclists " and " motorists " and " pedes-trians." At different times a man is allthree! What is wanted, if the HighwayCode is to be observed more thoroughly,is a new spirit among road users ; friendli-ness, and the courtesy of the road, insteadof enmity and mistrust. And the " Road-farers " are doing what they can to promotethat " fellowship of the road " which is sovital if accidents arc to be reduced andthe road made safe for all.

India and the BicycleEVERYONE knows that India is being

industrialised . . . quite rapidly. Thischanging of a great territory was bound tocome, and, in the process, " teethingtroubles " are inevitable. I understand thatthe Indian cycle manufacturers are havingthem ; the quality of the Indian -made bikeis criticised by the Bombay Cycle Merchants'Association, who oppose the imposition ofa tariff against the import of British bicycles.Of course, the Merchants' Association is inagreement with the fostering of Indianindigenous industries, but naturally isvitally concerned with quality, and thereforelikes the imported British machine .. . whichin India, as everywhere, gives completesatisfaction. It is an interesting angle, andI recall that I was informed recently thatin pre-war days India bought from Britainbetween 15o,000 and zoo,000 cycles a year.

Nocturne in JanuaryEVERY month is a good cycling month

. . . to the lover of the countryside!And I like a night ride in January, whenthere is a trace of frost and the road ishard and the moon is up. Good, on sucha night, to ride out into the quiet world andfeel the nip of the night air on one's cheekand see the stern beauty of the bare treesand the twinkle of lights in cottage windows. . . and the red blinds of the inn window,welcoming cne to warmth and comfortinside. Maybe the pool by Bracken Farmis freezing over . . . and one may lookjoyously forward to skating. A stray rabbitdarts across the road by Coppice End, andfrom a ruined barn comes the hoot of awakeful owl. Salute to January!

A

32 THE CYCLIST January, 1947

M.

...

My Pointof View

a

LulliNgtoNcharch.Susses..

One at Inglandrsmallesickurches. Alately littlebuilding surrounded by beesOA the main mad from Vied.Dorn to AtfristOn...Only the chancel nunamt ofl'Ae enamel txuldtttyah,dtwasdestnyied white% ago. l

By " WAYFARER"

Compote of Conversation

IT is rather interesting to one who for the past fewyears has been submerged in a suburban job,

hardly ever finding it necessary to adventure into thecity centre, to come across so many familiar faces nowthat the position of affairs is reversed, and every dayfinds him pacing (on business intent) thronged streets.A light cornea into the seyes of a passer-by and his paceslackens. I, too, slow down. We stop and shakehands. " ' Wayfarer,' isn't it ? " says the semi -stranger, and a guilty plea is entered. " I met you lastat Dolgelley, x9 or 20 years ago. . . . Are you still onthe road . . . ? I met you one Sunday between Wiganand Warrington.... I don't suppose you'll remember,but you provided me with a very fine Irish tour someyears back. . . . I've still got that bike for which youdrew up the specification in 193o. .. I'm a motorist,now-wife and family, y'know-but I think' with greatpleasure of my cycling days.... I haven't done muchin recent years, but the kids are growing up and thewife and I are coming back to cycling. . . . I- indulgein mountaineering, but the old bike's still in use.. .Yes, I'm still getting them round. . . . It's a grandgame, isn't it ? And what a time we had ,during thewar, with no motors about . . . ! Still lecturing . . . ?Been to the Cotswolds lately. . . . ? Still ridingfixed ? " We shake hands again, the writer feelingrefreshed by a momentary glimpse into the past, andglad to have been able to help, or inspire, this man andthat, in one way or another.

Persisting JoyALWAYS, at this time of the year, I am conscious

of an urge to say my little piece with regard to aphase of cycling which has held me in its grip for manya long day. When the autumn arrives and, thanks toour " interference with the clock," the hour for lighting-up makes its leap forward, necessitating the illuminationof bicycles immediately after tea, then I am ready withmy gas lamp, and I experience anew the persisting joyof riding in the dark.. Up to the first Sunday in OctoberI had " made do " with an electric battery lamp, butthis type of light in inadequate- for my night -ridingprogramme, and one of my gas -lamps was then broughtback into use after a summer's idleness. This lamp,which is a small one and cost 5s. before the war (perhapsit was before the other war !)-what the price would benow, if the article were obtainable, I do not know-ispart of my " fleet " of gas -lamps and is good enoughfor most occasions, though on really black nights andfor my longer journeys I resort to a much bigger lamp,the light from which enables one (in the words of awitty friend) " to see people's underclothing! " But,big or little, I like to sit behind a goodly measure ofillumination, which allows me clearly to see where I amgoing and lets other people know I am coming. Frommy point of view, any element of danger in connectionwith night -riding is very largely minimised by the useof a really effective head -lamp. This apart, however,I find an infinite joy about cycling in the dark, and thepleasures attendant on this phase of our pastime dosomething to water down my regret at the departureof summer.

Recurring FaultT BELIEVE that I could, with advantage, write aA paragraph every month on the subject of tyreinflation. A tremendous amount of propaganda en the

subject is still needed. Forexample (dozens of whichcould be quoted), the otherevening I overtook a ladywho was walking her bicycle.the front tyre being deadflat. Seeing that she had nopump, I asked whether Icould help. My offer wasaccepted, and I had the tyrehard in no time. On in-quiring as to the state ofhealth of the back tyre, shereplied : " Oh, that's allright "-which is just whatit wasn't. I gave her such alook and put that tyre right,too, with a gentle word ofadvice as to the free use ofthe air which is availablein very large quantities.But, bless ye! I don't mindbetting tuppence that boththose tyres are again beingridden in a flabby condition-to the discomfort of thecyclist and the ultimate gainof the tyre manufacturer.

Fifty Years AgoAA Y daily newspaper con-

tinues to print, fromtime to time, a so -year -oldparagraph relating to roadmatters. For instance, we

74d learn on September 27ththat one perSon was knockeddown and injured in thestreets of Birmingham everyday in the year, whileone person was killed everyten days. (That was inx896. In 1946 one mightwell say : " What are youshouting about ? ") Theancient paragraph continues

in this wise : " Under the pressure of continualcomplaint, something is being done to check the' scorching' cyclist from racing in the public thorough-fares." A day or two later, this paragraph was broughtup at a meeting of the Watch Committee, a membersaying that the matter called for serious attention andmoving that it be referred to the Chief Constable forinquiries. The speaker added that he was of theopinion that rubber-tyred machines (bicycles, of course)

whilst beingridden through the centre of the city. That was onSeptember 3oth, 1896. Would anybody like to revivethe suggestion now ? Sornehow, I don't think so !

A Right MoveIT is good to know that the Minister of Town and

Country Planning' has reiterated his promise tomake " an end of outdoor advertising in the country," amethod of publicity which, in some aspects, is horrifying.Particularly to be deplored is the defacement of naturalfeatures of the countryside-rocks, for example-by means of a multitude of posters or by the use ofstencilled wordings ; while, to my way of thinking, theenamelled signs erected by the owners of a chain ofhotels, headed with the silly injunction : " LookOut ! " are a complete eyesore, causing the traveller-causing me-to look out and beware I It is conceivable,of course, that a small amount of " outdoor advertisingin the country " may have its uses. Regulated, and donewith good manners and good taste, it might be unob-jectionable in the case of cyclists, and other lovers of thecountryside.

Nothing New Under the Sun'THE daily Press recently gave a picture of " new

style cycling " consisting of an Italian inventionfor applying power to the front wheel by means of arocking handle -bar. All that this picture proved wasthat there is nothing new under the sun. A version ofthe idea, in the form of the Bricknell Hand Gear, wastried out long years ago, and was accounted a failure-for, I expect, good and sufficient reasons. I do notsuppose that the passing years have altered expertopinion on the subject, and I have no doubt that this

new style cycling " is already as dead as the proverbialdonkey.

Mr. Know-allRATHER obviously, he was a short-term cyclist-

here to -day and gone to-morrow-and he gaveone the impression that he " knew it all." So, when hecommenced to air his knowledge on the. subject of gaslamps, I offered him a little encouragement by way ofquestions. Gas lamps were troublesome things to run.Were they ? I innocently. asked. You had to clean andre -charge them after every using. Have you ? Iinquired. They were messy things to play with. Arethey ? I queried. This repetition infuriated Mr.Know-all, as it was intended to do, and he cried, withundue heat : "Well,. you ought to know. You use gaslamps, don't you ? Aren't they a bally nuisance, anddirty, and all that ? "

So I told him, gently, that each of his statementswas wrong. Gas lamps were really very little troubleto run. In practice, it might be an advantage to cleanand re -charge after every using, but this was notnecessary in connection with a series of short journeys-say five or six such. The dirt from gas lamps, wasgood, hones,, clean dirt-if a trifle smelly-which

was easily removed from the hands. When I turnedthe tables on him and inquired what experience hehad had with gas lamps, he gave me the answer I quiteexpected " None ! "

We Supply the PowerAFEW days ago a letter appeared in one of the

daily newspapers about the desired revival ofyacht -racing. The writer said that he could hearpeople asking : " What is the use of a sailing yacht,pushed about by the wind at to or x2 miles an hour ? "It might equally well be asked (he added) : " Whatis the use of cricket, football, or rowing ? " the answerbeing " that such sports and pastimes create activityof mind and body-a spirit of competition and team-work which, in the hour of the nation's need, has savedher from disaster." So it is with cycling, which bestowssuch remarkable physical and mental gifts upon itsdevotees. Yet there are funny people who say : " Youought to have a motor -cycle !" By the same token itis presumed that the lads who walked from Londonto Brighton the other day ought to have borne in mindthat there is an excellent train service between the twoplaces. By using it they could have saved a lot of time-and some shoe -leather 1

After a period of reflection, I rather .feel that, whenthe Oxford and Cambridge boat race is carried onwith the aid of outboard motors, the funny peoplewill come into their own, and we shall find it difficultto counter the assertion that " You ought to have amotor -cycle "1 For the time being, however, we shallcontinue to supply our own power.

The Speedy WayACOLLEAGUE with whom I was doing a business

journey by motor -car suddenly turned from ourgeneral conversation to comment on the fact that, attimes, the bicycle is the speediest vehicle on the roads.He was referring, in particular, to his own experienceswhen cycling to and from business and participatingin the daily rush-hour traffic, morning and evening,and he admitted that the bicycle was a great source ofconvenience, because it was so readily possible toweave in and out of the crush and to reach one'sdestination long before .the larger units had brokenaway from their slowly advancing queues. 'Phisexperience accords with my own. The bicycle may haveto take second place where longer journeys and clearroads are concerned, but, when there is congestion,the expert cyclist can readily make good progress and" get there first."

Our Enemies

'THESE are the principal (inanimate) enemies ofcycling, I thought to myself on a recent day,

when making my way homewards : Fog. Probably -the worst of the lot-because it does not make cycling" impossible " I It provides us with serious difficultiesand discomforts, and is most bewildering. Usually wecannot ride fast enough to keep warm, and the thickenedatmosphere tends to hurt the eyes (in my case, it doesits best to induce a headache), and makes breathing 'hard, while a moist fog is as wet as rain-as rain it is,in another forma Fog adds to the dangers of cycling(that never worries me), but consolation is to be derivedfrom the fact that it puts a brake on all forms of traffic,so that the hazards of travel are really relative. Ofcourse, it is disconcerting when you fancy that you arewell on your own side of the road to find yourself'buthping , into the offside gutter ! One - disturbingfeature about fog is that it seems to get into your mind,so that, if you leave your proper track, it is difficult toreconstruct the hidden scene and thus to return tothe - path of rectitude. At least, that has been myexperience.

Snow is No. z enemy. Falling snow is bad enough- 'how painful it is when the pellets hit one's eyes I-but lying snow, according to its depth and its ultimata. churned -up condition, makes cycling very difficult,if not more or less out of the question. Time was whenone revelled in cycling, or in trying to cycle, througha coating of snow, but one was younger then, and fallsdid not matter. Moreover, in those days one had .

almost a monopoly of the roads.While it lasts, a glazed frost, or silver thaw, is No. 3

enemy. It makes cycling extremely difficult, andhere again the presence of other traffic is a factor forconsideration. It is hard to maintain an even keelwhen the roads are like glass-rare occurrence, ofcourse-and I, for my part, am prepared for the timebeing to retire and " give it best." Sometimes, ofcourse, you are caught napping and have- to " facethe music " in order to return home. And sometimesan odd patch or two of slipperiness leads to yotirundoing. The last skid I had-ten to fifteen years ago-was caused by running without the slightest warning,in the. dark, on to a highly treacherous piece of road. ;The tandem I -was steering lay down very rapidly andthe two riders accompanied it " without the option " !

I do not reckon the wind ai being of necessity an '

enemy of cycling. It can be, and a very ruthlessenemy, too. It can also be a jolly good friend tocyclists. Nor do I count hills as coming in the enetMs.-class, especially as they go in both directions-downand up. Certain of our hilly districts can be prettytrying-one thinks of, say. the North Riding ofYorkshire .or .the southern portion of Shropshire-where the succession of banks seems endless. Youtake half -an -hour to pled up a hill and flash down theother side in five minutes. No : hills should not becounted amongst our enemies. On the other hand,there are certain circumstances in which I would beready to view a flat country as definitely a menace tocycling.. In my opinion, rain is not in the enemy class,nor is extreme heat or cold. And certainly notdarkness.

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