Editorial - Slide Rule · NEWSLETTER of the UK SLIDE RULE CIRCLE Editor: Colin Barnes, 189 Mildenhall Road, Fordham, Ely, Cambs. CB7 5NW England Tel: 01638 720317 e-mail: [email protected]

ISSN 1466-3570

February 2006 No. 22

NEWSLETTER of the UK SLIDE RULE CIRCLEEditor: Colin Barnes, 189 Mildenhall Road, Fordham, Ely, Cambs. CB7 5NW England

Tel: 01638 720317 e-mail: [email protected]

Editorial

Each time I start on an issue of ournewsletter I wonder if I will have enoughmaterial for a reasonable edition. So far (touchwood) I haven’t had to worry. This issue, ishowever, a little sparse mainly because of thelate issue of SS 21 which in turn was due to theadditional work involved in organising IM2005 and publication of the Proceedings.

What will 2006 bring? Newmembers, new discoveries and more articles Itrust. Personally I look forward to all these buthopefully not all at once.

Further notes for this editorial areovershadowed by the article that follows. Johnwas a founding member of the UKSRC andcontributed regularly to our newsletter andGazette. He also took an active role in ourInternational Meetings and his knowledge andexpertise will be sorely missed.

John V. Knott. 1919 – 2005

John was the man most of us firstcontacted when we discovered that there wereother slide rule collectors out there, in myparticular case it was via the good offices ofBlundell Harling who were still selling sliderules at that time. We were rewarded byfinding a thoroughly nice and knowledgeablechap, who was obviously not mad (as manyfeared) and who was generous in the extremeswith sharing the information that he had. Hedealt with us new-comers to the world of sliderules, with great patience and good humour,and certainly in my case we became goodfriends and regular and prolific correspondentsmuch to the amusement of both families. Johnhad started collecting slide rules in 1987,sometime after he retired from the GeneralRailway Signalling Co of Rochester USAwhere he had finished up as Manager of theQuality Control Department. He was a typical

engineer of his generation, eminently practical,pragmatic and interested in all sorts of things.

John photographed with a part of his collectionin about 1989

Like many of his age, he had startedas an apprentice, and then joined a largeengineering concern, in his case MetropolitanVickers in Manchester in 1938. Apart frombeing a founder member of the UKSRC (and apossible catalyst for its formation), he was alsoan early member of the Oughtred Society. Heexhibited his slide rules at his home Museumin Bolton in 1988 and 1996/7, in SalfordMuseum in 1989, and in Manchester ScienceMuseum in 1993. These exhibitions were apleasure to visit as I can well remember havingseen his 1996/7 exhibition in Bolton. He alsohad an interest in musical boxes and clocks aswell as slide rules, he maintained and repairedelectro-mechanical devices as a hobby,including a collection of thirty Victorianmusical boxes in Salford Museum and

1©2006 The UK Slide Rule Circle and the contributors

Skid Stick Issue 22February 2006

mechanical machines in Salford and BoltonMuseums.

John collapsed suddenly and died afew days later in a hospital in Manchester onthe 17th December 2005 at the age of 86. Wehave all lost a friend and the slide rulecollecting fraternity will be smaller and poorerwithout John. Within the UKSRC he was aregular and enthusiastic contributor to ourpublications. We will miss his wideknowledge, wise council and wicked sense ofhumour.

The UKSRC sends its condolences tohis wife Barbara, two sons and their families.

[If anyone would care to contribute toJohn’s memory, the family have asked that anydonations should be made to the BoltonCoronary Care Appeal at the Royal BoltonHospital, Minerva Road, Farnsworth, Bolton,Lancs. BL4 0JR in the name of John Knott.The UKSRC has made a modest contribution.]

John “in action” with some of the delegates atthe 2002 International Meeting of Slide Rule

Collectors in Leamington Spa.

Directory Changes

Bruce Williams new address and telephone 7 St. Mary Le Park Court

Albert Bridge RoadLondon SW11 4PJ

U.K.0207 924 1795

Chris Jones change of email [email protected]

T Gordon Roberts change of email [email protected]

Dieter von Jezierski change of email [email protected]

New Member

The UKSRC welcomes our first new memberof 2006. Mike Konschak

1944 Quail CircleLouisville CO 80027

[email protected]

www.sliderulemuseum.com01 303 673 9853

“Playing the Moldovans atTennis”

Colin Barnes

An intriguing name for a book but itgets better (or worse)! What’s the connectionbetween The Beatles and slide rules? Thisbook provides the answer and I quote:

Strawberry Field is more than just a song. Itis, and always has been, a working SalvationArmy children’s home the gates of which havebecome something of a shrine to Beatlesdevotees. They aren’t normally opened forfans, but this year [c. 2000] Cavern City Tourshad landed something of a coup when it hadpersuaded the Christian Soldiers to pack thechildren off for the day so that a huge gardenparty could be thrown, with “Beatles” bandsplaying all afternoon. A rare treat. And like alot of rare treats, a major disappointment. Togo through the gates into Strawberry Field isto shatter any illusion that you may have as tothe magical quality of the place. The originalbuildings, which matched the age of the gates,had long since been demolished and replacedwith new ones which had been designed by aman with a slide rule and access to a job lot ofcheap and ugly windows.

Extract from “Playing the Moldovans atTennis” by Tony Hawks, Random House,ISBN 0 09 187456 4, Price £6.99.

Oughtred Society Subscriptions

The time of year has come when OSsubscriptions are due for renewal. The rate foroverseas members remains at US$40.00 thisyear. For those paying by credit card paymentmay be paid direct to the OS PayPal account [email protected] Anyone with aUS$ account or funds in cash may send theirsubscription by mail to the Secretary, TedHume, P.O. Box 63021, SAN ANGELO, TX76906, USA. Cheques payable to TheOughtred Society please.

www.sliderules.org.uk2

UK members without these faciliriesmay send their subscription in the form of acheque to the value of £25.00 to the Editor andmade payable to Colin Barnes. These chequeswill be consolidated, transferred and forwardedto the OS by PayPal with a record of yourpayment. Please ensure that all payments aremade before the end of March.

Staticinemeter & SkidStickPeter Hopp

I have a friend who, apart from beinga mad keen Morganoid and general three-wheeler fanatic, and amongst other claims tofame, is the editor of “The Bulletin”, themonthly magazine of the Morgan ThreeWheeler Club, with whom I delight inswapping unlikely stories. He normally “wins”and has been quoted as saying; “For me, lifehas been a constant struggle between cripplingmodesty and justifiable smugness.” I cannotargue. To produce a monthly magazine of thequality of “The Bulletin” is no mean feat, andnot one I would wish to emulate! Assisting ourHon. Ed. on SS now and again, and theGazette once a year are more than enough.

We were exchanging views on thenames of our various organs (Skid Stick andthe Gazette, you fool!) which prompted thefollowing reminiscence from him:

“On seeing the word SkidStick I wasreminded that in my time with BP I wasresponsible for publications supporting the saleof, among other things, hydraulic fluids. Onerange of these fluids was so slippery that it wasused in flight simulators and intricate machinetools. The slipperiness, or more precisely thelack of stick-slip, came from sperm oil, whichwas an additive used in surprisingly smallproportions. When the killing of sperm whalesbecame impolite, the researchers had to lookfor an additive that was equally effective, sothey designed a machine called aStaticinemeter which gave all lubricants anumberable property in that respect (the skid-stickiness), and they tested every slipperysubstance under the sun. Eventually they foundan additive that was so much better than spermoil that the makers of flight simulators had tore-program their software because everythingwas hitting the bump stops. If you want to useall this in everyday conversation, feel free.” SoI am!

Subsequently I did a web search onStaticinemeter using Google which came up

with a mere three “hits”; two of which relatedto a cutting oil, Spedol 05W, and the third alengthy list of various oils, one of which wasthe following: NIMASO FRIMOD STICK-SLIPPERFORMANCE MACHINE TOOL OILISO 32, 68, 220 PERFORMANCEPROFILE: NIMASO FRIMOD SSP is apremium quality, friction performance,multipurpose workshop oil, formulated withhighly refined base stocks and friction modifiersystem based on inactive Sulfur [sic]chemistry. Exceed the requirements of:Cincinnati Milacron P-47, P-50, P-53 DIN51524 Part 2 Staticinemeter AGMA 250.04(EP) Schmidt (SKC) Inclined TribotesterDarmstadt Friction Rig APPLICATION: A premium quality, frictionperformance and multipurpose workshop oil,formulated with highly refined base stocks andfriction modifier system, based on inactiveSulfur chemistry. Recommended for thelubrication of all machine tool sideway andguides. Others uses are: As a hydraulic fluid inmachines such as grinder. As a industrial gearoil.

Speed and HorsepowerEstimator – Part 2

Ron Manley

[Following publication of the original article in SS21, the following information has been received. Ed.]

A couple of weeks after I had the putthe rule on my web site, with my suppositionsabout the author, I received an email fromCharles Ettien’s daughter. She and her brotherwere talking about their father with othermembers of the family and her son-in-lawdecided to do an internet search and he foundmy web site. She confirmed that her fatherwas the inventor of that slide rule and had beenvery disappointed that it never caught on withother drag racers. He seems to have been aremarkable man. He only finished 6th grade atschool (equivalent to the first year at secondaryschool in England), taught himself calculus andtrigonometry from text books in his 30s andafter retiring from his retirement job at LincolnHospital taught himself to become a locksmith.

BookwormNew additions to the UKSRC range of reprintscontinue to be added to our list. Recentadditions are so many that it is not practicableto detail them all. Wherever possible theUKSRC plans to make copies of any available

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Skid Stick Issue 22February 2006

instruction or other slide rule booklets andmembers are asked to loan copies in theirpossession so that our “library” can be made ascomprehensive as possible. The following is alist of new editions followed by details of somethe more interesting examples. All are inEnglish except as noted.

Nolan’s Range Finder TS “Emblem” Series, (3)

General # 1052 # 1071

VEB Mantissa (German), (2) Mono Rietz Darmstadt II

Jakar (3) Self-Teaching Manual #s 33/99 and 88 #s 11,22,29,33,55,66,77,88 and 99

Helix,“Top Precision” seriesCirculatorUnique, “Harfield Weight Calculator”Graphoplex (French), (6)

# 650#s 610,1600,1610,1694#s 1600,1614# 647#s 690,691,692#s 612,615,650,643

Hemmi (2)# P261#s P280,P281

Nestler (German), (2)Schul und TaschenrechenstäbeSchul-Rietz, Elemath

UTO (3)General 5 and 10 inch slide rulesRietz, Darmstadt & ElectroNavigational computer

Kent (Dutch) #s 7153,7153LL

Alro (Dutch)300D Type 100R & 200R

ClassicGeneral

AxelsonFactorule

Faber-Castell (German)#8/10

Faber-Castell#s 2/82 62/82

Aristo (German) (2)Commerz III 623Scholar 0903,0903LL,0903V5,0903V5-2

Aristo (French, German, Spanish, English)603 – 604

Aristo (4)Reel Data Calculator #40104Junior 0901Scholar 0903,0903LL,0903V50903V5-2 Aviat #s 610,613,615,617,618, & AviaJet 647

Concise (3)# 28# 57General

Blundell Harling Academy (3)GeneralEdition for WH SmithMode D’Emploi (F)

Br. Thornton (3)Edition 1967, 68, 69Edition 1971Edition 1973

Key to Palmer’s Computing Scale includingthe Time Telegraph by John E. Fuller, NewYork, 1846. The copyright of Palmer’sComputing Scale had by this time passed toFuller who had added the Time Telegraph, adisc calculator for determining days betweengiven dates. Only one page of this 72 pagebooklet relates to the Telegraph, the remainderbeing instructions for the Computing Scale.£3.50 inc. postage (UK).

A Method of Calculating a Table ofRadiographic Exposure Factors by Friel andSturdy. This booklet relates to the Friel-SturdyRadiographic Slide Rule made by the UniqueSlide Rule Co. of Brighton. Note – a smallportion of text is missing on page one. 20pp.£1.00 inc. postage (UK).

Other reprints available include instructions forP.I.C. Clementson Pipe Sizing Rule

(Water Pattern), £0.50p inc. postage (UK).P.I.C. “Brymay Pattern” Slide Rule

for Timber Calculations, £0.50p inc. postage(UK).

www.sliderules.org.uk4

Particulars and Instructions for use ofImproved Calculating Rule (A G Thornton).Probably the earliest slide rule instructionsfrom Thornton. 8pp give instructions for therule supplied by Thornton but made by Nestler.£1.00 post paid (UK). (QuoteThornton/Nestler when ordering).Particulars and Instructions of ImprovedCalculating Slide Rules (A G Thornton)Instructions and price list c. 1900. pp 27,includes instructions for the Perry slide rule.£2.50 post paid (UK). (Quote Thornton/Perrywhen ordering).

Musings 22Peter Hopp

Happy New Year and a belatedHappy Xmas this being our first SS of 2006. Itrust that all the excesses of the “fester” seasonhave left you intact, and that the New Yearfinds you all bright eyed and bushy tailed andjust itching to contribute something to one ofthe organs of your favourite slide rulecollecting organisation! Go on, you reallywant to write something for us, you made theNew Year resolution, and it now just needs thatlittle extra push to get the pen (?) out and geton with it! Well here is the unsubtle push.How can I help you any further? Just let meknow.

I was more than somewhatnonplussed at being honoured, together with anumber of other much worthier people, by theOughtred Society. As Colin said in the lastSkid Stick, it does seem odd to be honoured forsomething you enjoy doing. As he said, it iseasy to produce the stuff we do when we havean active and involved membership – thanksand long may it continue. The result of thedeliberations by the OS committee wasdeserving of a medal in its own right, beingelegantly resolved with an artistic anddelightful award that anyone can be proud to

display. I am extremely proud to have been sohonoured by fellow slide rulers – thank you!

When is a written article complete?A bit of a rhetorical question as I suppose it iscomplete when the author thinks it is, andwhen he has run out of things to write! Theproblem is that there is a temptation to hangfire with publication until one has “all theinformation” and, boy oh boy, one could waitan awful long time for that happy situation.My view has always been “publish and bedamned” with the result that I have often beendamned immediately after publication whensome new and vital piece of information comesto light from a very obvious source and onethinks “Oh Dash!” (Or similar!). The moral is:one does not know what one does not know,only, with any certainty, that one surely doesnot know everything! The next problem is thatas further information trickles in, then at somestage one has to update the previous article,and so we are back to the original question –when is an article complete?

Having started with a bit ofconvoluted philosophy, the next item is muchsimpler, how do we maintain the momentum ofannual International Meetings across threecountries – UK, Germany and Holland –without all gradually going into a steep spiraldecline and disappearing up our ownfundaments? The problem of Internationalmeetings, and to a smaller extent with our owntwice-yearly national (or local) meetings, isthat of attracting the punters. The localmeetings, with an attendance of around adozen, are fine as that size of meeting iscomfortable in some kind person’s house andwe do not have to start increasing our subs tocope with a “posh” venue and all that entails.When/if local meetings start attracting say 50%more punters then it will be a super problem tohave to sort out, but back to our InternationalMeetings – the problem here is similar, weneed to attract more people to keep upviability. Meetings in mainland Europe attractabout 50% more punters than UK meetings andthat immediately makes them more viable.Why and/or how do they manage to attractmore people? We do not really know, and Iwould be curious to hear from others why theythink that is the case, and indeed any ideas ofwhat we can do to improve. We (the editorialteam) have put it down to the “EnglishChannel” syndrome, i.e. the additional cost andbother of crossing La Manche is animpediment to our continental cousins fromattending. I guess without going into too deepdetail there is a much more basic question – Dowe want to have International Meetingsannually? When we have an answer to that we

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Skid Stick Issue 22February 2006

can continue by trying to see what would attracta higher percentage of our UK membership andthen more from across the water – all waters.

The images I presented at theInternational Meeting raised a pleasing numberof very positive comments - thank goodness!It must be said that with the recent (last 18months) increase in the number of picturesavailable via the web, pictures of “People andSlide Rules” are no longer rare. However,some images are rare, as they have not made itonto the web – yet! This means that I cancontinue to present you with three images ayear. I just must be careful to find the “good”ones. This cartoon (they are still rare) is fromwww.pluggers.com, a “Plugger” being definedas 90% of the world, i.e. those people thatcontinue to plug along despite whatever theworld throws at them, are slightly dinosaur ormaverick, and yet maintain a smile throughout.I’m sure you all know many “Pluggers”, Icertainly do. It was nice to see that “Pluggers”also used slide rules.

Science Museum Booksto Move

In SS 20 we reported that there wereproposals to split up the valuable collection ofbooks in the Science Museum on the groundsof economy. Whether as a result of theensuing outcry or not, a compromise seems tohave been reached and the following noticeappeared in the Daily Telegraph:

The Science Museum is to move fourfifths of its library out of London. to a new£2.5 million store in Wiltshire.

The museum had said it wasconsidering breaking up the 500,000-volume

library, which includes first editions ofGalileo, Newton and Einstein, because it couldno longer afford the rent to keep the library atImperial College, next to the museum.

In a deal to be announced, around100,000 of the most commonly used books andmanuscripts will remain on the Imperialcampus. The rest will go to a new store nearSwindon. [This is probably the site at RAF Wroughtoncurrently used by the Science Museum].

Ready Reckoners

Bruce O. B. Williams has an article inthe IEEE Annals of the History of Computing,Vol. 27, No. 24, on the subject of the principlesof reckoner design, development, usage, pricesetc.

Further details:http://doi.ieeecomputersociety.org/10.1109/M

AHC.2005.64

Spring Meeting

Once again Peter Hopp has kindlyvolunteered to host our next local meeting athis home in Bocking. Date: Sunday, May 14th.Starting at about 10.30/11.00, the usualarrangements regarding contribution to cost oflunch will apply. All are welcome but pleasegive Peter advance warning of your intentionto attend. The theme for our meeting iscircular (disc) slide rules so please share withus your interesting examples.

Peter Hopp 1 Dorewards Avenue

Bocking Braintree

Essex CM7 5LT01376 326132

[email protected]

Laboratory of MathematicalMachines in Modena, Italy

George Duckworth

The Autumn 2005 issue of the BritishSociety for the History of Mathematics, carriesan article by Andrew Ayres of the OpenUniversity on the above laboratory (MMLAB)at the University of Modena and Reggio Emiliain northern Italy.

The laboratory has some two hundredmodern replicas of historical mathematicalinstruments in its collection which areavailable to secondary school children to use

www.sliderules.org.uk6

and understand in the course of theirmathematical studies. The MMLAB alsoorganises travelling exhibitions visiting schoolsand shopping centres. It has also exhibited inParis with the aim of encouraging students andthe general public to understand theinstruments and the mathematical conceptswithin them.

The article does not include anyreferences to slide rules but among the itemsmentioned are Frans van Schooten’sellipsograph, Menaechmus’ oxytoma,Descartes’ hyberbolic lens cutting machineand Delaunay’s hyperbolagraph.

[www.mmlab.unimo.it]

MMLAB contd.Colin Barnes

As a result of the above, I contactedProfessor Mariolina Bartolini of the MMLAB.Sadly their collection does not extend toinclude slide rules but Professor Bartolini waskind enough to forward the image below asbeing the closest instrument they had, each leghaving a sliding extendable leg.

I had seen illustrations of this instrument inGalileo and the First Mechanical ComputingDevice, an article by Stillman Drake thatappeared in the Scientific American in 1976.Drake calls this the forerunner of the sector andsays that a non-calculating sector wasillustrated in a book on instruments printed inVenice in 1598. The instrument was devisedby Galileo’s friend Guidobaldo del Monte.Drake says: “Guidobalso’s sector was aconsolidation and improvement of two draftinginstruments that had been in use in Italy sincethe 1560’s. One was the ordinaryproportional compass, which is still in usetoday; it had points at both ends and a

moveable pivot. The other was the reductioncompass, with a fixed pivot, two fixed pointsand two sliding points at right angels to thearms.”

POLYGON IN CIRCLE shows atypical use of Guidobaldo’s instrument. Herethe problem is to inscribe a pentagon with sidesof equal length in a circle that has its diameterthe two endpoints of the instrument. With thatdistance established one measures the distancebetween the 5 on one scale and 5 on theopposite scale. This distance is the length ofone side of the desired pentagon.

Professor Bartolini also alerted me tothe website of Cliff Stoll who makes KleinBottles. Cliff uses a slide rule in theillustration of a bottle on his homepage andalso has a demonstration rule in his office, aKeuffel & Esser 4081-3 (about 2.2 meterslong). He rescued it from disposal from his oldphysics lab.

And Klein Bottles? I don’t know,they appear to be a three-dimensional mobeusstrip.

Klein Bottle and Slide Rulehttp://www.kleinbottle.com/

Voltaire’s Lucky Numbers

Voltaire famously described playingthe lottery as a “tax on stupidity” but this not

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Skid Stick Issue 22February 2006

prevent him making a fortune from it! In 1728the mathematician Charles Marie de LaCondarmine pointed out to him, a loophole inthe French government lottery. The prize onoffer was considerably greater than the sum ofticket sales, so Voltaire promptly bought all thetickets and scooped the pool with 800,000francs. I do not know what his initialinvestment was!

Memories of the RAFrancis Wells

I was also interested, as always, to see thelatest Skid Stick, especially the item about theuse of slide rules in the Royal Artillery duringthe First World War, which reminds me of atrue experience of mine (if you can be botheredto hear about it). In the winter of 1947-1948, i.e. thirty yearsafter the events recounted, I was doing mybasic training as the lowest form of life in theRoyal Artillery (21053066 Gnr. Wells, F.) onSalisbury Plain at a place called Larkhill. Ourbarracks were in fact a few hundred yardsnorth of Stonehenge, with the result that whenthat venerable monument is mentioned, mythoughts are not about prehistoric astronomy orengineering, or even about Druids andunwashed weirdos, but physical exercise(“ROUND Stonehenge, HAT the double. Go!”). Anyone trying to do that nowadayswould have to pay to get in and would stand agood chance of being run over on the A303,but petrol rationing was still on and it was justa sleepy country road in those days.

But to get back to slide rules, or rather nonslide rules, while there we had to take a coursein army mathematics, taught us by a lance-bombardier (acting) who was not exactly aleading light in the subject. Most of theproblems were triangulation in various forms,and there was an army drill for every type ofproblem, each drill consisting of taking a thickarmy-issue book of tables and looking up theappropriate straight logs, log sines, etc, writingthem down in a prescribed order, adding up theresults and looking up the antilog of the total. For some reason known only to the RoyalArtillery, we were not trusted to understand anegative characteristic (I had to look that wordup -- I remembered “mantissa”, but not that)and so instead of “bar one”, we had to put 9(10 - 1). We finished up with a log valuelooking something like 28.4567, which ofcourse is either an astronomical figure or total

nonsense. There must have been an army rulefor getting back to something more rational,but I forget what it was. I felt sorry in a wayfor the poor instructor. He knew as well as wedid that at least five members of the squad hadHigher School Certificates in Maths and hewas always on the lookout for piss-taking(which we never did -- it was just as much funto play things straight). One day he gave us a“problem” involving a 30-degree right-angledtriangle for which the answer could obviouslybe obtained by simple doubling. Most of uswrote down this answer and got on with thenext problem. When it came to correcting thework, there was a strange glint in the lance-bombardier's eye when he asked one of thesquad (scholarship in mathematics to aCambridge college) to give the answer. To oursurprise, when this came back “20”, he gave acry of triumph: “Aha! Got you there! Theanswer's 19.9999. I'm not havingapproximations in this squad.” Sure enough,when you do things the army way, the answeris 19.9999. Since the army is always right,especially when it’s wrong, he made us do thecalculation and arrive at 19.9999.

The decimal places are of course completelyunnecessary (let alone correcting an error of 1in the fourth place). Admittedly thecalculations were ostensibly intended to makesure that the shell landed on a precise spot orpreferably person, but most of the non-spatialvariables, like windspeed, air resistance oreven the strength of the propellant charge, wereall subject to margins of error ranging, in thosedays at least, from 2% to at least 25%. But trytelling that to the army.

For this and other reasons, one of us one daytimidly suggested to the lance-bombardier thatall this could have been done much faster andmore practically with a slide rule. Thediscussion didn't get very far because he hadnever heard of such a thing and clearly doubtedits existence, but he finally acknowledged thatthere might be something like it "up the road"and if so, by definition, it wasn't for "the likesof us". (By "up the road", he meant the Schoolof Gunnery, now the Royal School of Artillery,I believe, which was also located at Larkhill,but a few miles away). Anyway, the moral ofall this, in combination with the article, is thatthings in the army can go a long waybackwards in the space of 30 years. I wonderif this reminds you of dealings with theMinistry of Defence. The sad thing is that itwould have been useful for those in the squadunfamiliar with a slide rule to know, in the

www.sliderules.org.uk8

army or in after-life, how the thing works -much more useful in any case than learning adubious army drill.

O Ye of Little Faith

Francis Wells has also sent us theabove image of one of a number of calculationsheets found with a recently obtained FullerCalculator. The owner obviously had littlefaith in his new fangled instrument.

Age SurveyTom Martin

During the course of IM 2005 it wassuggested that a survey be made of the ages ofdelegates. The results of this exercise, whichare probably very much as one would expect,are given below. 38 responses, average age 62.5, range 38 - 85 If anyone wants to construct a histogram -

Age 35-40 1 40-45 2 45-50 3 50-55 5 55-60 4 60-65 8 65-70 7 70-75 3 75-80 3 80-85 2

Perhaps it would be interesting toextend this survey to include the fullmembership of the UKSRC. With this inmind, if you are not averse to divulging theinformation and are not included above, pleasegive your age to the Editor who will treat theinformation in confidence so that the figurescan be collated and published without namingnames.

People and Slide RulesRod Lovett

Peter’s talk on “People and SlideRules” at IM 2005 set me thinking. We oftenbemoan the lack of pictures from the past ofpeople holding/using slide rules but we don’tdo much about it here in the present. OK wetake lots of pictures of us looking at sliderules/collections etc. but hardly any of usactually using one. Before it’s too late I thinkwe should create a gallery of UKSRC membersactually using them. Having such a gallerywould be a useful addition to our web site andwould allow us all to put faces to names. I’msure that once the first 10 or so were up mostof us would be pleased/proud to be included. What do you think?

Please submit your images to me,Peter Hopp or Colin Barnes in either hard copyor electronic form.

[email protected]

Help and Information

Bruce Williams is investigating theuse of PAYE (pay-as-you-earn) slide rules butto date has only patent documents to workfrom. The following abstract is typical:

Carr GB573520

The slide rule is used in conjunction with a

calculating machine capable of multiplyingand dividing. It also has the possibility of asmall slide within the main slide.

Abstract Carr Computing-apparatus. CARR, A. B. Oct. 20,1943. A device for the computation of incometax on the pay-as-you-earn system comprises afixed scale A showing the gross wages for theweek. An index upon a slide B is positionedopposite a fixed scale F according to the codenumber of allowances. A scale C on the slideB, graduated to the right in black and varyingaccording to the two rates of taxation, thenshows the amount of tax to be paid oppositethe employee's gross wage. The scale B isgraduated to the left in red to show the rebate,if permissible, to be paid to the employee. A

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Skid Stick Issue 22February 2006

scale D enables adjustments to be made whenoverlap occurs between the two rates of tax.Scales G, H, J enable adjustments to be madeaccording to the tax and earnings of the severalprevious weeks, only part of the scales beingshown.

Does anyone have an example of arule of this type, instructions for use or otherdocuments that would help Bruce.

Please contact Bruce at:[email protected]

from Bill Thacker

Just before Christmas I went on a tripto Valkenburg in Holland and foundthis weird adaptation to a slide rule. Itappeared to start life similar to a common orgarden 10" Sun Hemi (the cursor is foldedbrass on two edges and celluloid) but withconversion tables on the back which relate tothe metal foundry trade starting withstandard imperial to metric equivalents, thendensities of metals in lbs. per cubic inch,weights of wood in lbs. per cubic foot, meltingpoints of metals, the relative weights ofcastings in various metals in relation tothe pattern weight in wood. These are all inthe English language and seem to be part of theoriginal manufacture. The face of the rulecannot be seen as it has glued on to it somenew scales, made from a heavy photographicpaper.

The A scale is labelled “Kilo p 000Bogen”, the B scale is undefined, C scale has“Bogengrösse in Centimeter” and the D scalehas “Gramm per qm”. The C scale increasesfrom right to left so is an inverse scale.

I have tried to translate this and itappears to be related to curvature and amountof curvature.

Could this rule be used for bendingmoments on beams etc? Any other theories?

[email protected]

[The logo, just visible on the left hand end ofthe slide, is clearly that of a “Classic” ruleand the data sheet on the back, as described byBill, is also that of a standard “Classic rule.Ed.]

Otis King. My occasional but ongoing interestin Otis King calculators has raised aninteresting point. When did they cease to benickel plated and become chrome plated?Whilst the serial numbers do not give adefinitive manufacturing date, sufficientreports of earliest chrome and latest nickelnumbers will help to narrow the gap.Remembering that the early prefix letters (A –D) were reused from about 1969, I would begrateful for reports of models from the earlierperiod, Serial No. and finish together with anyother relevant details. For those in doubt, thenickel finish is much duller than the highlypolished chrome.

Also can anyone provide a photocopyor scan of a set of instructions carrying theWhitton Precision name and address togetherwith the Serial No. of the calculator relatedthereto?

I would also like to have reports ofscale numbers used. I have details of scalesmarked 17, 24, 411, 412, 413, 423, 429 and430. I am aware of scales 422 and 424 buthave no details. Can anyone help fill gaps?

Colin [email protected]

Slide Rule MuseumMike Konshak

I have set up an ftp authorization to submit scans. This was asked for by Craig Kielhofer of the ISRG (US) and the Oughtred Society.============================in your browser: URL: ftp://sliderulemuseum.comthen enter when promptedUser ID: sliderulepswd: isrg06============================

That will pop up a folder that you candrag and drop into from your local folders.This is much faster than trying to email largefiles. I have 1 Giga byte available, so Iwelcome manuals (200 dpi or better) and scans(150 dpi or better). I'll combine all scannedsheets into a single pdf file, but if you have thecapability, I would appreciate the help in doingthat. My goal is to be a common site, withoutany commercial interests, and hopefully fill inthe gaps with the help from other collectors.The ISRG is going to send me large files tofree up their host space. Let me know how Iam doing, especially if I have made a statementor claim that is inaccurate in my encyclopediasection.

www.sliderules.org.uk10