Harry Williams, Cartography * PROJECTIONS Lines of latitude and longitude, also known as parallels and meridians, form a GRATICULE or reference frame against which location…

Harry Williams, Cartography * THEMATIC MAPS A thematic map shows numeric or character data by colors or symbols. Data displayed in this manner is referred to as a theme.…

Harry Williams, Cartography * Elevation: Definitions: Elevation - height above some arbitrary datum; on USGS maps this datum is mean sea level (â0â feet). This datum was…

Harry Williams, Cartography * Surveying Techniques I. The USGS supplies 1:24,000 scale maps for all the U.S. But detailed topography at larger scales is rare and/or unavailable.…

Harry Williams, Cartography * INTRODUCTION Traditionally, geography has always been concerned with the question of "where things are" - in other words, it is a…