Bartholomew's Revised Half-Inch Contoured Maps - Cambridge (Great Britain, Sheet 20), 1946
Folding map, extending to approximately 32 inches by 22 inches (roughly 7 1/4 by 2 1/5th inches when folded), in stiff card covers (covers a little faded, lightly rubbed at edges). Map is clean, neat and clear. Map of the Cambridge area, scale one half inch to a mile, dating from 1946. Bartholomew's Half Inch Coloured and Contoured maps have a unique record among cartographical publications. The first sheets were brought out in 1856 with simple colouring by county. At the Paris Exhibition of 1878, Mr Bartholomew showed specimen sheets printed in layer or contour colouring. That system was eventually adopted for the whole publication series, which thus became the first ever topographical series in any country to use it. Based originally on the Ordnance Survey, it was latterly kept up to date by Bartholomew's.