John Bartholomew (1805-61) was the first of the family name to join a business founded in 1784. The period of the late nineteenth and early twentieth centuries represented the height of the companies activity. The main influence of growth in the business was John George Bartholomew (1831-93). He was the inventor of layer colouring, first introduced in his maps in 1888. One of the firms first significant productions was the ‘Imperial Map of England and Wales’ derived from the Ordnance Survey. It is in effect a wall map divided into eighteen sheets as indicated by the borders which clearly indicate continuing sheets. The maps are typically detailed engraved on steel by Bartholomew who is also identified as the draughtsman. They are published by Archibald Fullarton. The map is drawn on a scale of four miles to the inch covering the whole of England & Wales. A brief study of the railways depicted showed for instance the Leatherhead to Horsham line under construction, it was to open in 1867. Beresiner ‘British County Maps’ pp. 52-3.