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 company’s influence. The main influence of growth in the business was John George Bartholomew (1860-1920). 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. 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 shows the completion of the Leatherhead to Horsham line which opened in 1867. Beresiner ‘British County Maps’ pp. 52-3.