Christopher Greenwood (1786-1855) was a surveyor from Wakefield, Yorkshire and moved to London in 1818. His brother John was also a surveyor and in 1821 they joined forces and with the distribution capabilities of George Pringle and Son, made an immediate impact with their series of large-scale surveys of many English counties. The early 1800s was a time of rapid change in the landscape with the burgeoning industrial revolution. Their surveys utilised the latest system of triangulation adopted by Colonel Mudge and his surveyors for the Ordnance Survey. Indeed, they were in open competition with them. The Greenwood maps were coloured as opposed to the more functional black and white Ordnance Surveys of the period. Rodger (1972) 47; Tooley Ch 18 in The Map Collector 17 pp. 22-6; Whittaker 349.