Sir Roderick Impey Murchison (1792-1871) was the first to describe the Silurian system and in 1845 was knighted for his services to geology. From 1826 geological mapping in Great Britain was under the control of the Ordnance Survey. In 1855 Murchison was elected Director-General of the Geological Survey. The maps set a new standard for accuracy in the field and here we offer his general map of England and Wales. Each is colour keyed along the upper left margin and identified. This example is the fourth edition with two pages of adverts for other cartographical works published by the firm Edward Stanford.