Edgar Allen and Co - one of Tinsley's longest surviving businesses. Primary product is railway switching gear (http://www.railway-technology.com/contractors/track/eae/) accessed 7th March 2005. Northern-most building of the Imperial Works is first depicted on the 1923 25 inch to the mile map. Expansion south mostly complete by the 1973 OS. Imperial Works also had major building complexes to the west - now demolished, which began to appear around 1905. (William Edgar Allan was a member of the University of Sheffield Council from 1905 and was the benefactor for the first library building at Weston Bank). No legibility of earlier landscapes.