ABSTRACT
Map Y is one of a small number of copies of William Smith’s 1815 map A Delineation of the Strata of England and Wales with Part of Scotland that are now known to have been made after he was awarded the Wollaston Medal in 1831. These copies therefore postdated the publication of his reduced scale version of the great map in 1820, and of his four county maps of northern England in 1824. Map Y made changes to the strata on the English side of the Border from how they had been portrayed on all earlier copies of the 1815 map. Changes of outcrops were made between the colliery village of Canon-bie, just inside Scotland, and the hamlet of Bewcastle, ten miles across the Border in Cumberland. The addition of geological contact lines to Map Y for these added outcrops are evidence of transferring information from the county map to Map Y. Changes made to Map Y in Northumberland provide clues for copying from the northern county maps, but firm evidence of that having happened is harder to find in that neighbouring county. 
