In 1762 the Royal Society of Arts announced a prize of 100 guineas for an accurate survey of any county. The first winner was this, Benjamin Donn’s map of the county of Devon. Published in 1765 it was the result of a five year survey which required measuring 6000 miles of roads and rivers etc. Along with the accepted inclusions may be found copper and tin mines, both Roman and Danish forts and usefully the distances between towns. With inset plans of Exeter, Plymouth and Stoke Town undertaken at the scale of 132 yards to an inch, as well as one of Lundy Island. Donn (1729-98) was a surveyor and mathematician at Bideford, Devon. In undertaking this survey he states he used both trigonometry and astronomy. The whole was beautifully engraved by Thomas Jefferys. Provenance: Beeleigh Abbey Books 1992; private English collection. Batten & Bennett 44; Ravenhill, W.L.D. (1965) Introduction to the facsimile.