This is one of the most important maps of Sussex, and one of the rarest. It is the first map of the county to be based on a trigonometrical survey. Although the title credits William Gardner and Thomas Yeakell as the mapmakers the influence of the Board of Ordnance was significant. The Master of the Board was the Duke of Richmond under whom the Ordnance Survey became fully operational in 1790. Both Yeakell and Gardner worked for it. Under the patronage of the Duke a map of Sussex was announced by Yeakell and Gardner in 1791. Unsurprisingly the map was a forerunner of the early Ordnance Survey maps. Published by William Faden this map won a Society of Arts Gold Medal in 1796. The ‘Proposals’ claim that ‘every farm-house, barn and garden will have its place. Every enclosure with the nature of its fence whether bank, ditch, pale or wall, will be delineated.’ This detail was the work of Thomas Gream. Kingsley (1982) 57; Rodger (1972) 459.