Jonas Moore and his 'Mapp of the Great Levell'

The mathematician and surveyor Jonas Moore was elected FRS in the 1670s, as a result of his close involvement in plans for the founding of the Royal Observatory. At that stage he was employed as Surveyor General of the Royal Ordnance, but under the Cromwellian regime he had had a different kind of career as a surveyor, working for the company that successfully completed the draining of the Fens. This paper examines one of the products of that time: his sixteen-sheet ‘Mapp of the Great Levell’, printed in 1657 or (more likely) 1658. It was an impressive advertisement, for the drainage project, for the skills of its Surveyor, and for the increasing capabilities of the English map trade.