This sea chart displays the west coast of Africa along with the islands of St. Helena & Ascension. It is in the rarer FIRST STATE from 1648. It appeared in Sir Robert Dudley’s ‘Arcano del Mare’, the first printed English nautical atlas. It was superior to any previous work in that the charts illustrated the whole world, the first time any outside of Europe had been included. It was the first atlas to use Mercator’s projection throughout, and the earliest to show the prevailing winds, currents and magnetic deviation. Dudley improved upon the theory of navigating by the ‘Great Circle’, the shortest distance between two points on a globe. It would be the eighteenth century before cartographers used the projection consistently. During the great Dutch period not one atlas was produced using it. This chart of part of the Azores takes in the island of Corvo and a fictitious uninhabited island nearby. Shirley (2004) Atlases M.Dud-1a no. 82.