military operations, for it was made in connection with the parcelling of Irish lands among those who took part in the suppression of Irish rebellion. Again, the Scottish rebellion of 1745 led directly to a survey under Captain (afterwards General) Roy in 1747. It may be added here that in later cadastral work Ireland again took precedence of Great Britain: the six-inch survey begun in the former country in 1825 was nearly finished when that of Great Britain was undertaken in 1840. France continued to lead the way in cartography in the eighteenth century. The maps of G. Delisle (1675–1726) and of J. B. B. D’Anville (1697–1782) were not merely confined to local work; they also included the presentation of cartographical material for distant lands selected according to truer scientific criteria. Thus D’Anville’s map of Africa, though preserving a few old inaccuracies, did away with details which were purely imaginary, and boldly revealed the then practically complete ignorance of the interior by representing it almost wholly as a blank. We may contrast this with earlier maps of the continent. Thus Waldseemüller (1516) showed waterways running parallel with the west coast, from north to south, and showed no conception of the Congo. Gastaldi (1564) marked the Zaire (Congo); but this and an east-flowing river and a branch of the Nile all flowed from a great central lake, Zembere. Mercator established a definite parting of the Nile, the Zaire, and the east-flowing system, though his ideas were still far from the truth. English cartographers of the eighteenth century were inspired by the over-sea expansion of the empire to much good work beyond the home shores. Thus J. F. W. Desbarres in 1774–79 made use of the nautical surveys of James Cook and others in his Atlantic and North-American work. Thomas Jefferys produced West Indian and American atlases at the same time, and Aaron Arrowsmith founded a famous cartographical establishment, the work of which was carried on for a century. Mention is also due here of the work of Major James Rennell, who became surveyor-general of Bengal in 1763, and covered that territory in his atlas of Bengal (1779) on a scale of five miles to one inch, the work depending mainly upon route surveys and being, of its kind, extraordinarily good. The trigonometrical survey of England and Wales, already referred to as begun in 1784, owed its origin to French inspiration; for Cassini de Thury, who in 1740 had re-measured and found incorrect the work of J. and D. Cassini in France, represented the desirability of establishing a geodetic connection between Paris and Greenwich, and General William Roy was appointed to supervize the English work.