136 MAPS AND THEIR MAKERS 



5° N. latitude and approximately 27° 30' E. longitude. The 

 northward bend of the Niger is conspicuous, but is carried 

 over 3° too far to the north, and the river truncated in the west. 

 In the east it is connected with what may be intended for 

 Lake Chad. In a note D'Anville states that there were reasons 

 for presuming, contrary to common opinion, that the great 

 river flowed from west to east. Elsewhere, except in the north, 

 the detail is almost entirely confined to the coastal areas. 



Another celebrated work was his map of India published 

 in two sheets in 1752, the best map of the sub-continent 

 before the work of Major James Rennell and the Survey of 

 India. 



D'Anville issued revised maps as the detail of contemporary 

 exploration came to hand. In 1761 they were published as an 

 atlas, and amended re-issues appeared until the early years of 

 the nineteenth century. He paid great attention to draughts- 

 manship and engraving — the lettering is clear and attractive — 

 and in this respect his maps are greatly superior to those of 

 Delisle, and to most of the products of his century. But perhaps 

 his greatest contribution to cartography was due to the degree 

 to which he carried out his own precept: "Detruire de fausses 

 opinions, sans meme aller plus loin, est un des moyens qui 

 servent au progres de nos connaissances". 



D'Anville's work was carried on by his son-in-law, Phillippe 

 Buache, who had a part in developing a more satisfactory 

 method of representing relief on topographical maps, a problem 

 which was receiving much attention at this time. On early 

 engraved maps, hills and mountains, scarcely differentiated, 

 were usually shown in profile, sometimes with shading to one 

 side. These symbols are often called *mole hills' or 'sugar 

 loaves'. The decisive step was the advance from depicting ranges 

 of hills or mountains as separate and isolated features to the 

 representation of the surface configuration as an integrated 

 whole. An interesting early example of this is the map of the 

 upper Rhine valley in the Strasburg Ptolemy of 1513. On this 

 the escarpments of the valleys are shaded, and the tributary 

 valleys are incised in the uplands, which, however, are shown 

 with a uniformly level surface. In countries such as Switzer- 

 land, the first attempts were more in the nature of oblique 



