NATIONAL SURVEYS AND MODERN ATLASES 161 



been done in France, and to glance at the practice of other 

 countries in representing relief where it presents greater 

 difficulties than in Britain. In France the national survey is the 

 responsibility of the Institut Cartographique National, the civilian 

 body which has replaced the Service Geographique de TArmee. 

 The two main topographical scales are 1 : 20,000 and 1 : 50,000, 

 but neither of the current editions give complete coverage. 



In the nineteenth century, the Cassini series was replaced 

 by the Carte de I'Etat Major on the scale of 1 : 80,000. Originally 

 engraved, later photolithographed, this map has no contours, 

 but is heavily hachured. About 1900, a new series on the scale 

 of 1 : 50,000 was initiated. The original elaborate scheme has 

 been considerably modified, but progress has been slow. Some 

 220 sheets, out of a total of about 1,100, have been published; 

 owing to French pre-occupation with their eastern frontiers 

 most of the sheets fall in this zone. In fact the only medium- 

 scale map completely covering France is an enlargement of 

 the old 1 : 80,000 to 1:50,000. 



Since the reorganization and with the use of air photographs 

 and stereop lotting machines, progress has been somewhat 

 more rapid. The *Nouvelle Carte de la France au 50,000 eme' 

 is contoured in brown (black on rocks and blue on glaciers), 

 with contours at 5, 10 or 20 metre intervals, according to the 

 character of the ground. Relief is further emphasized by hill 

 shading both Vertical' and oblique from the north-west to 

 impart a plastic impression. This is obtained by photographing 

 a relief model suitably illuminated. Considerable attention is 

 paid to the vegetation cover; various types are indicated by 

 symbols in black with a flat green overprint. 



The national maps of Switzerland are distinguished by the 

 high standard achieved in the representation of relief, the result 

 of long experience and experiment. In 1938, the well-known 

 Siegfried map, which in its day set a good standard, was 

 replaced by a new series on the scale of 1 : 50,000, more accurate 

 and legible. It is very closely contoured, at 20-metre intervals, 

 with less obtrusive subsidiary contours at 5 and 10 metres in 

 brown, black or blue according to the surface. Summits, 

 precipitous slopes, rock falls and similar features are indicated 

 by fine rock drawing in black. Glaciers have contours in 



