142 



THE BOOK OF NATURE STUDY 



Of the maps described above, the last, or six-colour form, is 

 undoubtedly the best for students to possess and use. Study 

 should first be devoted to the kind of features which have already 

 been dealt with on the higher scales, in order to attain familiarity 

 with the scale and the methods of representation of various 

 objects. But attention will soon be called to the new feature of 

 this map, its conspicuous representation of the relief of the country. 

 This is done by hachuring, the effect of which is, on the whole, 

 to give to the eye the appearance of relief. The method will be 

 most easily grasped if a bit of the map is photographed and enlarged 



(Fig. 40). Hachures 

 are lines drawn in 

 the direction in 

 which water would 

 run down the country 

 direct from higher to 

 lower levels. Where 

 the slope is steep 

 the lines are drawn 

 thicker, and closer 

 together ; as the 

 slopes soften finer 

 and thinner lines are 

 used, until over flat 

 areas, on very gentle 

 slopes, on the tops 

 o f plateaus, and on 



FIG. 4 0.-mchuring, enlarged three times from Fig. 39. the actua l summits 



of hills and ridges, there are no lines at all. This is usually so 

 well done that it is possible to follow out the drainage of rills and 

 storm waters down hill-sides into the larger valleys, and it will be 

 a useful exercise to work out on a part of the map this head- 

 water drainage, which is too irregular in its occurrence and on too 

 minute a scale for representation by blue lines on the printed 

 map. Walking and route-finding exercises may be also made 

 with the aid of this map, and especial attention should naturally 

 be directed to the working out of slopes along roads and paths. 

 While the Mchuring of a map is one of the best ways of picturing 



