12 



PHYSIOGRAPHY. 



[chap. 



a mile of ground is represented there by the fourteenth part 

 of an inch. 



In most maps, except those on an extremely small scale, 

 an attempt is made to show something of the general 

 features of the ground, especially whether the country is 

 hilly or not. This is commonly effected by a system of 

 hill-shading, such as that represented in Fig. 3.^ If the 



^mmiic- /■ n t^^s^-y M im ' . n *. "^\ ''■»^l 



Fig. 3. — Hiil-shadiijg by means of hachures. 



ground is steep, the lines, or hachures, are drawn thick and 

 close together, so that the hilly spots become dark ; if the 

 ground is tolerably level the lines are thinner and farther 

 apart, and the general appearance of the map is conse- 



^ This figure is copied from part of sheet 59 of the one-inch Ordnance 

 map of England and Wales, and shows the physical characters of a 

 district in North Wales. The portion of the map here copied is a 

 square measuring two inches along each side, so that the total area 

 represented in Fig. 3 amounts to four square miles. 



