316 MANUAL FOR NONCOMMISSIONED OFFICERS. 



iru= ■ii.r==7^%=4r, in all of which different ways the slope 

 can be expressed. 



270 



On a good many contoured maps a figure like this will be 

 found in one of the corners : 



I I t 2 i 3 r4 i^vj 



On that particular map contours separated by the distance 



■ ••' 



■_ ' « 



on the vertical scale show a slope of 1° ; if separated by the 



distance | C § they show a 2" slope, etc. A slope of 1' 



is a rise of 1 foot in 57. To use this scale of slopes, copy it on 

 the edge of a piece of paper just as you did the scale of dis- 

 tances and apply it directly to the map. 



You will notice that where the contours lie closest the slope 

 is steepest ; where they are farthest apart, the ground is most 

 nearly flat. 



It has already been set forth how contours show height and 

 slope ; in addition to this they show the shape of the ground, 

 or GROUND FORMS. Each single contour shows the shape at its 

 particular level of the hill or valley it outlines ; for instance, 

 the 880 contour about the penitentiary shows that the hill at 

 that level has a shape somewhat like a horse's head. Simi- 

 larly, every contour on the map gives us the form of the 

 ground at its particular level, and knowing these ground 

 forms for many levels we can form a fair conception of what 

 the whole surface is like. 



