SCALES OF MAPS. 
73 
Scales of Maps, 
(1) When the scale is one or more inches to the geographical mile, 
divide 72,996 (which is the number of inches in a geographical mile) 
by the scale, and the result will be the natural scale of the map, or the 
true proportion that a geographical mile on the map bears to a geo- 
graphical mile on the earth’s surface. 
(Example) Scale 4 inches to the geographical mile; 
4)72996 
18249 = 1 — nat. scale 
—“ 18: 49 
(2) When the scale is less than one inch to the geographical mile, 
multiply the number of inches in a geographical rode by the scale, and 
the result will be the natural scale of the map. 
(Example) 5 geographical miles to one inch: 
72996 
5 
364980 s —- uat. scale 
—— 1 364980 
(3) When a natural scale is given, the denominator of which is less 
than 72,996, and it is required to find the scale in inches, divide 72,996. 
by the denominator of the natural scale, and the result will be the scale 
of inches to a geographical mile. 
Example , Jj - = 72,996 -f-18,249 - 4 inches to a geographical mile, 
the scale of the map. 
(4) When the denominator of the natural scale is greater than 72,996, 
divide the denominator of the natural scale by 72,996, and the result will 
be the scale in geographical miles to one inch. 
Example gg= 364,980 -f- 72996 = 5 geographical miles to one 
inch, the scale of the map. 
