r 
ir is 
0''«;« (1 inch 
J ifll | fl -t Mi ( R'^ -Tca 
lie importance, sueh as most, of the basin of the Mississi i pi 
, its tributaries, are made with sufficient accuracy to be used 
jile 1 , with a contour interval of 10 to 25 feet. ' - 
•Surveys of areas in which the problems are of m nor 
♦ Isance maps on a scale of or about 10 miles to an 
been mapped on a scale of ~ or larger, 
jhe Hawaiian Islands, with the exception o tile small 
the resulting maps are published on a scale of 
ips—(1) water,.includi 
i, valleys, and other i'esiurea of le laud surface: (o) , oltir'e 
