UL\J 4 T 
j lu 
9 L LI U k U- 
^ U UuUJj 
I 
Helent» ciectirctur^ 
V 
^6 Of §1^630 (f HI Oil 
5, or 10 feet. 
TT 
liiS"f^)n?iv 
v* n 
« i UL' 
j uT iliaTTo VJjJL C 
one-half mile), with a contour interval o 
/ 
2. Surveys of areas in which there are problems of averag 
iblic importance, such as most of the basin of the Mississippi 
id its tributaries, are made with sufficient accuracy to be use( 
i the publication of maps on a scale of (X iuch=nearl 
mile), with a contour interval of 10 to 25 feet. 
3. Surveys of areas in which the problems are ol mino 
ublic importance, such as much of the mountain or deser 
gion of Arizona or New Mexico, are made with sufficien 
curacy to be used in the publication of maps on a scale o 
6< - (1 inch = nearly 2 miles), with a contour interval of 25 t 
00 feet. 
j A topographic survey of Alaska has been in progress sine 
898, and nearly 37 per cent of its area has now been mapped 
bout 10 per cent of the Territory has been covered by reco 
aissance maps on a scale of K5 ^, or about 10 miles to aj 
ch. Most of the remaining area surveyed in Alaska h: 
een mapped on a scale of but about 4,000 square mil 
as been mapped on a scale of 
About half of the Hawaiian Islands has been surveyed, an 
Le resulting maps are published on a scale of 
The features shown on these maps may be arranged in thrJ 
:roups—(1) water, including seas, lakes, rivers, canals, swam 
Ind. other bodies of water; (2) relief, including mountai 
! *11 11 . 1 __ A ^ vxi* /^A • / Olllh 
dills, valleys, and other features of the land surface; (3) culm 
works of man), such as towns, cities, roads, railroads, ai 
