. 
f 
The United States Geological Survey is mak 
topographic atlas of the United States. Thus wc 
progress since 1882, and its results consist of pul 
more than 40 per cent of the country, excluai 
possessions. 
This topographic atlas is published in the fo 
sheets measuring about 16.' .by 20 inches. Uu< 
piau adopted the country is - divided into quadi. 
by parallels of latitude and meridians of louj 
quadrangles are mapped on different scales, tin 
for each map being that which is best adapted ro 
the development of the. country, and consequent, 
standard maps are of nearly uniform size, they*. 
the lower inarg 
grapliic scales showing distances in feet, meters, i 
addition, the scale of the map is shown, by. a fracs 
a fixed ratio between linear measurements on tlx 
responding distances on the ground. For exa® 
, 715 ) means that 1 unit on the map (such as 1 inc 
meter) represents 62,500 similar units on the car 
Although some areas are surveyed and some 
piled and published on special scales for special 
standard topographic surveys mor the United Sta 
the resulting map£s have for many years been div; 
1ITED STATES 
tent these 
appea r on 
'Hunted on 
‘c smaller 
If .streams, 
1 inter¬ 
ne ' part of 
on some 
t of light 
1, for the 
aiding in 
ne repre- 
yery part 
IpU a line 
(the con- 
vn. The 
"0 of alti- 
|d be the 
tics show 
I as their 
t on the 
her indi- 
their lower ends by a. sea cliff. The h'li at the left tern 
t/ 
abruptly at the valley in a i sea 
gradually away and forms an inclined table-land that h 
ersed by a few On the map each of 
features is represented, directly beneath its position i 
Bkeicli, hv contour lines* 
. 
The contour interval, or the vertical distance in feet, b* 
► » 
one contour and the next, is stated at the bottom of eat h 
This interval differs according to the topography of th 
mapped: in a fiat country it may be tts small as 1 loot 
mountainous • -regioi 
contour hues, ev.'t-y, fatrlh i.r f i :f>h : heavito 
the others and.are aceompanad iy %i 
The heights of many points—such as road comers, am 
surfaces of lakes, and bench marks—are also given on th 
in figures, which show altitudes to the nearest foot only, 
exact altitudes—those of bench marks—as well as the ge 
coordinates of tria published in buj 
issued by the Geological Survey. 
Lettej if man are T 
aides, such as those of a State, county, city, land grant 
ship, or reservation, are shown by continuous or broke 
of different kinds and weights. Me wiled ■ » !.i ire sin > 
_ iJ*- min 
