I 
I 
t lan T2 per cent, of the country, exclusive of outlying 
si on*. 
l.i |). athu- is published in the form of map* <iu 
t ring .shout 161 by 20 inches. If icier die general 
adopted the country is divided into quadrangles bounded 
parallels of latitude and meridians of longitude. These 
I 
pack map being that winch is best adapted to general use in 
ie elopment of the country, and consequently, though the 
t 
lifierent sizes. On the lower margin of each map are printed 
phi scales showing distances in feet, meters, and miles. In • 
ition, the scale of tlie map is shown by a fraction expressing 
zed ratio between linear measurements on the map and cor- 
jondmg distances on the ground. For example, the scale 
means that 1 unit on the map (such as 1 inch, 1 foot,’ or 1 
er I represents 62,500 similar units on the earth’s surface. 
| ! * * - ■■ y i . - : - 
id and published on special scales for special purposes, the 
>dard. topographic surveys 1 for the United States proper and 
resulting maps have for many yearn been divided into three 
> 5 , differentiated as follows: 
Surveys of areas in which there are problems of great 
iar- mineral hie yi 
it, irrigation, or reclamation of swamp areas — are made with 
icicnt accuracy to be used in the publication of maps on a 
, . |t ; 1 iii-'b = oue-ball’ mile), with a contour interval <>f 
, or 10 feet. 
. Surveys of areas in which there are problems of average 
Lie importance, such as most of the basin of the Mississippi 
its tributaries, are mode with sufficient accuracy to be, used 
he publication of maps on a scale of ^ (1 inch = nearly 
| !- n\ if i. - contour nte cal of 10 tt -• v t. 
. Survoyp of areas in which the problems are of minor 
lie importance, such as much of the mountain or desert 
on of Arizona or New Mexico, are made with sufficient 
iracy to be used in the publication of maps on a scale nf 
(1 inch = nearly 2 miles), with a contour interval of 25 to 
i topographic survey of Alaska has been in progress si me 
8, and nearly 43 per cent of its area has now been mapped, 
'•ut 10 per cent of the Territory has been covered by reeon- 
1 i scale of ^co, or about 10 mi 
[h. Mo c t of the remaining area surveyed in Alaska has 
n mapped on a scale of but about 4,000 square miles 
been mapped on a scale of ^ or larger. 
I 
lids at riic western end of the group, have been surveyed 
the resulting maps are published on a scale of 
Id * 1 features shown on these nia oh may be arranged in thi ;e 
—(1) water, including seas, lakes, rivers, canals, swamp-, 
! ' In 1 • • •■■ 1 iof waiter; (2 relief, including moan win, 
I 
(works of man), such as towns, cities, roads, railroads, an 
boundaries. The symbols used to represent these features arc 
shown and explained below. Variations appear on some earlier 
maps, and additional features are rep resen ted on some spc'ial 
maps. 
All the water features are represented in blue, the smaller 
streams and canal* by single blue line^md the Larger gtream*, 
the lakes, and the sea by blue wateT lining or blue tint 
mittent streams- -those ^-hose beds are di'y for a large part of] 
the year—are shown by lines of blue imta and {hishex. 
Relief is. shown by coutout lines in brown, which on -ome 
friaps are supplemented by shad^^buwing the effect of light 
thrown from the northv^t aero® the Area re presen tad, for the 
purpose of givin^Pthe appearance of relief and thus {tiding 
the interpretation of the contour lines. A contour line nepre- 
aenbs an imaginary line on the ground (a contour) ’ever f trt 
ol which is at the same altitude above sea level. Such a 1: | 
could be drawn at any altitude, but in practice only the con-1 
tours at certain regular intervals of altitude are shown. The 
ar, the datum or 
fade being mean sea level. The '20-foot contour would be the 
shore line if the sea should rise 20 feet. Contour lines show 
the fcliupe hi Us, and valleys, as well as then 
die 
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f > 
C ny or 
vtlO-ge 
• Poor xtw '-• t or 
Roads and Rums Cliff (rood mOUar _ 
funlclings dwelling ruud private xyaxL 
Railroads 
Electric 
railroad 
Ham X» am with lock' Canallock O.SitowD^ ami Corner liar 
tpomi SOCQJOttMmB* V . OH CUSTJTCr.IUU. 
and recovetr.l comers 
[ecu If 
-te-ocih mark Cemetrsnio* Cttexdv School Poke >jv. 
otl TVKrTVUJI* 
TnoilimiQIlt fb1U>f*fain<an&T*y hetu'A 
ncm r\nn*-n, ir- •vr. J itn.t 
bf<tcv,-> ffyurvMi nv/Ziiiwi! 
fi&mrinuj 
i *»1 said 
.•** veils 
RELIEF 
<T>rtnUd m brown) 
5463 
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“N, 
S 
V 
1 httbLU-Ui diovp ( (MHoUffi 
n II>.i~n 3e.l. lfiVfiL lOvttouf* 
- .;r». i ■ ‘' '"Jr" 
■pr£n/r*it un bftJm/ 
Depression 
canfcijure 
JL*ve>? 
MreKUlH 
Falls and 
rapids 
Mme or 
quarry 
streams and 
ditrbes 
