&rm/rwnnmiwnnl 
4 
ied to represent these 
Variations appear on 
res are represented on 
in blue, the smaller 
md the larger streams, 
ag or blue tint. Inter- 
dry for a large part of 
and dashes. 
brown, which on some 
wing the effect of light 
rea represented, for the 
Lief and thus aiding in 
A contour line repre- 
(a contour) every part 
sea level. Such a line 
practice only the con - 
itude are shown. The 
e datum or zero of alti- 
’t contour would be the 
t. Contour lines show 
yalleys, as well as their 
it are far apart on the 
are close together indi- 
igether indicate a cliff, 
express altitude, form, 
’// 
/»' 
■)l 
theii* lower ends by a sea cliff, j 
abruptly at the valley in a stj 
gradually away and forms an 
ersed by a few shallow gullies 
features is represented, direct! 
sketch, by contour lines. J 
The contour interval, or the 
one contour and the next, is sti 
This interval differs according! 
mapped: in a flat country it ij 
mountainous region it may bej 
contour lines, every fourth or 
the others and are accompani] 
The heights of many points- 
surfaces of lakes, and bench m 
in figures, which show altitudes 
exact altitudes—those of benclj 
coordinates of triangulation sts 
issued by the Gfeological Surve 
Lettering and the works of n 
aries, such as those of a tatat 
ship, or reservation, are showi 
of different kinds and weight 
double lines, one of which is 
are shown by fine double li| 
dashed double lines, trails by 
Each quadrangle is designaj 
or prominent natural featur( 
the map are printed the r 
which maps have been publisj 
the United States have bee 
similar to the one on the < 
published. i 
r rV»ia triT~>ricrrJir>lllf*. TT13T) is th| 
