40 
The foregoing maps enable one to study to advantage the 
great features of continental relief. Among those that may be 
noted are— that the continents in general have elevated moun- 
tain borders and a low or basin-like interior; that the highest 
border faces the larger ocean; that the lines of greatest elevation 
are placed outside the center; that all the gentle slopes descend 
toward the Atlantic and the Frozen Ocean, all the steep ones 
toward the Pacific and Indian Oceans; that the elevations go on 
increasing from the poles to the tropics. 
7. — Relief map of the United States. Horizontal scale 
85 miles to i inch. Vertical scale 36 times the horizontal. 
8 . — Relief map of the United States and the Gulf of 
Mexico, modeled on a section of a globe i 6 j 4 feet in diameter. 
Horizontal scale, i inch equals 4 miles. Vertical scale, i inch 
equals 8 miles. 
Note that the true outlines of the continent extend much 
beyond the present coast line and properly include the West 
Indies. 
9. — Relief map of Massachusetts, from maps of the 
United States Geological Survey and the Topographic Survey of 
Massachusetts. Horizontal scale, i inch equals 4 miles. Verti- 
cal scale, I inch equals 4,000 feet. 
No. 10 .— Relief map of Connecticut from maps of the 
United States Geological Survey and the Topographic Survey 
of Connecticut. 
No. 11.— Relief map of Northwestern Illinois including 
Cook, Du Page, Will and eighteen adjoining counties. The 
course of the Chicago Drainage Canal is shown. 
No. 12.— Relief map of the Yosemite Valley from surveys 
made by C. King and J. T. Gardner. Scale, i mile equals 
4 inches. 
No. 13.— Relief map of Yosemite Valley from surveys made 
by Captain of Engineers, George M. Wheeler, U. S. A. Scale, 
I inch equals 1,000 feet. 
No. 14.— Relief map of Yellowstone National Park, showing 
Canons of the Yellowstone and Madison rivers, etc. Horizontal 
and vertical scale, i inch equals i mile, or i. 63360. 
No. 15.— Relief map of a part of Mount Desert Island. 
Maine. Scale, i to 40000. 
