35 
colored to show geological formation. Horizontal scale, i in. 
equals 4 miles, or 1:253440. Vertical scale, 1:126720. 
No. 28. — Relief map of the Grand Canon of the Colorado 
and the cliffs of Southern Utah, colored to show geological for- 
mations. Horizontal scale, i in. equals 2 miles. Vertical scale, 
I in. equals 5,000 feet. 
No. 29. — Relief map of Eureka District, Nevada, colored to 
show geological formations. Scale, i in. equals 1,600 feet. 
No. 30. — Relief map of Mount Blanc. Horizontal scale, % 
in. equals i mile. Vertical scale, 1 % in. equal i mile. 
No 31, — Relief map of Mount Taylor, New Mexico, showing 
geological formations. Scale, i in. equals i mile. 
No, 32, — Relief model of Leadville and vicinity, dissected to 
show geological structure. Scale, i in. equals 800 feet, or 1:9600. 
No, 33. — Same as above, undissected. 
No, 34, — Contour map, in relief, of Washoe mining region, 
50 foot contours. Scale, 1:20000. 
No. 35. — Geological relief map of Blair, Bedford and Hunt- 
ingdon counties, Pennsylvania. A portion dissected to show geo- 
logical structure. 
No. 36. — Profile relief map of the Sentis Mountains, N. W. 
Switzerland, showing mountain contour and geological structure. 
No. 37. — Relief map of the high plateaus of Utah, colored to 
show geological structure. Scale, i : 1680000. 
No. 38. — Relief map of the Drainage basin of the Arkanas 
river in Colorado, showing the relations of the catchment basins 
to the reservoir sites and irrigable lands. 
No. 39. — Model showing irrigation by ditches and furrows 
on steeply sloping fields. 
Nos. 40 and 41. — Relief maps of Mount Shasta showing 
topographical and geological features. 
Nos. 42 and 43, — Relief maps of the Chattanooga District 
showing topographical and geological features. Note how, by 
folding and erosion, the formations originally overlying one 
another have been exposed so as to succeed one another laterally. 
No. 44, — Relief map of New Jersey showing topographical 
and geological features. 
No. 45 — Relief map of Kentucky showing topographical and 
geological features and location of principal coal fields. 
