Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean (1855) (14757915584)

Identifier: reportsofexplora05unit_0 (find matches)
Title: Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean
Year: 1855 (1850s)
Authors: United States. War Dept Henry, Joseph, 1797-1878 Baird, Spencer Fullerton, 1823-1887 United States. Army. Corps of Engineers
Subjects: Pacific railroads Discoveries in geography Natural history Indians of North America
Publisher: Washington : A.O.P. Nicholson, printer (etc.)
Contributing Library: San Francisco Public Library
Digitizing Sponsor: California State Library Califa/LSTA Grant



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feet.1 The southern part of the Basin, however, althoughelevated, does not attain this altitude, but is considerably lower, as will be shown subsequently.The great elevation of the surface produces a great difference in the appearance of the boundingranges, compared with their aspect from the plains at their seaward base. The eastern slopeor ascent of the Sierra Nevada from the plateau is thus rendered very short, as compared withthat towards the Pacific. Along the Bernardino Sierra, the surface of the Basin reaches, in manyplaces, nearly to the summit of the chain, forming, in one instance, the crest of a pass. TheBasin may thus be said to be filled nearly to the brim. The surface thus elevated is not, as is generally supposed, a nearly level plain or plateau, butis rather a combination of slopes flanking the bounding mountains and all of the intermediateranges, ridges, or Lost Mountains. These slopes are of slight inclination, but of uniform rates 1 Report of Colonel J. C. Fremont.
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ELEVATION OF THE SURFACE SLOPES AROUND THE MOUNTAINS. 215 of ascent, and their length is determined by the distances between the ridges or frame-work uponwhich the materials forming them are deposited. When travelling on these extended slopes, the descent is scarcely perceptible, hut becomesremarkably distinct where a distant and projecting angle of the mountains throws the slopeoutward, so that it can be viewed at right angles to its direction of descent. When these oppor-tunities offered, the clinometer was used to measure the amount of inclination, and five degreesand six degrees was generally obtained as the result. The almost entire absence of vegetationsufficient to obscure the vision, and the clear air of that region, permit all the inequalities ofthe surface to be distinctly seen, even at great distances. The explorer of the Basin has, there-fore, peculiar facilities for studying its topography. The gently ascending or descending slopespermit rapid travelling, and the occasion