412 Scientific Intelligence. 
Il. GeoLocy AND MINERALOGY. 
1. Sketches of the Physical Geography and Geology of Nebras- 
ka; by Samuet Aveuey, Ph.D., LL.D., Professor of Nat. Sci. in 
the Univ. of Nebraska. 326 pp. 8vo. Omaha, Nebraska, 1880.— 
These “sketches” contain a well-arranged and carefully prepared 
description of the region of Nebraska, as regards its topography, 
climatology, drainage and geology, and a general account of its 
ora and fauna. We cite the following facts from it: 
The State has a length (maximum) from east to west, of 413 
miles. The average elevation of the eastern half is 1,700 feet, of 
the western 2,612 feet. The mean elevation of the State is 2,312 
feet. The ascent for 100 miles west from Omaha is 5} feet a 
mile; for the second 100, 7 feet; the third 100, 74 feet; the 
fourth, 104 feet. 
up of t 
on an average, nine-fold (by his experiments) more absorptive of 
the water from rains. The water that falls on the hard original 
no 8 
thickness of the soil—of all depths to 200 feet in the less regions 
giv IS Sponge its great magnitude a 
Professor Aughey discusses well the facts relating to the 
and it e s that Richthofen’s wind-drift theory 
their respective plains in the same way. He mentions the occur 
rence of stratification, and in some parts of thin lamination; of 
transitions into or alternations with sandy beds; in its lower 
part, the occurrence of fresh-water as well as land shells, and 
various Other facts bearing on the question of origin. : 
of examining the silt after a flood on the Missouri four miles 
below Dakota City, and of obtaining, in 1871, of existing kinds 
brought down by the river, 35 species of land shells and 20 of 
fresh-water species. The lass of eastern Nebraska is over 3,000 
feet below its highest point on the west line of the State. But 
this height, so far as not due to a small eastward pitch in the 
waters, is accounted for by a change of level. ‘ 
The remains of life found in the less are, in addition to the 
molluscan, those of the rabbit, gopher, otter, beaver, squirrel, 
deer, elk and buffalo. Bones of the mastodon and elephant are 
fa>) 
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