182 



SCIENCE. 



[N. S. Vol. XIV. No. 344. 



most excellent means of education and instruc- 

 tion to the inhabitants by interesting them in 

 the local phenomena and the history of the 

 mountains and the rocks forming them. 



The physiography is by Cleveland Abbe, Jr., 

 and the geology by Cleoj)has C. O'Hara. The 

 county is in the western part of the State, em- 

 bracing parts of the Allegheny Plateau and the 

 Great Appalachian Valley. The rocks exposed 

 in the plateau district are of Carboniferous and 

 possibly Permian age and have been folded 

 into a flat northeast-southwest syncliue. The 

 upturned resistant Pottsville conglomerate 

 forms the eastern edge of the plateau in a 

 straight even-crested ridge, and the interior of 

 the plateau is composed of the softer overlying 

 rocks protected in the syncline to the west. 

 The Ridge district, embracing that part of the 

 county in the Great Appalachian Valley, is 

 composed of Silurian and Devonian rocks folded 

 into numerous open parallel northeast-south- 

 west folds, generally with steeper dips to the 

 northwest, but not overturned or overthrust. 

 Erosion has produced long parallel sharp- 

 crested ridges separated by narrow valleys. 



The remains of two physiographic plains 

 have been recognized in the topography. The 

 older, called the Schooley Plain, is preserved 

 only in the crests of the higher ridges. The 

 younger, called the Shenandoah Plain, is repre- 

 sented by the tops of low ridges and knolls 

 between 900 and 1,100 feet elevation along the 

 margins of the larger streams. This latter 

 I)]ain consisted of broad valleys between high 

 ridges which were not reduced during that 

 cycle of erosion. Two terraces of recent date 

 were observed in the stream gorges, marking 

 temporary halts in the downward cutting of 

 the streams. Some verj^ interesting stream 

 adjustments are described. The geologic his- 

 tory of the region is also interestingly pre- 

 sented. 



Among the mineral resources mentioned, the 

 more important are coal, fireclay, cement rock 

 and iron ore. Excellent steam coal has been 

 mined in the county for many years, and the 

 district is known as the Cumberland-Georges 

 Creek Basin. Several important beds are 

 mined and are distributed vertically through 

 the Pottsville and Coal Measures. The Biar 



Vein or 14-foot Vein occurs in the upper part 

 of the series, and is noted for its great size, 

 purity and fine steam quality. The report on 

 the economic products is by Wm. B. Clark, C. 

 C. O'Hara, R. B. Rowe and H. Ries. 



The soils of the county are represented on 

 the geological map, the subdivisions correspond- 

 ing to the divisions of the underlying rocks, but 

 a separate legend giving the descriptions of the 

 soils. Mechanical and chemical analyses of the 

 various soils are given in tabular form and their 

 value for agricultui-e is discussed. Clarence 

 W. Dorsey is the author. 



The hydrography and the remaining subjects 

 presented in the report, as well as the soils, 

 were surveyed in cooperation with branches of 

 the U. S. Government and the reports are pre- 

 sented hy members of the government corps. 



The volume is handsomely printed and illus- 

 trated with half-tone cuts in the same excellent 

 manner as in former publications of the Survey. 

 The atlas accompanying the report is a high- 

 grade lithographic production. The topo- 

 graphic map is that prepared by the U. S. Geo- 

 logical Survey in cooperation with the State. 

 The colors and patterns used on the geologic 

 maps are the same as those used by the U. S. 

 Government and the results obtained are very 

 pleasing. The publication by counties, how- 

 ever, makes it necessary to dissect the maps 

 awkwardly and print them on three sheets, 

 and makes the folio of unhandy size. 



George W. Stose. 



Washington, D.C. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The American Geologist for May contains a 

 biographical sketch of Elkanah Billings with 

 portrait by Henry M. Ami, Dr. J. B. Wood- 

 worth contributes an article on ' Cross-Banding 

 of Strata by Current Action.' He describes 

 micaceous bedding in the glacial sand near Lake 

 Walden and attributes its formation to the ver- 

 tical movements of the water about the crest 

 of a current mark. This is followed by ' A 

 Historical Outline of the Geological and Agri- 

 cultural Survey of the State of Mississippi,' by 

 E. W. Hilgard. This is followed hj 'Reviews 

 of Recent Geological Literature ' and ' Scientific 

 News.' The June number contains the follow- 



