Revieics — Soil Surveys in the United States. 277 



ingredients, but also the physical characters of the soils. No one 

 since his time has paid so much attention to questions of economic 

 geology in Ireland as Mr. Kinahan, and he now records, sometimes 

 in very forcible language, his views on agricultural matters gathered 

 during an experience of sixty years of the soils and subsoils of the 

 country. 



YI. — Soil Sttkyets in the United States. 



THE Bureau of Soils of the U.S. Department of Agriculture issued 

 its seventh report on Field Operations during 1905 (Washington, 

 1907). The Bureau comprised Mr. Milton Whitney, the Chief, 

 a scientific staff of men, with forty-five Assistants in Soil Survey, 

 a chief clerk, and editor. During the year 1905, 21,289 square miles, 

 or 13,624,960 acres, were mapped, the average cost of the field-work 

 being reckoned at rather less than 9s. per square mile. Up to the end 

 of the year soil survey work had been undertaken in all but three of 

 the States, in four territories, and also in Porto Rico. 



The general results of the work demonstrate the very varied soil 

 and climatic resources of the agricultural domain of the country ; and 

 bring to notice additional soil-types adapted to the production of many 

 kinds of crops. Interesting examples are given of special adaptation 

 of soils to crops, such as tobacco, sugar-beet, sugar-cane, grape, peach, 

 cotton, as well as corn ; and tests have been made to determine the 

 manurial requirements of the more important types of soil. It is thus 

 coming to be generally recognized that the soil surveys are very 

 helpful to the farmers of any State, in indicating the adaptation of 

 soil to particular crops, and the means to be taken for their maintenance 

 and increase. 



That the soil -maps of the United States, like those of some 

 European areas, represent the subsoils rather than the actual and 

 constantly varying soils, is evident. Taking, for example, one of the 

 published soil-maps, that of the Everett area, in the north-west part 

 of Washington on the eastern shore of Puget Sound, we find it to 

 represent the characters (1) of mountainous uplands which rise to 

 1,800 feet, (2) of lower hills and bench-lands, which vary from 25 to 

 600 feet m elevation, and (3) of the valley region, with alluvial 

 bottom-lands and delta-flats, mostly not exceeding 20 feet in elevation. 



The mountain region (1) is stated to consist largelj^ of schists with 

 a backbone of diorite and granite, and to be separated from the lower 

 hills and benches in the area by an abrupt escarpment. The soils are 

 due partly to the effects of glaciation, partlj'to the residual weathering 

 of the schists and igneous rocks, which are exposed in numerous 

 places, sometimes extensively'. On the map, however, this mountain 

 area is coloured uniformly of one tint, according to the characteristic 

 soil, termed the Miami stony loam. 



The remainder of the area has a foundation of Tertiary shales, 

 sandstones, and conglomerates, which have been thrown into folds, 

 and outcrop occasionally along some of the streams. Elsewhere these 

 strata are buried beneath accumulations of till, and stratified deposits 

 of clay, sand, and gravel. 



