SOILS — FERTILIZERS. 709 



the streams of the Great Basin, includiug the Wasatch Mountains, the Hum- 

 boldt Sink, and the Sierra Nevada drainage areas, and the Great Basin drain- 

 age in Oregon. 



Well-drilling' methods, I. Bowman ( XJ. S. Geol. Survey, Water-Supply Paper 

 No. 257, pp. 139, pis. 4, figs. 25). — This paper is based upon ground-water in- 

 vestigations in the eastern United States, extending over a period of 3 years, 

 and including actual observations on well drilling, supplemented by one season's 

 observations in the South and Middle West. The paper contains a general 

 account of underground waters of the Tnited States; water, oil, and gas-bearing 

 formations ; the history of well-drilling ; and the distribution of drilled wells. 

 Different methods of well drilling are described, with a discussion of some 

 special features of well construction and general estimates of the cost of well 

 sinking. 



Pond fertilizing', Kuhnert (Mitt. Deut. Lanclw. Gescll., 25 {1910), Nos. 6, 

 pp. 77-81; 10, pp. 151, 152; ahs. in Wasser u. Abwasser, 3 (1911), No. 10, p. 

 Ji26). — The author maintains that it is profitable to use artificial fertilizers in 

 fish cultvire, and recommends that Thomas slag and kainit, each at the rate of 

 about 534.4 lbs. per acre, and sodium nitrate at the rate of 178.1 to 267.2 lbs. 

 per acre be used on fish ponds. 



Sewage sludge and its disposal, A. B. Ogden (Surveyor, 38 (1910), No. 983, 

 pp. 690-694)- — This paper discusses various methods of sludge disposal, but 

 gives particular attention to its utilization as a fertilizer. 



Analyses of sludge from different sources and results of experiments are 

 cited to show that the fertilizing value of sludge is well above that of ordinary 

 barnyard manure. The author describes methods of handling the sludge so 

 that it can be easily used by farmers without creating a nuisance. He urges 

 all those who are interested in agriculture or have to deal with sewage disposal 

 to aid in promoting the use of sewage sludge as a manure and thus restore to 

 the land the fertilizing material which has been taken from it. 



SOILS— FEKTILIZEES. 



Soil productivity, T. C. Chamberlin (Science, n. ser., 33 (1911), No. 8^1, 

 pp. 225-227). — This is a review of a fuller discussion of the subject of secular 

 maintenance of soils before the Geological Club of the University of Chicago, 

 January 9, 1911, which attempted to show that in view of the vast age of 

 productive soils there must be some eflicient natural process for their main- 

 tenance. Among the active factors in this process to which attention is called 

 ai-e the transporting and mixing action of wind and water, the progressive for- 

 mation of soil particles from the underlying rocks, the movement of water 

 in the soil, and the activity of micro-organisms. It is shown that although the 

 total loss of certain soil constituents in the drainage is large, there is a tend- 

 ency toward the accumulation of some of the constituents in the surface soil. 



Analyses are cited to show that in the larger proportion of cases the percent- 

 age of phosphoric acid is higher in surface soils than in subsoils, but that the 

 percentage of potash is lower. Some of the phosphatlc and potash compounds 

 are to be grouped with silica, alumina, and ferric oxid as the rock elements that 

 tend to stay in soils, while soda, lime, and magnesia compounds are more likely 

 to be carried away in the drainage. 



It is pointed out that plant growth cooperates with capillary action in con- 

 centrating certain soil constituents in the surface soil. 



The practice prevailing in certain parts of China of carefully saving and 

 utilizing all animal and vegetable refuse and returning it to the soil is referred 

 to as showing the possibility of maintaining a high productiveness without the 



