616 EXPERIMENT STATION RECORD. 



uary 13; for the State —87°, January 13. Tlie annual rainfall at the station 

 was 46.6 in., for the State 37.82. The number of rainy days at the station was 

 124, for the State, 112. The prevailing direction of the wind was southwest 

 at the station and in the State at large. 



Water resources of Hawaii, 1912, C. H. Pierce and G. K. Laeeison {U. S. 

 Oeol. Survey, Water-Supply Paper 336 (1914), pp. 392).— This report describes 

 the geography of the Hawaiian Islands and presents results of measurements 

 of flow of certain streams and ditches in the Territory made during 1912. 

 Tables giving gage heights and daily and monthly discharges at each station 

 are given, also rainfall measurements. 



" The yearly rainfall of the Hawaiian Islands is extremely variable, ranging 

 from a few inches at several low-level leeward localities to more than 400 in., 

 usually at elevations above 2,000 ft. and on the windward sides of the islands. 

 Valleys lying on the same sides of the islands and within a few miles of each 

 other may have a variation in mean annual precipitation of several hundred 

 per cent. The rainfall may also vary greatly at different elevations in the same 

 valley." 



Quality of the surface waters of "Washington, W. Van Winkle ( U. S. Oeol. 

 Survey, Water-Supply Paper 339 {1914), pp. 105, pis. 2, fig. i).— This paper, 

 prepared in cooperation with the state board of health, describes the natural 

 and economic features of Washington, reports investigations of the surface 

 water supplies with particular reference to their value for domestic and indus- 

 trial use and for irrigation, and discusses denudation and the influence of 

 natural features. 



The conclusion states that "' the river waters of Washington are low in min- 

 eral content and are good for general industrial use or for irrigation. What 

 little suspended matter they carry is coarse and readily removable. The color 

 of some renders it advisable to purify them by coagulation and rapid sand 

 filtration rather than by slow sand filtration. 



" The Columbia River enters the State as a secondary saline water, but it 

 receives large additions of alkaline water and finally carries a water of mixed 

 type with a slight tendency toward primary alkalinity. 



'• The Cascade Mountain region is being eroded and dissolved at the rate of 

 1 in. in 500 to 900 years, and the rate of denudation near the summits is nearly 

 equal on both sides of the divide. The rate in the lower altitude is greater 

 on the western than on the eastern slope and greater in the Cascade intermoun- 

 tain region than in the Columbia plain.s. The rate in the basin of the Columbia 

 River is about 1 in. in 1,300 years. ... As denudation is not uniform through- 

 out the basin, but is most pronounced in the watercourses themselves, the rivers 

 nre deepening and widening their canyons and valleys. 



" No lakes are known whose waters are economically important as sources of 

 commercial salts. Waters from the coulee lakes of Washington contain a greater 

 proportion of common salt than the lake waters of southeastern Oregon, and 

 are therefore less valuable for recovery of soda." 



Colloids in water and sewage purification, M. F. Stein {Engin. Rec, 69 

 {1914), No. 19, pp. 524, 525). — The author discusses the peculiar properties of 

 colloids and their influence in settling basins, sand filters, and processes of 

 color removal. 



SOILS— FERTILIZERS. 



The separation of soil particles according to their specific weight and the 

 relations between plants and soil, J. Konig, J. Hasenbaumee, and R. Kronio 

 {Landw. Jahrh., 46 {1914), No. 2, pp. i65-25/).— Continuing investigations pre- 

 viously noted (P]. S. R., 30, p. 123), the authors report experiments on the 



