WATER SOILS. 513 



Frincipes gencraux de vieteorologie, lS93,pj}. ]21). — This little book treats of the drought 

 in France in 1893, and attempts to show its causes. The latter are looked for out- 

 side the earth, especially in the sun and sun spots. — M. w. haukixgtox. 



The Sahara, H. Schiumer \ Paris: lS93,pp. 440). — A discussion of the Sahara from 

 the standpoint of its utilization for commerce and agriculture. The author dis- 

 cusses especially the causes of the existence of the Desert of Sahara, and finds that 

 those to which it has heretofore been attributed are not sufficient. After a thor- 

 ough discussion of the climate and its changes during the year, he decides that the 

 causes of the existence of the desert are purely atmospheric. He finds that a rel- 

 ative high pressure exists over the desert in winter, causing outflowing winds, 

 except in the extreme northwest, where there is a current of inflowing winds, 

 which must, however, cross the elevated Atlas range of mountains and thus be dried 

 up before it can attain the interior of the desert. In summer the desert is occupied 

 by a relatively low area of pressure, and while this causes inflowing winds from 

 moist areas outside, yet the low pressure itself is due to heat, and this heat decreases 

 the relative humidity of the inflowing air, until much precipitation is generally 

 impossible. He notes, however, that there is probably no part of the desert on 

 which rain never falls, but that in nianj' parts intervals of one or more years (some- 

 times as many as twenty), may pass without a rainfall. When in this region rain 

 does fall it is likely to be of a torrential character.* Over the south and over the 

 mountain region of the center there is a tolerably regular rainfall in mid and late 

 summer. Over the plains to the east and west of these mountains the rainfall is 

 irregular and only occasional. Along the northern margin of the desert, especially 

 in Algeria, a regimen of rainfall belonging to the Mediterranean is likely to occur, 

 giving rains in spring and in late autumn, while September is very dry. — m. w. 



HARRIXGTOX. 



Meteorological summary for August and September, 1894 {Mussacliusetla 

 Stale Sta. Bui. 55, p. 1). — Notes on the weather and tabulated summaries of observa- 

 tions on temperature, precipitation, and direction of wind. 



Meteorological observations at the Massachusetts Hatch Station, C. D. 

 Warner and F. L. Warrex (Massachusetts Hatch Sta. Met. Bui. 70, pp. 4). — Daily 

 and monthly summaries of observations at the meteorological observatory of the 

 station for October. The weather conditions are briefly discussed with reference to 

 their effect upon crops. 



Meteorological observations at North Dakota Station {North Dalcota Sta. Bpt. 

 1893, p. 6). — The maximum, minimum, and mean temperatures and rainfall for each 

 month of 1892 and 1893 are tabulated. 



Meteorological observations at South Dakota Station (South Dakota Sta. Bpt. 

 18DJ, pp. 8).—K repriut of Bulletin 31 of the station (E. S. K., 4, p. 243), 



WATER— SOILS. 



Nitrogen in rain water, R. W. Erwin {Utah Sta. Rpt. 1893, pp. 

 252., 253). — Determiiiatious of nitrogen as ammonia and as nitric acid 

 ill rain water collected at Salt Lake City during 1891, 1892, and 1893 are 

 reported. The average amounts of nitrogen in these different forms 

 sui)plied to an acre of land annually by rain water in Utah are calcu- 

 lated to be as follows: Mtrogeu as ammonia, 5.06 lbs. 5 nitrogen as 

 nitric acid, 0.3(3 lbs.; total, 5.42 lbs. 



Investigations of Courland soils, G. Thoms {Die erste Jciirland- 



ische Emiuete-Reise, pp. 8, and ]>ie zweite Jcurlandische EnqueteReise, 



pp. 28; excerpts from Land undforstic. Ztg., 1893, No. 28; 1894, iYo. 31). — 



Accounts are given of two journeys to investigate the soils of the 



12982— J^o. 6 3 



