208 EXPERIMENT STATION EECORD. . 



The influence of meteorological factors on the yield of grain in the 

 Province of Bologne, G. Azzi (Trudy Sclsk. KJioz. Met., Xo. IJf (1915), pp. 

 19-47, fig. 1). — Studies made according to the Russian method of determining 

 critical periods in plant growth are reported, the results showing that the criti- 

 cal period for wheat as regards rainfall occurs during the two ten-day periods 

 immediately preceding heading. If, during the first of these ten-day periods, the 

 precipitation is not less than 30 mm., or if this period is dry and during the pre- 

 ceding period the rainfall was not less than 60 mm., the probability of agricul- 

 tural yield is excellent even if no more rain falls iintil autumn. 



Meteorological record for 1912, R. Withycombe (Oregon Sta., Rpt. East. 

 Greg. Sta., 1911-12, pp. 32, 83). — A summary by months of observations on tem- 

 perature (maximum, minimum, and average), precipitation, cloudiness, and 

 wind at the substation at Union during 1912 is given. The total precipitation 

 for the year, 17.74 in., was about normal for the region. 



Climate and meteorology [of Canada], R. F. Stupart (Canada Yearbook, 

 19H, pp. 128-139). — The main climatic and meteorological characteristics of 

 the different provinces of Canada are noted and tables of temperature and pre- 

 cipitation at various places in the Dominion during 1914 are given. 



The temperature of western and equatorial Africa, R. CufDEAU (Compt. 

 Raid. Acad. ,Sci. [Paris], 161 (1915), No. 5, pp. 106-109) .—A\ai\ahle data on 

 this subject are collated and analyzeil with reference to different regions in this 

 area. 



Atmospheric pressure in western and equatorial Africa, R. CHUDEAtr 

 (Compt. Rend. Acad. Sci. [Paris], 161 (1915), Xo. 12. pp. 351-354; abs. in Rev. 

 Sci. [Paris], 53 (1915), I-II, No. 19, p. 479).— The data obtained from 13 sta- 

 tions are suunnarizetl showing tlio mean, monthly, and annual pressure with the 

 diurnal variation. 



The distribution of rainfall in western Africa, H. Hubert (Compt. Rend. 

 Acad. Sci. (/'r/r/.s). ICO il'.il.;), Xo. /.s\ /»/). 606-60H) .—Th\f> article deals briefly 

 with the sources and types of rainfall of this region and the phenomena which 

 control it. It is held that in general the distribution deiiends upon the dis- 

 placement of the zone of equatorial calms. 



Electric niagaras, A. Beckertch (Jardin, 28 (1914), ^^o. 657, pp. 203-205, 

 figs. 2; 29 (1915), Nos. 664. pp. 272, 273, figs. 2; 665, pp. 281-283, fig. 1; 666y 

 pp. 290. 291). — This article discusses briefly the tlieories of the formation of 

 hail, the principles of construction of the towers used for re<lucing the electric 

 tension of the clouds and thus dispersing hailstorms, the action of these towers, 

 and the question of tlieir efficiency as means of hail protection. 



The general conclusion is that past experience with this means of hail protec- 

 tion is not conclusive and that the whole question of hail formation and hail 

 protection needs further investigation. The lines along which this investigation 

 should be pursued are indicated. 



A new chemical hygrometer, E. K. Rideal and A. Hannah (AnaJyst, 40 

 (1915), No. 467, pp. 4S-o4, figs. 3; ahs. in Intcrnat. In-^t. Agr. [Rome], Mo. Bui. 

 Agr. Intel, and Plant Diseases, 6 (1915), No. 4, pp. 439, 540).— What is stated to 

 be a simple and accurate means of measuring the moisture content of the air, 

 based upon its absorption by sulphuric acid, is described. 



Bacteria in city, country, and indoor air, W. W. Browne (Science, n. ser., 

 42 (1915), No. 1080, p. .557).— This is an abstract of a paper presentetl at the 

 recent meeting of the Society of American Bacteriologists which reportetl re- 

 sults of bacteriological examinations of 134 samples of city air, 85 of country 

 air, 87 of oflice air, and 47 of factory air. 



It was foimd that the number of bacteria was larger and the fluctuations 

 greater in the air of occupied spaces than iu that of open spaces. The micro- 



