510 EXPERIMENT STATION RECORD. [Vol.41 



Some characteristics of the rainfall of the United States, K. DeC. Ward 

 (Sd. Mo., 9 (.1919), No. 3, pp. 210-223).— This is a brief critical digest of the 

 more important literature on this subject, dealt with under the following heads : 

 Annual and monthly variability of rainfall, consecutive days with and without 

 precipitation, droughts, houiiy frequency of rainfall, heavy rainfalls in short 

 periods, instrumental records and noninstrumental evidence of secular varia- 

 tions in rainfall, and the climatologist's attitude regarding noninstrumental 

 evidence of climatic changes. It is stated that in the face of the conflictiug 

 testimony on the part of the experts, " the conservative climatologist may 

 A\ ell remain open-minded " on the question of noninstrumental evidence of 

 secular climatic changes. 



Rainfall regimes in Mexico, E. Lopez (Rev. Agr. [Mex.^, 4 (1919), No. 5-6, 

 pp. 213-218, figs. 2). — The regimes defined and discussed are subtropical calms, 

 simple tropical, tropical and monsoon, tropical and northern, maritime proper, 

 and maritime and northern. The importance of the matter from the stand- 

 point of agriculture is l)riefiy discussed. 



The relation of rainfall to configuration, C. Salter (London: Inst. Water 

 Engin., 1918, pp. 31, pis. 2, figs. 7; rev. in Nature [London], 103 (1919), No. 

 2579, p. 91). — This article reports a study based upon 35 to 40 years' observa- 

 tions by the British Rainfall Association at a large number of stations but at 

 altitudes as a rule below 1,000 ft. The physical process of rain formation is 

 discussed, and rainfall is classified according to the different circumstances 

 under which air is forced to ascend as convectional, cyclonic, or orographic, 

 the last named being caused by interference of rising land, which makes the 

 moisture-laden air rise. 



The first two types are but slightly affected by the configuration of the land. 

 Orographic rain is the predominant type in the British Isles, and the best 

 examples of it occur near the sea coast. It is not frequent in winter. Eleva- 

 tions of only a few feet near sea level affect the amount of rainfall. "The 

 rate of increase per 100 ft. of altitude varies within wide limits. It is lower 

 on slopes parallel to the prevailing winds than on slopes at right angles. On 

 fairly steep ridges close to the sea the maximum rainfall often occurs slightly 

 on the leeward side of the crest." The increase in such cases may be from 

 1.5 to 2 in. per hundred feet of altitude, but may be smaller when the slope 

 of the land is reduced. Rainfall diminishes steadily on leeward slopes of high 

 Innd. 



Fertilizing value of rain and snow, P. T. Shutt (Canada Expt. Farms Rpt. 

 1918, p. 19).— In the eleventh year of this investigation (E. S. R., 40, p. 724), 

 68 samples of rain and 35 samples of snow were analyzed representing a total 

 precipitation of 32.86 in. The total nitrogen supplied amounted to 6,259 lbs. 

 per acre. 



The period between blooming and ripening, J. Hegyfoky {Met. Ztschr. 

 [Brunstcick], 36 (1919), No. 3-4, pp. 79-84). — Observations in Germany on this 

 point with various trees, shrubs, and cultivated plants, and under varying 

 climatic conditions are summarized and discussed, particularly with reference 

 to the conditions causing variations in the length of the period from blooming 

 to ripening. 



SOILS— FEETinZERS. 



The classification of humus-free and humus-poor mineral soils of Sweden 

 according to their consistencies, A. Attekbekg (liitcnidt. Mitt. Bodenk., 6 

 (1916), No. 1, pp. 27-37, fig. 1). — The author offers a new classificatiou of the 



