1918] METEOROLOGY. 209 



the last killing frost in spring and the first killing frost in fall in Kentucky. 

 The average dates of frost, the average number of days in the growing season, 

 and the " standard deviations " from these averages are computed for each sta- 

 tion and consequent risks or probabilities determined. 



Predicting' minimum temperatures, J. W. Smith (U. S. Ho. Weatlier Rev., 

 45 {1917), No. S, pp. J/02-Ji07). — The importance of accurate methods of pre- 

 dicting mean temperatures in connection " with the development of orchard- 

 heating methods and the protection of general fruit and garden crops from 

 damage by frosts or low temperatures by heating, covering, or flooding" is 

 pointed out. The methods iised for this purpose are discussed. 



A brief historical note by C. F. Marvin is appended. 



Some field experiments on evaporation from snow surfaces, F. S. Baker 

 (U. S. Mo. Weather Rev., ^5 (1917), No. 7, pp. 363-366, figs. 2).— Observations 

 at the Utah Forest Experiment Station in the Mauti National Forest indicated 

 an evaporation of about 3 in. during the winter of 1915-16 out of a snowfall 

 equivalent to 21.91 in. of water. 



Mean annual rainfall of the United States, R. DeC. Ward (TJ. 8. Mo. 

 Weather Rev., 45 {1917), No. 7, pp. 338-845, pi. 1, fig. i).— The purpose of this 

 paper, which is based largely upon a new chart of average annual precipitation 

 prepared by the Weather Bureau, is to present a clear, simple statement of 

 essential facts regarding the rainfall of the United States from a broadly 

 geogi'aphical rather than strictly meteorological point of view. The article 

 discusses rainfall maps in general and the precipitation chart referred to in 

 particular, and summarizes the essential features of rainfall in the eastern and 

 Gulf provinces, the Great Plains, plateau provinces, and the Pacific coast. A 

 list of special and general references to literature bearing on the subject is 

 given. 



Damage by hail in Kansas, S. D. Flora and C. L. Bush ( U. S. Mo. Weather 

 Rev., 45 {1917), No. 7, pp. 359-861, figs. 2).— A study of the extent and dis- 

 tribution of damage by hail, briefly reported in this article, indicates that the 

 probability of damage from this cause increases toward the western portion of 

 Kansas, although both the average rainfall and the rainfall for the crop- 

 growing months in the western third of the State are less than half the aver- 

 ages for those periods in the eastern third. The causes of this increase in lia- 

 bility to damage by hailstorms in the drier, western part of Kansas remain to 

 be determined. 



Monthly Weather Review (U. S. Mo. Weather Rev., 45 {1917), Nos. 7, pp. 

 885-395, pis. 9, figs. 18; 8, pp. 897-488, pis. 10, figs. 7).— In addition to weather 

 forecasts, river and flood observations, and seisraological reports for July and 

 August, 1917 ; lists of additions to the Weather Bureau Library and of recent 

 papers on meteorology and seismology ; notes on the weather of the months ; 

 solar and sky radiation measurements at Washington, D. C, during July and 

 August, 1917 ; condensed climatological summaries ; and the usual climato- 

 logical tables and charts ; these numbers contain the following articles : 



No. 7. — Mean Annual Rainfall of the United States, with Notes on the New 

 Chart of Average Annual Precipitation (illus.), by R. DeC. Ward (see above) ; 

 Sea Breeze on Eastern Long Island (illus.), by E. S. Clowes; Influence of the 

 Sea on the Climate of Long Island, N. Y., by E. S. Clowes; Killing Frost and 

 Length of Growing Season in Various Sections of Kentucky (illus.), by F. J. 

 Walz (see p. 208) ; Relation between Temperature and Crops (illus.), by 

 D. A. Seeley (abs.) (see p. 208) ; Damage by Hail in Kansas (illus.), by S. D. 

 Flora and C. L. Bush (.see above); Scarf Clouds (illus.), by C. F. Brooks; 

 Some Field Experiments on Evaporation from Snow Surfaces (illus.), by P. S. 



