324 



SCIENCE 



[N. S. Vol. LI. No. 1317 



the coal direct into the furnaces of steam 

 boilers. Such methods offer the attraction 

 that they permit the recovery of by-products 

 that are lost with direct firing, and it is, there- 

 fore, disappointing to find that the com- 

 mittee's conclusions are adverse. They con- 

 clude that, in the present state of knowledge, 

 the direct burning of coal under steam boilers 

 forms the cheapest method of generating elec- 

 tricity on a large scale from coal, even when 

 the indirect processes are credited with the 

 revenue obtainable from the sale of the re- 

 covered by-products. What is still more un- 

 fortunate — from the point of view of those 

 who hope for an increased supply of home- 

 produced liquid fuel, as well as cheaper elec- 

 tricity from capital power stations with gas- 

 fired boilers — they make out that the advan- 

 tage of direct firing increases with rising costs 

 of coal and labor. — The London Times. 



NOTES ON METEOROLOGY AND 

 CLIMATOLOGY 



EAINFAI.L (and SNOWFALL) OF THE UNITED 

 STATES^ 



The Weather Bureau has just issued a re- 

 print from the Monthly Weather Review en- 

 titled " Seasonal distribution of precipitation 

 and its frequency and intensity in the United 

 States,"^ by Joseph B. Kincer. Three reviews 

 and abstracts are included in the reprint: 

 "Some characteristics of the. rainfall of the 

 United States,"^ by E. DeC. Ward ; " Ifew sea- 

 sonal precipitation factor of interest to geog- 

 raphers and agriculturalists,"* by E. M. 

 Harper ; and " The snowfall of the United 



1 Cf. notes on this subject in Science, July 19, 

 1918, N. S., Vol. XLVIII., pp. 69-72 (snow, 

 Science, February 11, 1916, N. S., Vol. XLIII., 

 pp. 212-214). 



2 September and October, 1919, Vol. 47, pp. 624^ 

 633, 695-696, 7 graphs, 30 maps — 13 in text and 

 17 f'uU-page lithographs. (For copies, apply to 

 "Ohief, U. S. Weather Bureau, Washington, 

 D. C") 



s Scientific Monthly, September, 1919, Vol. 9, 

 pp. 210-223. 



4 Science, August 30, 1918, N. S., Vol. XLVIII., 

 pp. 208-211. 



States,"^ by E. DeC. Ward. Since these three 

 papers are easily available, this note will cover 

 only Mr. Kincer's article and the graphs added 

 to the reviews of Professor Ward's two papers. 



Here are published, for the first time, reli- 

 able and detailed maps of the average rainfall 

 of the whole United States for each month. 

 The toijographic (hachured) base-map used 

 shows at once the close dependence of rainfall on 

 topography as it afEects precipitation of mois- 

 ture from the prevailing westerly winds. We 

 have long known of the marked spring and 

 early summer rainfall maximum in the prairies 

 and Great Plains; but these monthly maps 

 give us almost a moving picture of the wave 

 of rainfall which spreads northward and west- 

 ward as the warm southerly winds blow in day 

 after day from the Gulf of Mexico. From its 

 February position across east Texas, northwest 

 Arkansas and southern Illinois, the 3-inch 

 monthly rainfall line in March has moved 

 westward into Oklahoma, central Missouri and 

 northern Illinois; in April, to central Texas, 

 central Oklahoma, eastern Kansas and central 

 Iowa; in May, to the 101st meridian in south 

 Texas, across the Panhandle into northeastern 

 New Mexico, through western Kansas, west 

 central Nebraska, the Dakotas and northern 

 Minnesota, and in June stiU farther westward 

 in the central and northern Great Plains — in 

 Montana even to the Eockies. By June in the 

 southern Plains and by July in the northren 

 Plains the spring-time flood of moist air has 

 spent itself, and the rainfall lines are begin- 

 ning to retreat — eastward as the summer 

 passes, and southward as the coldness of the 

 oncoming winter renders much precipitation 

 impossible. The four maps of precipitation by 

 seasons suromarize this same mkDvement of the 

 isohyets. With such a series of maps before 

 one it is obvious that the Gulf of Mexico and 

 the open country to the north and northwest 

 allow our prairies and plains to be so produc- 

 tive. 



If the conditions year after year were like 

 those shown on these maps of average rain- 

 fall, we should not have been experiencing or 



3 Scientific Monthly, November, 1919, Vol. 9, pp. 

 397-415, map. 



