METEOROLOGY WATER. 7 1 8 



is srontly fiffected by favorable and unfavorable weatber conditions, and "th.it 

 tbe yield can be very closely approximated at tbe close of tliis critical period 

 by an exhaustive study of the weather conditions and crop yields of previous 

 years." Thus, charts showing the relation between the yield of corn in the 8 

 great corn-producing States in this country and the rainfall during June, July, 

 and August during 1888 and 1902 indicated " that the rainfall in July controls 

 the corn yield to a marked extent," and that by this means a very close esti- 

 mate of the yield of corn jtcr acre in the United States can be made by the 

 latter part of July. 



Charts which the author has prepared showing the departure of the average 

 lemi)erature, total rainfall, and crop yields from the normals by months, from 

 1870 to 1904, indicate a marked relation between the weather and the yield 

 of various crops. The charts indicate that for the best yield of oats June and 

 Jnly should be moderately cool and dry : for l)ark'y tbe summer should be warm 

 and dry; for potatoes a cool summer, with a fair amount of rain in .Tune and 

 July and a dry September; for hay abundant rainfall in April, May, and Juno. 

 Wheat, rye. and clover are affected l)y winter conditions such as alternate 

 freezing and thawing, sliort periods of severe cold, snow covering, etc., more 

 than by monthly temperature or precipitation. 



" The dates of blossoming of fruits depend to a marked degree upon the 

 temperature of March and April. In general iioor fruit yields have been pre- 

 cedetl l)y cold winters and good yields l)y comparatively mild winters." 



The law of sequence in the yield of wheat for eastern England, 1885-1905, 

 W. N. Shaw {Jour. A(/r. .S'c/., 2 {1!)07), Xo. i. j}p. 17-28, fi(/s. 2). — A shorter 

 article on this subject has already been noted (E. S. R., 18, p. 31.S). 



This article discusses in some detail the question of the relation between 

 yield of wheat ^and autumn rainfall, but more especially an apparent 11-year 

 I)eriodicity in yield as disclosed by a study of the yield of wheat for a selected 

 part of England during the last 21 years. While the relation between yield 

 of wheat and autumn rainfall has in recent studies not been found to be as 

 close as was at first indicated, it still appears that the autumn rainfall is in 

 a way the key to the subsequent seasons, and thus has an important bearing 

 upon the wheat yield. An examination of the meteorological and wheat yield 

 data shows that a wet autumn usually means a relatively dry spring and a 

 deficient crop and vice versa. 



Weather charts and reports, and their utility to the Indian agriculturist, 

 W. L. Dallas {Af/r. Jour. India, 1 (1906), No. J,, pp. J29-3S7, chart i).— This 

 article describes briefly the character of observations on pressure, temperature, 

 humidity, rain, wind, weather, and sea disturbance made at the government 

 observatories in India and attempts to show how w^eather charts and reports 

 may be utilized by tbe individual observer " in forming a conjecture as to 

 approachirig weather." 



It is pointed out that the charts " will be found most useful to those who study 

 them continuously and carefully and combine with them careful and systematic 

 observations of tiieir own n.ieteorological instruments and their local weather. 

 . . . AVhen considering what is the practical use to an agriculturist of weather 

 charts, giving as they do a representation of conditions of weather already 

 I)assed, it is necessary to acknowledge at once that the utmost they will permit 

 a careful observer to do is to make an intelligent anticipation of coming events, 

 an anticipation which may and indeed nmst frequently be incorrect, but which 

 on many occasions will not be without value." 



To-morrow's weather: How it is foretold, D. A. Willey (Sci. Amer., 96 

 (1907), Xo. '), pp. 108, 109, figa. 7). — The preparation of the daily weather map 



