262 THE WHEAT DISTRICTS. 



summer ranges from 68 to 71, and the grain ripens 

 usually in July. In the extreme southern states May 

 is the harvest month, and the mean temperature of that 

 is from 67 to 70. In Virginia the wheat harvest 

 extends into June, and the mean temperature is from 

 63 to 65 for May, and from 68to 72 for June, while in 

 central New York the harvest extends into July, and 

 the mean temperature of the former month there is 64, 

 and that of the latter 69 ; and in Illinois, where the 

 wheat harvest ends in June, the temperature is below 

 70, while the temperature of May is from 60 to 62. 



As already intimated, many local modifications are 

 required in taking an account of the influence of 

 climate on the growth of wheat. A low temperature 

 for the growing months, which may be a rare exception, 

 will of course affect it. The summer of 1853 in Eng- 

 land, for instance, was about two degrees below the 

 average of mean temperature, and the consequence was 

 that the wheat crop fell off from a third to a half. July 

 and August of that year gave a mean temperature of 

 from 57 to 59, while 60 are required there to insure 

 a good harvest. The climate of our Pacific coast more 

 nearly resembles the climate of western Europe than it 

 does that of our own Atlantic coast. 



The following statistics of the mean temperature of 

 the months of growth and ripening of wheat and similar 

 grains, in wheat sections of this country and in Europe, 

 will be valuable for reference : 



