126 Irrigation and Drainage 



and maize for 1879 are given as reported for the 10th Census for 

 the thirteen states: 



Bu. barley Bu. oats Bu. maize 



per acre per acre per acre 



Illinois 22.25 32.24 36.12 



Indiana 23.35 25.02 31.39 



Iowa 20.23 33.57 41.57 



Kansas 12.52 18.77 30.93 



Maine 21.81 28.76 30.99 



Michigan 22.1 33.93 35.3 



Missouri 19.01 21.34 36.22 



Minnesota 25.62 37.97 33.81 



New York 21.85 29.79 32.97 



Ohio 29.7 31.49 34.09 



Pennsylvania 18.57 27.34 33.37 



Vermont 25.36 37.57 36.46 



Wisconsin 24.68 34.43 33.71 



Mean 22.08 30.17 34.38 



If a comparison is made between these reported yields and 

 those which are given above as possible with the recorded rain- 

 falls, when a favorable distribution in time occurs, it will be seen 

 that the mean reported yields are only about half as large as the 

 computed ones, and as observed ones are in localities where the 

 distribution of rain in time and in quantity has been favorable. 



These small average yields, reported from so many states, 

 and agreeing so closely one with another, must be looked upon 

 as expressing conditions unfavorable to large yields, and condi- 

 tions which the best of management cannot hope wholly to 

 counteract. 



The facts are that we are here confronted with results which 

 are due, in a very large measure, to the long intervals between 

 effective rains, to which reference has already been made. This 

 uneven distribution is so general in its character that when 

 the yields over wide areas are brought together for comparison, 

 the small yields due to faulty distribution of rain so far outweigh 

 the large yields, where the amount of moisture has been just 

 right, that small averages are inevitable. Nor is this condition 

 of things strange ; for, since the rainfall is in no way controlled 

 by any factor operating to cause precipitation, either when it is 





