14 IRRIGATION. 



The measure of the water consumed may thus be con- 

 sidered as the measure of the capacity of the soil to fur- 

 nish its product) for it is clear that if this large quantity 

 of water was not supplied, the excessive product of grain 

 could not have been grown. If this conclusion be cor- 

 rect, we have at once a satisfactory explanation of the 

 hitherto strange fact that our best farmers, in no way 

 less skillful or less enterprising, and with no less fertile 

 soil, than the English farmers, can very rarely reach, and 

 still more rarely surpass a crop of 40 bushels of wheat 

 per acre, while in England 64 and 66 bushels are com- 

 mon with the best farmers. Taking the minimum quan- 

 tity of water, (viz. 727 Ibs.) evaporated for a pound of 

 grain, a harvest of 40 bushels of wheat per acre, would 

 consume, or pass through its leaves, an amount equal to 

 6 inches in depth, over the whole surface of the ground. 

 But this is not a complete statement, for the average re- 

 sult of a large number of experiments made in the pre- 

 vious year, and these results as well, prove that a crop of 

 wheat of 40 bushels per acre, may consume, or evapor- 

 ate, through its leaves, a quantity of water equal to a rain- 

 fall of over 17 inches ; for the less vigorous the growth, 

 the greater is the proportionate consumption of water, 

 and the yield which consumed 727 Ibs. of water for one 

 of grain, was greatly in excess of 40 bushels per acre. If 

 to this consumption of water is added the excessive 

 evaporation from the soil, con sequent upon the hot suns 

 and dry winds of our growing season, as well as the loss 

 through the passage of water over the frozen surface of 

 the soil, during our long winters, the totally inadequate 

 supply of water, for a maximum crop, under our now 

 usual conditions, is very evident. It is also evident, that 

 where crops can be grown by irrigation, and an ample 

 supply of water provided, there the success of the farmer 

 will be assured, and there the risks from untimely drouths 

 may be wholly avoided. It is also evident that every 



