Measurement of Water 239 



dry hoeings, when flooding is again resorted to and 

 maintained until the crop is matured. 



THE MEASUREMENT OF WATER 



The man who has become expert in handling water 

 for irrigation really needs no means for measuring 

 1he amount required for the watering. His judg- 

 ment, based upon an examination of the soil, is more 

 reliable as to when enough has been applied than any 

 measurement which could be made. But as soon as 

 the same source of water becomes the joint property 

 of a community, or wherever water is sold to consumers, 

 means for measurement and division become indis- 

 pensable. For the user of water, too, a definite knowl- 

 edge of the exact amount he is putting upon a given 

 area of land is very important, until he comes to know 

 the needs of his land and of his crops for water ; be- 

 cause without this knowledge he is liable to run on 

 for years, using too much or too little water, leading the 

 water too slowly or too rapidly through the furrows, 

 causing waste by deep percolation or too shallow wet- 

 ting of the soil. If he knows that he has put the 

 equivalent of 3 inches of water upon his field and only a 

 quarter of the surface has been wet, it is certain that 

 his method has been faulty and a large part of the 

 water used has been lost. 



UNITS OF MEASUREMENT 



From the standpoint of the agriculturist, there is 

 no unit for the measurement of water used in irrigation 



