210 Irrigation and Drainage 



the Gattinara canal, water is provided which may be 

 applied at the rate of 5.289 inches per 10 days. But 

 under the Busca canal, where the utmost economy is 

 practiced and every drop is saved, the duty of water 

 is so much increased that one second -foot serves 106 

 acres, making a depth of water equal to 2.245 inches 

 every 10 days for the irrigation season. 



Bringing all cases cited by Smith into one table, 

 and expressing the second -foot in inches of water per 

 10 days, the following results are found : 



No. of acres 

 per sec. foot 



51.4 



45 

 106 

 100.6 



63 



90.6 



50.3 



70 



77 



This gives a general average for ordinary crops of 

 3.39 inches of water every 10 days and 33.9 inches 

 per 100 days, were it used at such a rate for so long 

 a period. 



In the rice irrigation of Italy, the amount of water 

 provided is said to be at the rate of 5.568 inches, 

 5.921, 3.412, 9.521, and 3.334 inches every 10 days 

 in as many districts, or an average of 5.55 inches per 

 10 days. 



