314 



Irrigation and Drainage 



A B 



Fig. 73. Aermotor 14-inch reciprocating pump used by windmill. 

 A, pump ; B, piston head and suction valve. 



of the day. The lines of numbers opposite the name of the 

 month express the total number of miles of wind for the hour 

 of the day at the head of the column, while the other lines ex- 

 press the number of times the tank was emptied during each hour 

 of the day. In the footings of the table, the upper line is the 

 total number of miles of wind during each hour of the day for the 

 full year; the second line is the total number of tanks emptied. 



