DUTY AXl) MEASUREMENT OF WATER. 



125 



Both gates are exactly on a level. The weir at the he;id 

 of each succeeding lateral is an exact duplicate. Five 

 weirs suffice for the six branches, the fifth one serving 

 for two, being at the last point of the division. The dis- 

 tribution of the water is so arranged that but one con- 

 sumer has water in a certain lateral at a time. Under 

 this arrangement the zanjero or ditch walker, starting at 

 the head of the main line with say six hundred inches of 

 water to be divided equally among the six laterals, goes 

 to the first weir and sets the gates in the ratio of five for 

 the main to one for the lateral, and so on, the gates in 

 the last weir being set equally open. Measurements to 

 ascertain the amount of water are made on the open weir 

 basis. Under this arrangement it will be seen that any 

 decrease and likewise any increase in the flow is equitably 

 divided among all parties on the system. 



Capacity of Pipes. To give a comprehensible 

 exhibit of pipe capacity and discharge, the following table 

 has been compiled : 



CARRYING CAPACITY GALLONS PER MINUTE. 



Some Simple Rules. A miner's inch of water is 

 equal to nine gallons a minute. 



Doubling the diameter of a pipe increases its capac- 

 ity four times. 



A cubic foot flowing a second of time is equal to 50 

 miner's inches, or 450 gallons a minute. 



