124 IRRIGATION FARMING. 



This pen is one of two arms attached to a revolvable 

 shaft, the other arm being in the form of a segment of a 

 gear. This segment meshes with a small pinion secured 

 to a shaft carrying a grooved pulley. Over the grooved 

 pulley a cord is passed, carrying at one end a float which 

 rests upon the water to be measured, and at the other end 

 a weight -which nearly counterbalances the float, keep- 

 ing the cord tight. As the water rises and falls the float 

 rises and falls with it. This fluctuation causes the cord 

 to revolve the grooved pulley over which it passes ; the 

 small pinion being fixed on the same shaft as the pulley 

 revolves with it, communicating its motion to the seg- 

 mental gear, which being attached to the same shaft as 

 the pen, both will revolve together; and the pen, being 

 in contact with the dial, will trace a mark upon it, leav- 

 ing a graphical record showing the days, hours and min- 

 utes in one direction, and feet and inches in another. 



A California Weir System. It often happens 

 that there is great trouble in a canal system in dividing 

 the water equitably among a number of irrigators, patrons 

 of the ditch. Consumers are expected to bear their pro- 

 portion of loss by seepage and evaporation between the 

 head of the main canal and their respective gates. This 

 loss is a varying one, being so great on a hot day that if 

 each gate is set to take its quota without shrinkage, the 

 man at the end of the system seldom has enough water 

 to drink. The West Highlands water company in San 

 Bernardino county put in a system of weirs which will 

 completely avoid this difficulty. Their main ditch is one 

 mile in length, with six lateral branches, each the same 

 length. At the head of the first lateral the ditch ex- 

 pands into a large cemented basin having two outlets, 

 one opening into the main, the other into the lateral. 

 In each opjning is set an iron irate of ample width and 

 night, and having a sliding door which may be opened 

 side wise to any given width and fastened at that point. 



