28 



the drum. Fig. 23 shows a simple form of register of this class used in 

 southern California, the cost of which is about $40. 



The other class of register differs from the first class in that the cylinder 

 is placed horizontally and is rotated by the float instead of by the clock and 

 the pencil is carried parallel with the cylinder by connections with the 

 clock. In each case the record obtained is the result of two motions which 

 give an irregular line showing the fluctuations and giving the depth of 

 water at any time. The various types of registers are illustrated and de- 

 scribed in Bulletin 86, part 1, of the Office of Experiment Stations of the 

 U. S. Department of Agriculture, Washington, D. C. 



The cost of registers ranges from about $40 upwards and for that reason 

 they are seldom used for the measurement of water delivered to irrigators. 

 They are, however, of much value in the operation of a system when in- 

 stalled at the head of laterals. 



Fig. 23. Automatic register used at Riverside, California. 



(O. E. S. Bulletin 86, Part I., U. S. Dept. Agr.) 



