CHAPTER XXV. 



195 



any trace of one, that is being irrigated now by such a system that 

 has been in existence five years. 



Mr. Jas. Campbell, of Pasadena, tried a system of sub-irrigation in 

 two and one-hali acres of orange orchard some twelve or fifteen years 

 ago, with three-inch continuous cement pipes laid twenty inches deep. 

 He says the system worked with perfect satisfaction for three or four 

 years, which was as long as the pipe kept in good order. He does 

 not think that he used one-third the amount of water that he did by 

 surface irrigation. Indeed, he could not have used as much as one- 

 third, for he states that the reservoir from which he irrigated his 

 two and one-half acres contained but 10,000 gallons of water, which 

 would only be at the rate of 4,000 gallons per acre per irrigation; al- 

 lowing two irrigations per month, it would only be 8,000 gallons per 

 acre, or equivalent to one miner's inch continuous flow to about 48 



Sob-Irrigation 

 acres. He also says that the labor for cultivation was much less than 

 in orchards irrigated by the surface method. 



There are several patented systems, which require the underground 

 discharge to be surrounded with coarse stones or gravel, or both, and 

 even with cement flagging under the outlet; but all these only increase 

 labor and expense to a system without any corresponding good to be 



