TWENTY-FOURTH ANNUAL FRUIT-GROWERS' CONVENTION. 



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that they break and become leaky, necessitating constant repairs. And 

 they also become filled with roots. Experiments with cement pipes 

 were begun in California about twenty-five years ago, and have con- 

 tinued to the present time, and yet the writer does not know of a single 

 orchard, nor can he get any trace of one, that is being irrigated now by 

 such a system that has been in existence five years. 



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

 on two and one half 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 



Sub-Irrigation. 



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; allowing 

 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 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 without any corresponding good to be gained thereby. 

 Elaborate tests in actual practice have shown that the water will seep 



