THE IRRFGATION OF THE CANE. 



bottom, and 4 feet deep cost 83,000 ; this ditch is a private undertaking 

 and sells water to a number of plantations, the price charged being $2500 per 

 year per 1,000,000 gallons per day. 



Stubbs 14 quotes the cost of irrigation at Ewa as being $73*75 per acre per 

 year ; of which $36'62 were for pumping and $37'13 were for labour. Another 

 estimate gives the cost of pumping with coal at $8*10 per ton, and expressed 

 per 1,000,000 gallons lifted one foot as 



$ 

 Operating expenses .. .. .. .. -081 



Interest 6 per cent *014 



Depreciation . . *007 



102 



"With oil fuel the total expenses are reduced to $'074 for the same quantity. 

 This cost of irrigation may appear prohibitive until it is remembered that 

 in the Hawaiian Islands the average return per acre on unirrigated plantations 

 is, year in year out, about three tons of sugar per acre, and on the irrigated 

 plantations about six tons, so that three tons of sugar, less cost of cutting, 

 hauling and manufacture, are to be credited against $7 3 '75 as the cost of 

 irrigation. 



Some recent information regarding cost of irrigation in Porto Rico 15 gives 

 not dissimilar figures ; it is stated that here $25 per acre is the lowest figure 

 for pumping expenses, and that it often reaches $50. An estimate of the 

 Patillas and Carite schemes in this island, designed to irrigate 13,000 acres, 

 gives the total cost as $1,215,000, or nearly $100 per acre. 



REFERENCES IN CHAPTER VII. 



1. U. S. D. A. Office of Exp. Stations, Bull. 90. 



2. Trans. Am. Soc. Civ. Eng. 54, 129. 



3. Les irrigations. 



4. /. S. J., 50. 



5. W. I. B., 9, 1-36. 



6. Bull. Assoc., 19, 1412. 



7. Trans. Am. Soc. Civ. Eng., 54, 40. 



8. Proceedings I^tli Congress of the United Syndicate of Java Sugar Manufac- 



turers (1900). 



9. Soils, p. 234. 



10. Soils, p. 248. 



11. H. S. P. A. Agric. Bull 8. 



12. H. S. P. A. Agric. Bull. 11. 



13. H. S. P. A. Agric. Bull. 9. 



14. U. S. D. A. Office of Exp. Stations, Bull. 95. 



15. Wiilet & Gray's Weekly Report, 11, 11, 09. 



101 



