86 EXPERIMENT STATION RECORD. 



power hour, and with steam phiiits using crude oil in gallons per useful water 

 horsepower hour. 



Forty-seven plants having gasoline engines running centrifugal pumps varying 

 in size from 1^ in. to (5 in. showed consumptions rjLuming from 0.228 gal. to 2.414 

 gal. per useful water horsepower hour, the largest consumption being with the 

 smallest pump, and being more than ten times as large as the smallest consump- 

 tion. The average consumption was 0.52 gal. per useful water horsepower hour. 

 This is approximately 0.7 gal. to raise 1 acre-foot of water 1 ft. 



There are reported 41 plants having gasoline engines and deep-well pumps. 

 The fuel used per useful water horse])ower hour varied from 0.185 gal. to 4.81 

 gal., the average being 0.5(i3 gal. This ecjuals approximately 0.77 gal. per acre- 

 foot raised 1 ft. This is slightly higher than the consumption with centrifugal 

 pumps. 



Thirty electrically driven plants were tested. 17 having centrifugal pumps and 

 13 having deep-well pumps. The power used per useful water horsepower with 

 centrifugal pumps ranged from l.-Sf] to 3.10 kilowatts, averaging 2.12 kilowatts; 

 with deep-well pumps it ranged from 1.11 to 2.05 kilowatts, averaging 1.5 kilo- 

 watts. The advantage in this case is with the deep-well pumps, while with the 

 gasoline engines there was a slight advantage with the centrifugal pumps. 



Eleven steam-driven plants were tested, 3 having centrifugal pumps and 8 

 having air lifts, the average consumption of oil jier useful water horsepower 

 hour with the centrifugal pumps being 1.74 gal. and with the air lifts 1.59 gal,, 

 the advantage being with the air lifts. 



The most striking point shown bv the tables is the extreme variation in fuel 

 consumption between the most economical and the most wasteful plants of the 

 same type. As already noted, the highest consumption in the gasoline plants 

 was luore than ten times the lowest while the average was but little more than 

 one-fifth of the highest consumption and slightly more than twice the lowest, 

 indicating that proper adjustment and care might on the average i-educe the fuel 

 consumed by one-half. 



The report gives also a large amount of data regarding the cost of pumping 

 plants and the cost of attendance and rei)airs. and other interesting facts regard- 

 ing pumping water for irrigation. 



Mechanical tests of pumps and pumping plants used for irrigation and 

 drainage in Louisiana in 1905 and 1906, W. B. Gregory (I . S. Dcpt. A(/r., 

 Office Expt. Stas. Bid. 183. />/>. 12. fiy-s. .',). — The Louisiana tests, like the Cali- 

 fornia tests reported above, show the efficiency of the engines, transmissions, 

 and pumps, and the fuel consumption. "With 2 exceptions, the plants tested 

 had steam engines and used crude oil for fuel. Twelve plants had centrifugal 

 pumps and 3 had rotary pumps. The most, significant point in the results is 

 the high efficiency of the rotary pumps, one showing 81.7 per cent efficiency, 

 and another 83.3 per cent ; the third, however, showed only 30.1 per cent effi- 

 ciency. The efficiencies of the centrifugal-pump plants ranged from 5 to 68 

 per cent. The pump showing only 5 per cent efficiency was so badly adjusted 

 that the runner wore a hole through the casing and is not included in the 

 average which follows. The next lowest efficiency was 20.8 per cent, the avei*- 

 age for 11 plants being 47 per cent. This is exactly the efficiency found for 

 steam-driven centrifugal pumps in the California tests, the fuel being crude 

 oil in l)oth cases. 



In this report fuel consumption is given in pounds. If these are reduced to 

 gallons the oil used per useful water horsepower hour with centrifugal pumps 

 ranges from 0.29 gal. to 3.G0 gal., averaging 1.1 gal. The 3 rotary pumps 

 showed a consun)j)tion of 0.35 gal.. 0.27 gal., and 2.55 gal., the average being 

 1.00 gal., and the 2 lowest consumptions averaging 0.31 gal. Among all the 



