RURAL ENGINEERING. 85 



eludes 38 complete tests and more than loo partial tests, the complete tests 

 showing efficiency and fuel consumption, and tbe partial tests the work done, 

 fuel consumption, cost of plant, and cost of operation. The power used included 

 i;asoline and steam engines and electric motors, and the types of pumps centrif- 

 ugal, rotary, deep-well, and air-lifts. The efficiencies given are the combined 

 efficiencies of engines, transmission, and pumps, being the ratio between the 

 indicated horsepower and the actual work done in lifting water. 



Complete tests were made of 9 plants with gasoline engines running centrif- 

 ugal pumps, and 2 ])lants with gasoline engines running deep-well pumps. 

 The efficiencies of the centrifugal-pump plants varied from 20 to 49 per cent, 

 the average being 34 per cent. With the deep- well pumps the efficiency was 33 

 per cent in one case and 52 per cent in the other, averaging 43 per cent. 



The electrically driven plants tested included 7 centrifugal pumps, 1 screw 

 pimip. 2 deep-well pumi)s, 1 triplex pump, and 1 rotary pump. The efficiencies of 

 the plants were as follows : Centrifugal, from 17 to 55 per cent, averaging 41 

 per cent : screw pump, 30 per cent ; deep-well, 37 and 41 per cent, averaging 

 39 per cent ; triplex 53 per cent, and rotary, two tests of same plant, 54 -and 49 

 per cent, averaging 51.5 per cent. ■' ■-■'■]i-- 



The steam-driven pumps included 7 centrifugal pumps. 2 plunger pumps, and 

 3 air lifts. All these plants used crude oil for fuel. The plant efficiencies 

 were as follows: Centrifugal, 34 to GO per cent, averaging 47 per cent; plunger, 

 93 and 91 per cent, averaging 92 per cent ; and air lifts 10 to 18 per cent, 

 aA'eraging 17 per cent. It should be remembered that these are tests of plants 

 in actual operation, and they probably represent very well what may be expected 

 from iilants of this type under field conditions. For the plants using centrifugal 

 pumps the plant efficiency does not seem to differ definitely from that for gaso- 

 line or electric plants. The plant efficiency of the plunger pumps was much 

 higher than for any other type, while for the air-lift plants it was very much 

 lower. 



The amount of crude oil consumed varied from over 0.8 gal. per indicated horse- 

 power hour for the smallest plant to a little over 0.2 gal. for the largest plant. 

 For those using centrifugal pumps the amount of crude oil used per useful 

 water horsepower hour varied from 2.5 gal. for the smallest plant to about 

 0.5 gal. for the most economical plants. A comparison with gasoline engines of 

 corresponding size showed that at least four times as much crude oil was required 

 when burned under a steam boiler as was needed of gasoline when used in an 

 internal-combustion engine. When steam plants run intermittently considerable 

 fuel is re(iuired in getting up steam preparatory to starting the plant, so it is 

 probable that in such cases the actual performance of the plants requires more 

 fuel in in-oportion to the work done than' is shown in the tests. 



A comparison of the results obtained with centrifugal pumps using gasoline, 

 electricity, and steam as motive power slujws that, at the prevailing prices, to 

 raise 1 acre-foot of water 1 ft. the cost of gasoline varies from li to 5 cts., of 

 electricity, from 4* to 10 cts., and of crude oil for generating steam from \h cts. 

 upward. The total cost, according to the rates used for fixed charges and the 

 figures obtained for attendance and maintenance, of raising 1 acre-foot of water 

 1 ft. for gasoline plants varies from 4 cts. upYJird. for electrical plants from 7 

 to 10 cts.. and for steam i)lants from 4 cts. upward. 



In addition to the comi)lete tests discussed above, fuel and water tests were 

 made on plants immediately about the city of Pomona. Cal. In each case the 

 nieasui'ements were made showing the work done or AAater horsepower and the 

 fuel consumed, the results being stated with gasoline in gallons per useful 

 water horsepower h<)nr, with electricity in kilowatts per useful water horse- 



