34 BULLETIN 1067, U. S. DEPARTMENT OE AGRICULTURE. 
the discharge side is 2 feet. The suction and discharge pipes are each 
about 25 feet long, and the main shaft of the pump is about 3 feet 
above average water level in the discharge canal. 
METHOD OF CONDUCTING THE TEST. 
Two tests were run on this plant. In the first the discharge of the 
pumps was measured by Pitot tubes placed in the discharge pipes 
at a distance of about 10 feet from the pumps. This proved to be so 
close to the pump that eddy currents interfered with the proper 
working of the tubes. The results for the quantity of water pumped 
during the test were found to be too erratic to be of value. A week 
later the test was run again on one unit with the Pitot tubes placed 
in the suction pipes. The readings taken on the suction side were 
very consistent. The lift used in computing the water horsepower 
was obtained by reading gages set in the suction and discharge canals. 
The fuel oil used in the engines, a distillate oil of specific gravity 
0.875 at 72° F., was weighed in buckets by means of a spring balance. 
In the first test the indicated horsepower of the engine was measured 
by an indicator using a 250 spring. In the second an 80 spring was 
used with entire success. m From 10 to 20 complete cycles were taken 
on each card and the several areas were averaged. While the results 
of the first test of the pumps are of no value, the results of the test 
of the engine compare very well with the results of the second test 
and are considered of value. Table 25 is a summary of the first 
engine test. 
Table 25. 
Length of run, hours 
Revolutions per minute, average 
Average indicated horsepower 
Minimum indicated horsepower 
Revolutions per minute at minimum indicated horsepower 
Maximum indicated horsepower 
Revolutions per minute at maximum indicated horsepower 
Total pounds of fuel oil Nos. 1 and 2 
Pounds of fuel oil per indicated horsepower-hour 
Pounds per brake horsepower (assuming mechanical efficiency of 80 per cent). 
Unit 
Unit 
No. 1. 
No. 2. 
4 
4 
204 
211 
32.6 
41.6 
26.4 
28.4 
193 
183 
37.7 
50.6 
213 
221 
219.2 
.74 
.92 
During the second test on unit No. 1 the speed of the engine was 
somewhat less than in the previous test, and the engine seemed to be 
working much more smoothly. The results of the test are given in 
Table 26. 
