
SPRAY IRRIGATION. Any 
have movable parts to assist in the distribution of water by cen- 
trifugal force or water power. 
The efficiencies of nozzles found in use were determined by a series 
of tests made under the direction of this office in 1909 and the re- 
sults are here summarized. 
A popular solid nozzle (No. 4, fig. 11) was found to have a capa- 
city of 1.93 cubic feet per minute (14.5 gallons per minute) under a 
pressure of 20 pounds per square inch, and it gave a fair lateral 
spread of 40 feet. Under 25 pounds pressure its capacity was 2.45 
cubic feet per minute (18.4 gallons per minute) with a fair lateral’ 
spread of 42 feet. The zone receiving the greatest amount of water 
per square foot was found to be an annular ring about 15 feet from: 
the nozzle. This ring received about 40 per cent more water per 

Fie. 11.—Types of circular-spray nozzles. 
square foot than did the surface at 5 feet or 18 feet from the nozzle. 
A popular adjustable nozzle (No. 5, fig. 11) was found to have a 
capacity of 0.98 cubic foot per minute (7.3 gallons per minute) 
under 20 pounds hydraulic pressure and a fair lateral spread of 35 
feet. Under 25 pounds its capacity was 1.23 cubic feet (9.2 gallons): 
per minute and it gave a fair lateral spread of 38 feet. The nozzle 
was opened one-half turn during the above test, which gives a 
medium spray. <A zone 12 feet from the nozzle received about 30 
per cent more water per square foot than did the surface at 3 feet or 
15 feet from the nozzle. 
A popular rotary nozzle (No. 2, fig. 11) was found to have a 
capacity of 0.43 cubic foot (3.2 gallons) per minute under hydraulic 
pressure of 20 pounds, and it gave a fair lateral spread of 32 feet. 
66687°—Bull. 495—17 3 




