54 
BULLETIN 462, U. S. DEPARTMENT OF AGRICULTURE. 
portable 4-inch pipe were attached to each outlet of the valve by a 
flexible clamp connection. The pipe was constructed of 26-gauge 
galvanized iron, made in lengths of 20 feet. Adjustable gates for 
letting out the water were placed in the portable pipe 3 feet apart, 
thus permitting any desired amount of water to be let into each fur- 
row. This was found to be a very great improvement on the type 
of gate first installed, as the sandy soil would not permit a good 
division of the water from a central point, since the furrows tended 
to flood together near the valve. This is prevented by the new 
arrangement. Both the valves and the small sliding gates in the 
V . j ■ ' ■' L f i 
Fig. 10. — Cross section of irrigation valve, showing method of connection to under- 
ground terra-cotta main : A, Main terra-cotta pipe ; B, 6-inch terra-cotta riser ; 
C, cast-iron valve ; D, connection hose ; E, portable pipe ; F, cemented joints ; 
G, ground surface. 
4-inch pipe have been improved, but the operating principle has been 
retained. 
Another system involving the use of terra-cotta pipe is in operation 
in the grove near Palatka. This system was designed by the writer 
and installed in the summer of 1914. The engineer who supervised 
the construction has submitted the following report on the system : 
The problem of efficient as well as economical irrigation, as applied to orange 
groves especially, has apparently been solved on the 50-acre grove at Palatka. 
Fla. On this project a flowing well of approximately 1.200 gallons per minute 
delivery furnishes the water supply, which is conveyed throughout the grove 
by 8-inch terra-cotta pipe. The pipe follows the contours of the highest eleva- 
tions, forming a complete circle around the grove and leading back to the 
starting point, a standpipe near the well. (PL VI, fig. 1.) Six-inch low-pressure 
irrigation valves of cast iron are placed at intervals of 100 feet along the main 
line, the water being conducted to the trees by means of a slip-joint galvanized- 
iron pipe. (PL VI, fig. 2. and fig. 10.) 
The plant is efficient, the water flows down the rows of trees guided some- 
what by furrows and banks, and the cost of operation is practically nothing 
