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; :' :::':'r~ ^r::, :: :::::::: :::'': :: ::::■---:■■:■:■■■:;::;;::■■;;;■::: v: , ',v , 'v , - j. ~ , t; : , :: . ——— , ": :" , ":' , ;;;' ■"< , 



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. (PI. 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. (PI. 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 



