IRRIGATION 
79 
land have been brought under cultivation and utilized in 
growing lettuce, celery and other crops. The tile serve 
both for irrigation and for drainage. An impervious bed 
of hardpan lies from 2 to 4 feet below the surface and the 
sandy or loamy top soil is about 18 inches deep. The 4- 
inch water mains are made of sewer tile, cemented at the 
joints, the 3-inch laterals of drain tile are 20 to 25 feet apart 
and 12 to 15 inches below the surface. Sawdust, cinders 
FIG. 15. SEVEN-OUTLET NOZZLE AND 3 -OUTLET NOZZLE, 
MANAWAY SYSTEM OF IRRIGATION 
or moss are placed over the joints to prevent filling with 
sand. A fall of at least I inch in ioo feet of tile is pro- 
vided for drainage. The laterals run into open ditches 
dug for drainage purposes. Subirrigation is an ideal 
system for conditions as they exist at Sanford 
122. The overhead system of irrigation has entirely 
revolutionized garden irrigation in the East. Numerous 
