IN THE EVERGLADES 35 



accomplished by what is locally known as the overhead system. 

 It is a very successful method, as it not only is economical of 

 water, but it would be impossible to hold water in sandy subsoil on 

 account of its leachy character. This style is the most costly to 

 install. Besides the expense of mains, consisting of 2 to 4 inch 

 pipe, laterals must be laid 25 to 40 feet apart, with long or short 

 stand pipes (usually about 6 feet high) of %-inch iron pipe 

 placed a corresponding distance apart. 



These stand pipes are crowned with various kinds of spray 

 nozzles, aiming chiefly to get such a nozzle as will distribute over 

 as large an area as possible. This system has its advantages as 

 well as its disadvantages. Among the former may be counted 

 the prevention of damaging frost; it also washes off red spider 

 and makes it unpleasant for leaf-eating insects ; on the other hand, 

 it has a tendency to produce a class of fungi such as flourish best 

 where the foliage is damp. 



This overhead system requires a pressure of about 25 pounds 

 per square inch to properly force the water and to generate such a 

 spray as will best imitate a fine rain. Spraying is best applied 

 evenings or during the night, but beneficial applications can be 

 made during cloudy weather. In all attempts at irrigation, you 

 will make no mistake by using a surplus of water and by keeping 

 the soil especially if of a sandy nature constantly in a moist 

 condition; and unless this is done religiously, absolute failure is 

 liable to result. 



Probably the method that is most successful is the one of 

 placing under-ground tiles and forcing water through them. 

 This is the system so largely used at Sanford, Florida. However, 

 this system is only feasible where there is a substratum of soil 

 which is more or less impervious to water, such as clay, marl or 

 hard-pan subsoil. 



When the Everglade drainage is completed it is proposed to 

 install locks in the canals and thereby control the water level in 

 the soil. This will at all times provide ample moisture and will 

 eventually assure very cheap irrigation for this entire area. But 

 until this work is completed, which will take some time to accom- 



