DRAINAGE OF IRRIGATED LAND. 
29 
leather belting around a cylindrical wooden rod, first having driven 
the belting full of nails of such length thai the outside diameter of the 
completed brush is somewhat smaller than the inside diameter of the 
tile to be cleaned. These devices may be operated most conveniently 
by means of jointed sewer rods. The hit t er are made up in 3 or 4 foot 
sections which are fitted with couplings so arranged that they may 
be joined when two sections are placed at right angles, and are locked 
together when the two sections are in line. Working in a manhole I 
feet square, a man can easily put together and operate several hun- 
dred feet of rod in a tile line. Figure 22 shows a set of sewer rods and 
cleaning devices that have given satisfaction in operation. 
SUBSEQUENT TREATMENT OF LAND. 
While drainage is essential to the reclamation of water-logged and 
alkali lands, subsequent work is necessary for the complete redemp- 
^*W-?> 
Fig. 22.— Sewer rods and tile-cleaning devices. 
tion of the soil. The alkali salts which may have accumulated in the 
upper portions of the soil must be removed and the proper physical 
condition of the soil itself must be restored. Humus must be increased 
and it will be necessary that steps be taken to reduce evaporation, to 
maintain a downward movement of the salt solution, and to prevent 
any future rise of the latter. 
The salts, being soluble, will usually be removed in time by the 
action of ordinary precipitation, and this latter is always an important 
factor in the subsequent treatment; however, the natural method is 
often too slow and is sometimes entirely ineffective, due to the fact 
that the precipitation is sufficient to saturate only a foot or so of the 
soil, and the excessive evaporation immediately returns the salts to 
the surface. 
If expedition be desired, a good-sized stream of irrigation water 
should be turned on the land and allowed to percolate through the 
soil as rapidly as possible. This is best accomplished by diking the 
