36 BULLETIN 512, U. S. DEPARTMENT OF AGRICULTURE. 
15 to 20 feet in width. Then, commencing at the center again, the 
strip is plowed in the same manner as before. This procedure is 
repeated until the terrace has reached the desired height. Many 
farmers allow the loose earth to be settled by a rain between plowings 
so that the dirt will turn better. However, it is safer to build the 
terrace to the desired height at the start for, if a heavy rain, sufficient 
to overtop the terrace, comes between plowings, much of the original 
work is undone and considerable damage occurs from erosion. <A: 
disk plow can be used successfully to throw up loose dirt, and the 
ordinary road grader is employed often and is adapted especially 
to such work. : 
The most commonly used and cheapest implement for throwing 
up a terrace is a wooden, V-shaped drag. Plate VI, figure 2, and 
Plate VII, figure 1, show two terrace drags that have been used 
satisfactorily. Figure 17 shows a terrace drag with dimensions. 
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Fic. 17.—A terrace drag. 
After the first three or four furrows have been plowed on each side 
of the center line of the terrace, the drag is used to push the loose 
earth toward the center and thus build the terrace higher. The 
plowing is resumed and the drag used again, and this is done 
repeatedly until the terrace has attained the desired width. If the | 
terrace is not built sufficiently high the first time, the work is started 
again at the center and the plowing and dragging are repeated. The 
longer side of the drag is hinged so that for the first few furrows 
the hinged portion is allowed to swing loose. As the terrace increases 
in width, and it is desired to move the loose earth a greater dis- 
tance, the removable brace is set in position and the hinged portion 
is brought into use. The short side of the drag is made to follow the 
open furrow; this holds the drag in the proper position. The piece 
to which the hitch is made should be set at a vertical angle with 
the shorter side, as shown in figure 17, and also at a horizontal 
angle, as shown in Plate VII, figure 1. The former tends to keep 
the short side parallel with the bottom of the furrow and the latter 
