^ PREPAKATION OF THE SOIL. 61 



CTilar which touches the surface beneath the other end. 

 Thus a d^ hg. 2, being the surface of the hill, 

 and the eight feet board with the level resting upon 

 it, e d, will be the rise in eight feet and e d, less the 

 slope given to the border will be the height of each 

 step or terrace. Having found this, the next step is 

 to cut a perpendicular face half the height of the pro- 

 posed terrace at the foot of the hill and against it to 

 build a wall as high as may be required. This is best 

 formed of dry stone, though the bank is sometimes 

 left with a good deal of slope, and sodded, the sods 

 being pinned to the face of the bank with stakes until 

 the roots have penetrated sufficiently to hold. The 

 sods for this purpose should not be cut square, but dia- 

 mond form, so that the face of the bank would pre- 

 sent the appearance shown in fig. 3. But sods are 



Fig. 8. 



objectionable from the fact that they not only keep 

 the air moist in the vicinity of^the vines, but also 

 abstract a good deal of nutriment from the soil, and 

 unless kept neatly mown present a very bad appear- 



