92 
SECOND BOOK. 
ground which is to be planted with cocoa, orange, 
coffee, and other young trees. 
10. Then we have heavy tools that are drawn by 
horses, cattle, or mules. Of these, the cultivator has 
large curved teeth, which stir the ground without 
turning it over as the plough does, and drag out the 
roots of weeds. The harrow acts like a large rake. 
Harrow. 
11. Sometimes it is needful for the soil to be 
pressed. For this purpose we have the roller, which 
presses in the seed, and makes the top-soil firm and 
fine enough for the tender roots of small plants. 
DRAINAGE. 
1. When we dig a hole in the ground, we find 
that at some distance down the soil is not like that 
at the top. It is neither so loose nor of so dark a 
colour. 
2. The darkness of the top-soil is caused by decayed 
parts of plants, or humus, being in it. The under- 
