chap. I.] STIRRING THE SOIL. 
21 
plants. This is very necessary, as the earth 
is a bad conductor of heat; and where the 
surface of the soil is become so hard as to 
exclude the air from the roots of the plants, 
the ground in which they grow will be nearly 
as cold in summer as in winter. Besides, 
when the surface of the ground is hard, the 
rain instead of soaking gradually into it, runs 
off, or evaporates, without being of any service 
to the roots. The operation of forking con¬ 
sists merely in thrusting the fork a little way 
into the ground by the application of the foot 
to the hilt, and then raising the ground by 
pulling back the handle as in digging, so as 
to loosen the earth without raising it. The 
ground may thus be roughly pulverized to a 
considerable depth, without dividing the 
roots of the plants; which would have been 
inevitable if the operator had used a spade. 
Hoeing .—There are several different kinds 
of hoes which are used for getting up weeds, 
for loosening the soil, for drawing it up round 
the stems of growing plants, and for making 
a shallow furrow or drill for sowing seeds. 
The different kinds all belong to two great 
divisions: viz. the draw hoe and the thrust 
