wash
away, the aim should be to keep the detritus open to such a depth that
it may take in as much as possible of the rainfall, yielding the water
to the streams through the springs. This end can generally be
accomplished by deep ploughing; it can, in almost all cases, be
attained by under-drainage. The effect of allowing the water to
penetrate is not only to diminish the superficial wearing, but to
maintain the process of subsoil and bed-rock decay by which the
detrital covering is naturally renewed. Where, as in many parts of the
country, the washing away of the soil can not otherwise be arrested,
the progress of the destruction can be delayed by forming with the
skilful use of the plough ditches of slight declivity leading along
the hillsides to the natural waterways. One of the most satisfactory
marks of the improvement which is now taking place in the agriculture
of the cotton-yielding States of this country is to be found in the
rapid increase in the use of the ditch system here mentioned. This
system, combined with ploughing in the manner where the earth is with
each overturning thrown uphill, will greatly reduce the destructive
effect of rainfall on steep-lying fields. But the only effective
protection, however, is accomplished by carefully terracing the
slopes, so that the tilled ground lies in level benches. This system
is extensively followed in the thickly settled portions of Europe, but
it may be a century before it will be much used in this country.

The duty of the soil-tiller by the earth with which he deals may be
briefly summed up: He should look upon himself as an agent necessarily
interfering with the operations which naturally form and preserve the
soil. He should see that his work brings two risks; he may impoverish
the accumulation of detrital material by taking out the plant food
more rapidly than it is prepared for use. This injurious result may be
at any time reparable by a proper use of manures. Not so, however,
with the other form of destruction, which results in the actual
removal of the soil materials. Where neglect has brought about this
disaster, it can only be repaired by leaving the area to recover
beneath the slowly formed forest coating. This process in almost all
cases requires many thousands of years for its accomplishment. The man
who has wrought such destruction has harmed the inheritance of life.

CHAPTER IX.

THE ROCKS AN