r portion goes up to the surface carrying solutions needed
by the plants. A portion goes into the plants to nourish them, and still
another part runs off the surface, carrying away the worn-out parts of
the soil.

Crops can use to advantage all the rain that falls during the growing
season; and in most cases crops are all the better for all the water
that can be carried over from the winter. There are many local
exceptions, but in general crops are best when the soil can be made to
absorb as much of the rainfall and snowfall as possible. This also
causes the least possible amount of wash from the land.

Doctor N. J. McGee says: "Scarcely anywhere in the United States is the
rainfall excessive, that is, greater than is needed by growing plants,
living animals and men. Nearly everywhere it falls below this standard.
In the western part the average rainfall is only about eighteen inches;
in the extreme eastern part the fall averages forty-eight inches. In the
western part much of the land is unable to produce crops at all except
when artificially watered. The eastern part might produce more abundant
crops, develop greater industries and support a larger population with a
rainfall of sixty inches than it is able to do with a rainfall of
forty-eight inches." As may readily be seen, the fly-off can be
controlled only in a very small degree, by conserving the moisture that
is in the soil, and so preventing it from evaporating too rapidly.

The cut-off can be controlled to a considerable extent through forestry
and scientific farming and it is very important that the supply should
be as carefully conserved as possible.

But it is in the run-off that the great waste of water occurs, and also
that great saving is possible. It has been found by careful estimate
that from eighty-five per cent. to ninety-five per cent. of the water
that flows to the sea is wasted in freshets or destructive floods.

We are not accustomed to think of the water as wasted, since it seems
beyond our control, but as we are taking a careful account of stock, and
seeing how our forests, our fuels and our minerals are disappearing, and
our soil being carried out to sea by the rushing waters, it is well to
consider, also, whether this great resource may not be so used as to
benefit mankind in many ways and at the same time lessen the drain on
other resources.

The water of streams may be divided as to use into four great classes.
The most important is t