trained Forester must know the forest as a doctor knows the human
machine. First of all, he must be able to distinguish the different
trees of which the forest is composed, for that is like learning to
read. He must know the way they are made and the way they grow; but far
more important than all else, he must base his knowledge upon that part
of forestry which is called Silvics, the knowledge of the relation of
trees to light, heat, and moisture, to the soil, and to each other.

The well-trained Forester must also know the forest shrubs and at least
the more important smaller forest plants, something of the insect and
animal life of his domain, and the birds and fish. He must have a good
working knowledge of rocks, soils, and streams, and of the methods of
making roads, trails, and bridges. He should be an expert in woodcraft,
able to travel the forest safely and surely by day or by night. It is
essential that he should have a knowledge of the theory and the practice
of lumbering, and he should know something about lumber markets and the
value of lumber, about surveying and map making, and many other matters
which are considered more at length in the Chapter on Training. There
are as yet in America comparatively few men who have acquired even
fairly well the more important knowledge which should be included in the
training of a Forester.

THE FOREST AND THE NATION

The position of the forest in the housekeeping of any nation is unlike
that of any other great natural resource, for the forest not only
furnishes wood, without which civilization as we know it would be
impossible, but serves also to protect or make valuable many of the
other things without which we could not get on. Thus the forest cover
protects the soil from the effects of wind, and holds it in place. For
lack of it hundreds of thousands of square miles have been converted by
the winds from moderately fertile, productive land to arid drifting
sands. Narrow strips of forest planted as windbreaks make agriculture
possible in certain regions by preventing destruction of crops by
moisture-stealing dry winds which so afflict the central portions of our
country.

Without the forests the great bulk of our mining for coal, metals, and
the precious minerals would be either impossible or vastly more
expensive than it is at present, because the galleries of mines are
propped with wood, and so protected against caving in. So far, no
satisfactory substitu