s, and in the filing and care of
papers generally, and for the supply of stationery, tools, and
instruments, and the renting of quarters,--in a word, for the whole of
the more or less routine transaction of business which is essential to
keep so large an organization at the highest point of efficiency.

[Illustration: BRUSH PILING IN A NATIONAL FOREST TIMBER SALE]

The office work needed in the mapping of the National Forests, with
all their resources, boundaries, and interior holdings, is in charge of
the Branch of Operation. So is the immense amount of drafting which is
necessary in the other work of the Service, and the photographic
laboratory in which maps are reproduced and where permanent photographic
records of the condition of the forest are made.

The third branch, that of Silviculture, is the most important of all. It
has oversight of the practice of forestry on all the National Forests,
and of all scientific forest studies in the National Forests and
outside. It is here that the conditions in the contracts under which the
larger timber sales are made are finally examined and approved, and here
are found the inspectors whose duty it is not only to see that the work
is well done, but to labor constantly for improvements in methods as
well as in results. Here centres the preparation of forest working
plans, and the knowledge of lumber and the lumber markets.

The Branch of Silviculture has charge also of National cooperation for
the advancement of forestry with the several States, and in particular
for fire protection under the Weeks law. This form of cooperation has
made the knowledge and equipment of the Forest Service available for the
study of State forest resources and forest problems, and much of the
progress in forestry made by the States is directly due to it.

Under the Branch of Silviculture, the Office of Forest Investigations
brings together all that is known of the nature and growth of trees in
this country, and to some extent in other countries also, conducts
independent studies of the greatest value in developing better methods
of securing the reproduction of important forest trees, and computes
the enormous number of forest measurements dealing with the stand and
the rate of growth of trees and forests that are turned in by the
parties engaged in forest investigation in the field. Under the Office
of Forest Investigations, studies in forest distribution and in the
structure of wood are carrie