THE
POPULAR SCIENCE
MONTHLY
JUNE, 1910
| SCIENTIFIC WORK OF THE DEPARTMENT OF AGRICULTURE |
By W J McGEE, LL.D.
NATIONAL CONSERVATION COMMISSIONER (SECRETARY SECTION OF WATERS)
THE ancients saw in the four elements of earth, air, water and fire the basis of being; moderns recognize earth, air, water and sun as the prime requisites for individual and national existence.
The earth is of three parts: the life and growth on the surface; the surface, which sustains life and growth; and the part beneath, which sustains the surface with its life and growth.
The air is of four aspects: it is an extension of the earth; it yields a part of the substance for life and growth on the surface; it is a vehicle for movement of other things; and in its own movement it affects the surface and influences life and growth.
The water is of three forms, liquid, solid and gaseous, and performs five functions: it is a part of the earth; it is jointly with the air an extension of the earth; it yields the chief part of the substance for life and growth; it forms a vehicle for bodies and powers; and in its proper movement it is an effective agency of process, including life and growth.
The sun possesses several powers: it holds the earth in its place; it fixes the succession of days and seasons; it controls the forms of water and the movements of both water and air; it effectuates process, including life and growth; it yields heat, light and actinity; and it stores power on and beneath the surface in fuel to be released through fire.
The power and prosperity of men and nations are measured by knowledge of and control over these natural elements—i.e., human life is, as it were, balanced against and paired with the elementary ma-
