26 STABILITY OF NATURE. 
tion, or of tall meadow-grass ; what given out again by surfaces 
so covered, or by bare ground of various textures and compo- 
sition, under different conditions of atmospheric temperature, 
pressure, and humidity; or what is the amount of evaporation 
from water, ice, or snow, under the varying exposures to which, 
in actual nature, they are constantly subjected. If, then, we 
are so ignorant of all these climatic phenomena in the best- 
known regions inhabited by man, it is evident that we can rely 
little upon theoretical deductions applied to the former more 
natural state of the same regions—less still to such as are adopt- 
ed with respect to distant, strange, and primitive countries. 
Stability of Nature. 
Nature, left undisturbed, so fashions her territory as to give 
it almost unchanging permanence of form, outline, and propor- 
tion, except when shattered by geologic convulsions; and in 
these comparatively rare cases of derangement, she sets herself 
at once to repair the superficial damage, and to restore, as nearly 
as practicable, the former aspect of her dominion. In new 
countries, the natural inclination of the ground, the self-formed 
slopes and levels, are generally such as best secure the stability 
of the soil. They have been graded and lowered or elevated 
by frost and chemical forces and gravitation and the flow of 
water and vegetable deposit and the action of the winds, until, 
by a general compensation of conflicting forces, a condition of 
equilibrium has been reached which, without the action of man, 
would remain, with little fluctuation, for countless ages. 
We need not go far back to reach a period when, in all that 
portion of the North American continent which has been occu- 
pied by British colonization, the geographical elements very 
nearly balanced and compensated each other. At the commence- 
ment of the seventeenth century, the soil, with insignificant ex- 
ceptions, was covered with forests ; * and whenever the Indian, 
*T do not here speak of the vast prairie region of the Mississippi valley, 
which cannot properly be said ever to have been a field of British colonization; 
