Physical geography. By Mary Somerville ...

PHYSICAL GEOGRAPHY.
CHAPTER I.
GEOLOGY.
Of Physical Geography- Position of the Earth in the Solar System- Distance from the Sun-Civil Year-Inclination of Terrestrial Orbi —Mass
of the Sun - Distance of the Moon - Figure and Density of the Earth
from the Motions of the Moon — Figure of the Earth from Arcs of the
Meridian - from Oscillations of Pendulum - Local Disturbances - Mean
Density of the Earth - Known Depth below its Surface — Outline of
Geology.
PHYSICAL GEOGRAPHY is a description of the earth, the sea,
and the air, with their inhabitants animal and vegetable, of the
distribution of these organized beings, and the causes of that distribution. Political and arbitrary divisions are disregarded, the sea
and the land are considered only with respect to those great features
that have been stamped upon them by the hand of the Almighty,
and man himself is viewed but as a fellow-inhabitant of the globe
with other created things, yet influencing them to a certain extent
by his actions, and influenced in return. The effects of his intel-.
lectual superiority on the inferior animals, and even on his own condition, by the subjection of some of the most powerful agents in
nature to his will, together with the other causes which have had
the greatest influence on his physical and moral state, are among
the most important subjects of this science.
The former state of our terrestrial habitation, the successive con
vulsions which have ultimately led to its present geographical
arrangement, and to the actual distribution of land and water, so
powerfully influential on the destinies of mankind, are circumstances
of primary importance.
The position of the earth with regard to the sun, and its connexion
with the bodies of the solar system, have been noticed by the author
elsewhere. It was there shown that our globe forms but an atom in
the immensity of space, utterly invisible from the nearest fixed star,
and scarcely a telescopic object to the remote planets of our system.
The increase of temperature with the depth below the surface of the
earth, and the tremendous desolation hurled over wide regions by
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