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PREFACE

TO THE REVISED EDITION.

J\HE marked progress which has been made in most of the departments of science embraced

in the study of Physical Geography since the issue of the original edition of “The
Elements of Physical Geography” has rendered the preparation of a revised edition a matter
of necessity.

The study of Physical Geography, including as it does not only the crust of the earth and

2 heated interior, but also the distribution of its land, water, air, plants, and animals, includes,
in its range, a great variety of topics, and necessitates for its proper elucidation many branches
of science. Some knowledge of the elementary principles of these sciences is necessary to the
proper study of Physical Geography. The number of such principles is great, and the temptation
naturally exists to encumber even an elementary text-book with such an abundance of leading
principles as to render it either incomprehensible, or too extended for actual use in the school-
room.

The author has endeavored in the revised edition to avoid undue multiplicity either of ele-
mentary principles or unimportant details. His object has been to develop forcibly the close inter-
dependence of the inanimate features of the earth’s surface, the land, water, and air, with its
animate features, its flora, and fauna, and to show the marked influence which all of these exert
on the development of the human race, and, therefore, on history itself.

Recognizing, from his standpoint of a teacher, the inadvisability of crowding a book with
new matter simply because it is new, the author has carefully avoided the introduction of new
theories unless they have been generally accepted by the best authorities. Old theories are in all
cases given the preference of new ones, unless the latter bear the stamp of general approval.
At the same time the results of recent investigations have been freely given in all cases where

they have been considered sufficiently authoritative.
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