AN INQUIRY HOW FAR THE FORMER CHANGES OF THE
EARTH'S SURFACE ARE REFERABLE TO .
CAUSES NOW IN OPERATION.
CHARLES LYELL, ESQ., F.R.S.
PRESIDENT OF THE GEOLOGICAL SOCIETY OF LONDON.
“Amid all the revolutions of the globe, the economy of Nature has been uniform, and her laws
are the only things that have resisted the general movement. The rivers and the rocks, the seas and
the continents, have been changed in all their parts; but the laws which direct those changes, and
the rules to which they are subject, have remained invariably the same.”—Playfair, Illustrations of
JAMES KAY, JUN. & BROTHER, 122 CHESTNUT STREET.
PITTSBURGH : JOHN I. KAY & CO.