Robert Trous Paine to Harvard College

THE

AGE OF THE EARTH

CONSIDERED

GEOLOGICALLY AND HISTORICALLY.

BY WILLIAM RHIND,

MEMBER OF THE ROYAL COLLEGE OF SURGEONS, MEMBER OF THE ROYAL MEDICAL SOCIETY
OF EDINBURGH, AUTHOR OF " ELEMENTS OF GEOLOGY," AND "GEOLOGY OF THE

ENVIRONS OF EDINBURGH," &c.

Sit numine vestra

Pandere res alta terra et caligine mersas.

VIRG. En.

EDINBURGH :

FRASER & CO. 54, NORTH BRIDGE;
SMITH, ELDER, & CO. AND H. WASHBOURNE, LONDON.
W. CURRY, JUN. & CO. DUBLIN.

PREFACE.

THE following analysis of the prevailing geological opinions of the day would not have. been attempted, had it not been thought that the question cannot long rest where it now stands. Neither would the author have set himself against an array of high authorities on the science, had he not been equally aware of the conflicting and unstable nature of opinion, even among those authorities, on the subject at issue. To any one who has watched the progress of theoretical geology for the last few years,-without even reverting to the speculations of the last century, where opinion has so often vacillated and changed on the subject, and where so many hasty conclusions have been formed, that scarcely has an author his speculations half through the press, when the last part must