Geologies; and, that the THIRD PART considers the MODE of the CHANGES or REVOLUTIONS which the Earth has undergone, according to both Geologies.

The results of these several investigations, will be found combined in the Conclusion, with which the treatise is terminated.

I have endeavoured, by keeping the thread of the argument simple and compressed, to avoid all superfluous dilatation and digression; in which endeavour, I hope I shall be found to have succeeded. It was originally designed, and it has been solely prepared, for such earnest and sincere inquirers as are anxious to relieve their minds from perplexity, or to disengage them from error, in the high and important subjects of which it treats; and who are willing to advance in the prosecution of the truth respecting them, as far as the principles of that truth, actively pursued, are capable of conducting them. Such advance is entirely frustrated by the practice which, in similar discussions, has too frequently prevailed, of

maintaining a constant skirmish with cavillers and sophists; whose policy it is, to challenge a perpetual warfare on the road, in order that it may not be travelled to the END. By yielding ourselves to that stratagem, we contribute in effect to promote one great end of infidelity. Whereas, if we will only resolutely set forward, and pursue our progress uninterruptedly under the safeguard of a sound and powerful principle, we may set all adversaries at defiance; and, by pressing on to the utmost extent to which that principle will lead us, we shall at length arrive at the term from which it was the design of the adversary to preclude us. It is a weak system of tactics, which, in an enterprise of great moment, would stop to engage with every hovering band that attempts to harass the march; whilst, at the same time, there exists a consciousness of force sufficient to accomplish the enterprise in spite of all opposition.

To those among the opponents who cherish a general regard for truth, and many such

there are, the manifestation of the Sacred Truth which we shall have gained in their despite, will operate with advantage; and they themselves will thus become benefited, by the resolution with which their arms shall have been slighted and their opposition disregarded. With respect to all other opponents; as we cannot entertain an hope of serving them by our success, so neither shall we suffer ourselves to be interrupted by their opposition: –obturatá aure transibimus.

INTRODUCTION

ΤΟ

THE PRESENT EDITION.

SHORTLY after the publication of the first Edition of the Comparative Estimate, several very important works on Geology appeared in quick succession before the world; viz.

The first Volume of the Geology of England and Wales, with the Introduction of the Rev. W. D. CONY

BEARE.

Mr. Professor BUCKLAND's Reliquia Diluviana. M. CUVIER's Ossemens Fossiles. New Edition. The Translation of M. HUMBOLDT'S Geognostical Essay on the Superposition of Rocks in both Hemispheres. The Edinburgh and Quarterly Reviews of the Reliquia Diluviana.

To these may be added, the Geological Disquisition introduced by the Rev. G. S. FABER into his Treatise on the Three Dispensations.

Also, the reviews of this present Work, in the Eclectic Review, in the Journal of Science, and lastly, in the British Critic.

The important matters which the former of those works contained, could not therefore have been noticed in the first edition of this treatise; and consequently, in