PEEPACE TO THE SECOND EDITION. 



THE motives which originally induced the author to prepare 

 this volume for the public were briefly these. During the 

 course of some experience as a lecturer on geology, he had 

 constantly been in the habit of recommending the various 

 works already published on the science, and had as constantly 

 been requested to name some treatise more particularly 

 intended for the tyro, and more expressly designed to convey 

 that preliminary information which the mere beginner is so 

 anxious to acquire. Not being aware of the existence of 

 such a production, and being naturally desirous to comply 

 with a demand so strongly and so extensively urged, he 

 undertook the present publication ; which, in addition to its 

 claims on the attention of the novice, its adaptation for the 

 use of schools, and of classes in literary and scientific insti- 

 tutions, would, it was hoped, be found not wholly devoid of 

 interest for those who had already attained some proficiency 

 in the science. 



The flattering approval of the public press, the favourable 

 manner in which the volume was received by the public, and 

 the sale of a large impression in a comparatively brief space, 

 have proved the correctness of these anticipations, and have 

 induced the author to publish the present edition ; which, 

 beside a large increase of letter-press, contains a new 

 frontispiece, with nearly one hundred new wood engravings, 



