PKEFACE TO THE FIEST EDITION. 



1^" preparing the following work I have not attempted to make an 

 exhaustive manual to be thumbed by the special student ; for, even if 

 I felt able to write such a work, Prof. Dana's is already in the field, 

 and is all that can be desired in this respect. I have endeavored only 

 to present clearly to the thoroughly cultured and intelligent student 

 and reader whatever is best and most interesting in Geological Science. 

 I have attempted to realize what I conceive to be comprised in the 

 word elements^ as contradistinguished from manual. I have attempted 

 to give a really scientific presentation of all the departments of the 

 wide field of geology, at the same time avoiding too great multiplica- 

 tion of detail. I have desired to make a work which shall be both 

 interesting and profitable to the intelligent general reader, and at the 

 same time a suitable text-book for the higher classes of our colleges. 

 In the selection of material and mode of presentation I have been 

 guided by long experience, as to what it is possible to make interesting 

 to a class of young men, somewhat advanced in general culture and 

 eager for knowledge, but not expecting to become special geologists. 

 In a word, I have tried to give such knowledge as every thoroughly 

 cultured man ought to have, and at the same time is a suitable founda- 

 tion for the further prosecution of the subject to those who so desire. 

 The vvork is the substance of a course of lectures to a senior class, 

 organized, compacted, and disencumbered of too much detail, by re- 

 presentation for many successive years, and now for the first time 

 reduced to writing. 



Most text-books now in use in this country are, in my opinion, 

 either too elementary on the one hand, or else adapted as manuals for 

 the specialists on the other. I wish to fill this gap — to supply a want 

 felt by many intelligent students and general readers, who desire a 



