PREFACE. 



vii 



tematic treatise. In this part of the volume a 

 method of classifying the subjects of geological re- 

 search has been adopted, in accordance with the 

 elementary views given in the first part, so as to 

 present a large mass of arranged information in a 

 small compass. The advantages attending this 

 systematic plan are too obvious to need remark. 



The reader will perceive that I have extensively 

 consulted the able works of Bakewell, Philips, Ly- 

 ell, De la Beche, Ure, Conybeare, Buckland, Man- 

 tell, Cuvier, &c, of Europe ; and the State Geolo- 

 gical Reports of Messrs. Hitchcock, Jackson, Beck, 

 Conrad, Featherstonhaugh, Emmons, Hall, Vanux- 

 em, Eights, Eaton, Wm. B. and H. D. Rogers, Du- 

 catel, Hildreth, Briggs, Troost, Mather, Perciva], 

 Shepherd, and Houghton ; whose labours are shed- 

 ding a flood of light upon the geological structure 

 and mineral treasures of this country. Besides 

 these, I have had free access to all the scientific pe- 

 riodical journals, and been favoured by Professors 

 Torrey and Francis of this city with numerous im- 

 portant documents, for which I desire to express my 

 grateful acknowledgments. I have also drawn 

 largely upon Mr. Maclure and Professor Silliman, 

 whose names, indeed, ought to stand first on the list 

 of American geologists ; for the able " Sketch of the 

 Geology of the United States" by the former, and the 

 "Journal of Science and the Arts" conducted by the 

 latter, have done, perhaps more to diffuse a taste for 

 geological studies among us than all other causes 

 united. It will be seen that, in some instances, I 

 have not hesitated to employ the language of others 

 in the description of facts, where it seemed appro- 

 priate ; but in the expression of opinions I have 



