iv 



PREFACP. 



tive nucleus, presents more advantages. But according to 

 De Luc, America alone must give a system of general stra-^ 

 ta. How far I have succeeded in my attempt to present 

 such a system, future investigations (not the opinions and 

 closet speculations of the geologists of either continent) 

 must decide. For the system adopted in this text-book, I 

 rely on my own personal examinations, aided by Dr. T. R. 

 and Prof. L. C. Beck, M. H. Webster, and J. Eights, 

 more or less supported by Professors Hitchcock, Dewey, 

 and Emmons, from the Atlantic to the western extremity of 

 Lake Erie. For the remainder, I rely upon the personal 

 examinations and collected specimens, which I have now 

 before me, of Dr. Zina Pitcher and Dr. Edwin James. 

 Messrs. Schoolcraft and Peter have also contributed much. 

 We have, altogether, traversed a succession of northerly 

 and southerly strata through more than forty degrees of 

 longitude. 



A texP'hooh is too small a name for these days of puffing 

 arrogance. But I propose to present all my supposed here- 

 sies to the geological fraternity in this form and under this 

 title. And I beg the favor of the most rigorous criticism up- 

 on this book, small as it is. To stimulate men of science 

 to the work of examination and of criticism, I will state ; 

 that I intend to publish considerable in scientific journals, 

 also a full system, upon this plan. As 1 have had more 

 than seven thousand pupils already, *and shall probably have 

 more still, it will be well for them *' to be on the alert" if 

 I am propagating errors. I am not in sport — I have, dur- 

 ing the last fifteen years, travelled over seventeen thousand 

 miles, for the express purpose of collecting geological ma- 

 terials ; the results of which are comprised in this little oc- 

 tavo pamphlet, and exhibited in the accompanying map and 

 wood cuts. , 



» Rather, auditors. ^ "^^ 



