INTRODUCTION. 81 



elusions, I have chosen in this place to go through with the preliminary- 

 description of the several formations, their character and geographical 

 distribution, in order that the student may have before him an example 

 upon which! would found my general propositions. I do this also since 

 it has been from the actual study of this series of strata in their accu- 

 mulation and distribution, that I have arrived at the results here 

 given. These conclusions, moreover, have been deduced by studying the 

 rocks, and the phenomena attending them, entirely independent of the 

 theoretical views advanced by other authors. I have necessarily in- 

 corporated the general philosophic views so long ago clearly set forth 

 by Babbage, Herschel, Lyell and others ; since these had early been 

 fixed in my mind as a part of the elements and principles of geological 

 science. In this preliminary paper I have not thought it necessary to 

 enter into any special discussion of the structure of the Appalachian 

 range, and its analogy with other mountain ranges. Had this subject 

 come within the scope of this notice, I should »ot have been unmind- 

 ful of the labors of European and American geologists in this field of 

 investigation. In rocks of the same age in Great Britain, we have the 

 results of the admirable researches of Sedgwick and Murchison ; and 

 among those .who have investigated the question either in regard to 

 the laws governing this structure, or in the application of these laws 

 to the elucidation of structure in particular regions, may be named 

 Sir James Hall, Sir Henry de la Beche, Hopkins, Martin, Fitton, Wea- 

 ver, DuMONT, Studer and others ; while in our own country the same 

 subject has been more fully discussed under a new aspect, by Profes- 

 sors W. B. and H. D. Rogers. 



My constant devotion for more than twelve years to another de- 

 partment, requiring a great amount of detail and technicality, and 

 the constant dealing with minutiae, has left me little time for the cul- 

 tivation of the higher problems of the science ; and I must confess 

 myself, moreover, greatly in arrear, regarding the present aspect of 

 these and similar points of discussion. 

 [ Pal^ontoloot III.] 11 



