74 A CENTURY OF SCIENCE 



Wernerian Geology in North America. 



The Father of American Geology. Historical Geology 

 begins in America with William Maclure's Observations 

 on the Geology of the United States, issued in 1809. 

 This was the first important original work on North 

 American geology, and its colored geological map was the 

 first one of the area east of the Mississippi River. The 

 classification was essentially the Wernerian system. All 

 of the strata of the Coastal Plain, now known to range 

 from the Lower Cretaceous to Recent, were referred to 

 the Alluvial. To the west, over the area of the Piedmont, 

 were his Primitive rocks, while the older Paleozoic 

 formations of the' Appalachian ranges were referred to 

 the Transition. West of the folded area, all was Floetz 

 or Secondary, or what we now know as Paleozoic sedi- 

 mentaries. The Triassic of the Piedmont area and that 

 of Connecticut he called the Old Red Sandstone, and the 

 coal formations of the interior region he said rested upon 

 the Secondary. The second edition of the work in 1817 

 was much improved, along with the map, which was also 

 printed on a more correct geographic base. (For greater 

 detail, see Merrill, Contributions to the History of 

 American Geology, 1906.) 



Even though Maclure's geologic maps are much gen- 

 eralized, and the scheme of classification adopted a very 

 broad one, they are in the main correct, even if they do 

 emphasize unduly the rather simple geologic structure 

 of North America. This fact is patent all through 

 Maclure's description. Cleaveland also refers to it in 

 his treatise of 1816, and Silliman in the opening volume 

 of the Journal (1, 7, 1818) says : "The outlines of Amer- 

 can geology appear to be particularly grand, simple, and 

 instructive. ' ' Then, all the kinds of rocks were compre- 

 hended under four classes, Primitive, Transition, Allu- 

 vial, and Volcanic. It is also interesting to note here 

 that in 1822 Maclure had lost faith in the aqueous origin 

 of the igneous rocks and writes of the Wernerian system 

 as "fast going out of fashion" (5, 197, 1822), while 

 Hitchcock said about the same thing in 1825 (9, 146). 



The Work of Eaton. Amos Eaton, after traveling 

 10,000 miles and completing his Erie Canal Report in 



