OF THE APPALACHIAN CHAIN. 525 



tion, which raised the European coal strata from the aqueous bed in 

 which they were deposited, is a result of the highest interest in 

 the comparative geology of the two continents. It would seem 

 that the movement which produced so general and sudden a ces- 

 sation to the progress of the coal strata, led to grander changes in 

 the earth's surface than any disturbance since. Those displace- 

 ments of land and sea, which severally terminated the Silurian 

 and Devonian systems in Northern Europe, great as they truly 

 appear, were, after all, but local events ; not extending, except in 

 their indirect consequences, to the distant Appalachian shores, 

 and, it would seem, hardly to the oceanic tracts of the European 

 basin in Russia. Over how icide a limit these movements were 

 decidedly influential in the organic world, must soon become a 

 problem of the highest interest to our science. 



Analogous Phenomena of Axes in other Countries. 



A perception of the important and novel bearings of the curious 

 laws of structure here described, upon many points in geological 

 dynamics, has led us to examine, with deep interest, the valuable 

 and accurate labors of Fitton, Martin, De la Beche, Dumont, 

 Murchison, Sedgewick, Weaver, Hopkins, and other eminent 

 European geologists, in the expectation of finding in the phenom- 

 ena they describe, evidences of analogous laws. 



While studying, with this view, such memoirs, sections, and 

 maps as were within our reach, we have enjoyed no small grat- 

 ification in discovering, what we consider numerous striking 

 proofs of the prevalence of similar structural features in some of 

 the most interesting geological regions in Great Britain and on 

 the continent. 



Among these we would first mention the peculiarly interesting 

 districts of Wales, to which the admirable researches of Messrs. 

 Sedgewick and Murchison have, of late years, imparted so high a 

 geological importance. In the beautiful and elaborate work of 

 the latter geologist, the publication of which forms one of the 

 great eras in geological science, we think we discern very dis- 

 tinct proofs that the Cambrian and Silurian axes of Wales, pos- 



