WORKS AND MEMOIRS ON MOUNTAIN-MAKING, ETC. 831 



Conclusion. — The causes of the earth's movements, which have 

 been considered, appear to explain the evolution of the prominent 

 features of the globe ; and the special history made out for North 

 America may be safely regarded as an example of what will hereafter 

 be accomplished for all the continents. 



But Geology, while reaching so deeply into the origin of things, 

 leaves wholly unexplained the creation of matter, life, and spirit, and 

 that spiritual element which pervades the whole history like a proph 

 ecy, becoming more and more clearly pronounced with the progressing 

 ages, and having its consummation and fulfillment in Man. It gives 

 no cause for the arrangement of the continents together in one hemi- 

 sphere (p. 10), and mainly in the same temperate zone, or their sit- 

 uation about the narrow Atlantic, with the barrier-mountains in the 

 remote west of America and in the remote east of Europe and Asia, 

 thus gathering the civilized world into one vast arena (p. 29) ; it does 

 not account for the oceans having, in extent and depth, that exact 

 relation to the land which, under all the changes, allowed of submer- 

 gence and emergence through small oscillations of the crust, and hence 

 permitted the spreading out of sandstones and shales by the waves 

 and currents, the building up of limestones through animal life, and 

 the accumulation of coal-beds through the growth of plants, — and 

 all in numberless alternations ; nor for the various adaptations of the 

 system of plants and animals to the wants of the last species in that 

 system. Through the whole history of the globe, there was a shaping, 

 provisioning, and exalting of the earth, with reference to a being of 

 mind, to be sustained, educated, exalted. This is the spiritual element 

 in geological history, for which attraction, water, and fire have no ex- 

 planation. 



The following are the titles of important works and memoirs on mountain-making, 

 on the origin of the earth's structure, and on cleavage and foliation. One is added that 

 was omitted under the subject of Volcanoes. 



Since the Taconic system has been recognized by some geologists as including an 

 independent range of elevations and disturbed rocks, extending uninterruptedly from 

 Maine to Georgia, and even from the Taconic mountains around the world, the titles of 

 the more prominent papers on this system, pro and con, are added. 



1. British and European. 



Gregory Watt: Observations on Basalt, etc., Phil. Trans., 1804, p. 279; gives a 

 detailed account of the melting of 700 pounds of basalt from Rowley-Rag (G = 2-743), 

 to glass, and of its becoming, on slow cooling, a gray, crystalline-granular mass (with 

 G. =2-934-2-949) consisting of spherical concretions, many two inches in diameter, 

 and having a somewhat radiated structure (which was mostly lost with the slowest cool- 

 ing) ; and of the adjoining concretions being often rendered hexagonally prismatic 

 from contact, whence he infers the concretionary origin of basaltic columns. 



James Hutton : Theory of the Earth, R. Soc. Kdinb., 1778; 8vo, 1795; attributes 

 mountains to subaerial denudation after an elevation of a region by the earth's central 

 heat 



