224 Prof. Sillimmi's Address before the 



volcanoes and other vents, to reveal the deep secrets of the 

 earth."* 



From all these sources, we have derived a competent know- 

 ledge of the structure of the crust of the earth — of that portion 

 with which we are immediately concerned. Every extension of 

 geographical research, especially as prosecuted in modern times, 

 by the English, the Russians, the French, and the Americans, 

 whether in overland or in maritime expeditions — to the islands 

 of the Indian, Southern, and Pacific oceans, or towards the op- 

 posite poles — conspires to confirm the conclusion that a grand 

 uniformity and simplicity of design characterize the geological 

 structure of all countries, however remote. There is the same 

 order in the arrangement of the rocks — there are the same asso- 

 ciations of strata and of minerals — the same fossils marking sim- 

 ilar geological epochs ; and therefore we infer that a uniform code 

 of laws has been prescribed for the whole. 



Coal, with its characteristic fossil vegetables, is found in Mel- 

 ville Island, far within the northern polar circle, and Captain Ross, 

 in 78° of south latitude, has recently discovered a powerful vol- 

 cano in great activity, amidst the eternal snows and glaciers of 

 the southern pole, flashing vividly upon the frozen Antarctic sky, 

 from a crater at the elevation of 12,500 feet — a truly polar Ten- 

 eriflfe.f 



Thus it appears that the polar lands of both hemispheres are 

 glowing with intense igneous action. Iceland is a vast classical 

 region of volcanic fire ; the antipodal polar zones are sustained, it 

 may be, upon subterranean seas of melted rock, covered by moun- 

 tains and glaciers of eternal ice and snow, through which the 

 internal fires force, here and there, an opening, and thus reveal 

 the secrets of the nether abyss. 



OF ITS PROGRESS AND PRESENT CONDITION, ESPECIALLV IN THE UNI- 

 TED STATES. 



Within our present limits of time, it would be in vain that 

 we attempt even a sketch of a general history of our science, 

 and the effort would be quite superfluous, as the work has been 

 admirably done to our hands, in the introduction to Mr. Lyell's 

 Principles of Geology. I trust I shall therefore be excused for 



* Loc. cit, 



t London, Edinburgh, and Dublin Philos. Mag. for Feb. 1842. 



