Of all the physical features of our continent, that which most powerfully arrests the attention is the noble chain of the Alps, with its wide-spreading system of subordinate mountain-ranges; and among the series of grand events, which by the researches of the geologist are demonstrated to have taken place on this our own portion of the globe, there are none more striking and conspicuous than those manifestations of subterranean forces to which the vast mountain-masses in question owe their origin.