Permanent elevations of the land have been observed after some earthquakes. Thus, after the violent shocks of November 19, 1822, a great part of the coast of Chili was found to be raised several feet above its previous level, and after the great earthquake which occurred in New Zealand in the night of January 23, 1855, a large tract of land was found to be permanently upraised from one to nine feet. Before the shock there had been no room to pass between the sea and the base of a perpendicular cliff called Muka-Muka, except for a short time at low water, and the herdsmen were obliged to wait for low tide in order to drive their cattle past the cliff. But immediately after the upheaval, a gently sloping raised beach, more than 100 feet wide, was laid dry, affording ample space at all states of the tide for the passage of man and beast. These permanent elevations have often been attributed to the immediate agency of earthquakes; but Mr. Mallet proves this assumption to be a fallacy, as the impulse of the earthquake wave even right above the focus is utterly incapable of raising the level of the land by a height much more than instrumentally appreciable, and there is not the least evidence that any part of even this elevation is permanent. That earthquakes occur along with, and as part of, a train of other circumstances which do produce permanent elevation occasionally, and that earthquakes are probably always the signals that the forces producing elevation are operative, is another matter, with which that erroneous or loosely expressed view should not be confounded. The causes of earthquakes are still hidden in obscurity, and probably will ever remain so, as these violent convulsions originate at depths far below the reach of human observation. Mr. Mallet came to the conclusion that the depth of the original Calabrian shock in 1857 did not exceed seven or eight miles, and deduces from all the facts known as to the movements of earthquakes, that the subterranean points where the shocks originate perhaps never exceed thirty geographical miles, so that, even supposing the central nucleus of the earth to be fluid, they cannot possibly be due to the reaction of the internal ocean of molten stone upon the solid shell with which it is enveloped, but must have their seat within the latter. The existence of reservoirs of fused matter at various depths in the solid earth-rind is quite sufficient to account for all seismic and volcanic phenomena; for it is evident that whenever rain-water, or the waters of the sea percolating through rocks, gain access to these subterranean lakes of molten stone, steam must be generated, the pressure of which will in many cases rend and dislocate the incumbent masses.