‘These rocks, (sandstone, slate, and limestone,) however their properties may be found modified by future discoveries, will probably be found, with a proper allowance for local formations and disturbances, to pervade all that section of country, which lies between the Niagara and Seneca rivers, between lakes Ontario and Seneca, and between the Alleghany river and the south shore of Lake Erie, as general boundaries. All this section of country appears to be underlayed by a stratum of red sandstone, such as appears at the Gennessee Falls, but which is imbedded at various depths, as the country happens to be elevated above, or depressed below the level of the Niagara stratum, in which no inclination is visible. No order of stratification could have been effected by nature, which would have afforded greater facilities to the wasting effects of falling water, so visible as these Falls. The slate which separates the calcareous from the sandstone rock, by a stratum of nearly forty feet in thickness, is continually fretting away, and undermining the superincumbent stratum of limestone, which is thus precipitated in prodigious masses into the abyss below. The most considerable occurrence of this kind, that has recently taken place, is that of the _Table Rock_,[16] on the Canadian shore, which fell during the summer of 1818, disclosing a number of those crystallized substances, which have already been alluded to. By these means, the Falls, which are supposed by the most intelligent visitors to have been anciently seated at Lewiston, have progressed seven miles up the river, cutting a trench through the solid rock, which is about half a mile in width, and two hundred feet in depth, exclusive of what is hidden by the water. The power, capable of effecting such a wonderful change, still exists, and may be supposed to operate with undiminished activity. The wasting effects of the water, and the yielding nature of the rocks, remain the same, and manifest the slow process of a change, at the present period, as to position, height, form, division of column, and other characters, which form the outlines of the great scene; and this change is probably sufficiently rapid in its operation, if minute observations were taken, to imprint a different character upon the falls, at the close of every century.’