"Strata were upraised and flexed into great (olds, some of the folds a score or more of miles in span. Deep fissures were opened in the earth's crust," like the fiords or great rock-cracks which accompanied the Diluvial or Drift Age. "Rocks were consolidated; and over some parts sandstones and shales were crystallized into gneiss, [1. Dana's "Text-Book," p. 150.] {p. 432} mica-schist, and other related rocks, and limestone into architectural and statuary marble. Bituminous coal was turned into anthracite in Pennsylvania."[1] I copy from the same work (p. 153) the following cut, showing the extent to which the rocks were crushed out of shape: ### SECTION ON THE SCHUYLKILL, PENNSYLVANIA. _P, Pottsville on the coal-measures; 2, Calciferous formation; 3, Trenton; 4, Hudson River; 5, Oneida and Niagara; 7, Lower Helderberg; 8, 10, 11, Devonian; 12, 13, Subcarboniferous; 14, Carboniferous, or coal-measures._ These tremendous changes were caused by a pressure of some kind which came from the east, from where the Atlantic Ocean now rolls. "It was due to a _lateral_ pressure, the folding having taken place just as it might in paper or cloth under a lateral or _pushing_ movement."[2] "It was accompanied by _great heat_ which melted and consolidated the rocks, changed their condition, drove the volatile gases out of the bituminous coal and changed it into anthracite, in some places altered it to graphite, as if it had been passed through a furnace."[3] It also made an almost universal slaughter of all forms of life: "The extermination of life which took place at this time was one of the most extensive in all geological history; . . . no fossils of the Carboniferous formation occur in later rocks."[4] [1. Dana's "Text-Book," p. 152. 2. Ibid., p. 155. 3. Ibid., p. 155. 4. Ibid., p. 157.] {p. 433} it was accompanied or followed, as in the Drift Age, by tremendous floods of water; the evaporated seas returned to the earth in wasting storms: "The waters commenced the work of denudation, which has been continued to the present time."[1] Is not all this a striking confirmation of my theory? Here we find that, long before the age of man, a fearful catastrophe happened to the earth. Its rocks were melted--not merely decomposed, as in the Drift Age,--but actually melted and metamorphosed; the heat, as in the Drift Age, sucked up the waters of the seas, to cast them down again in great floods; it wiped out nearly all the life of the planet, even as the Drift Age exterminated the great mammals; whatever drift then fell probably melted with the burning rocks. Here are phenomena which no ice-sheet, though it were a thousand miles thick, can explain; here is heat, not ice; combustion, not cold; and yet all these phenomena are but the results which we have seen would naturally follow the contact of the earth with a comet.