In the first place, the earth's surface is a record of successive risings and fallings of the land. The accompanying picture represents a section of the anthracite coal-measures of Pennsylvania. Each of the coal deposits here shown, indicated by the black lines, was created when the land had risen sufficiently above the sea to maintain vegetation; each of the strata of rock, many of them hundreds of feet in thickness, was deposited under water. Here we have twenty-three different changes of the level of the land during the formation of 2000 feet of rock and coal; and these changes took place over vast areas, embracing thousands of square miles. All the continents which now exist were, it is well understood, once, under water, and the rocks of which they are composed were deposited beneath the water; more than this, most of the rocks so deposited were the detritus or washings of other continents, which then stood where the oceans now roll, and whose mountains and plains were ground down by the action of volcanoes and earthquakes, and frost, ice, wind, and rain, and washed into the sea, to form the rocks upon which the nations now dwell; so that we have changed the conditions of land and water: that which is now continent was once sea, and that which is now sea was formerly continent. There can be no question that the Australian Archipelago is simply the mountain-tops of a drowned continent, which once reached from India to South America. Science has gone so far as to even give it a name; it is called "Lemuria," and here, it is claimed, the human race originated. An examination of the geological formation of our Atlantic States proves beyond a doubt, from the manner in which the sedimentary rocks, the sand, gravel, and mud--aggregating a thickness of 45,000 feet--are deposited, that they came from the north and east. "They represent the detritus of pre-existing lands, the washings of rain, rivers, coast-currents, and other agencies of erosion; and since the areas supplying the waste could scarcely have been of less extent than the new strata it formed, it is reasonably inferred that land masses of continental magnitude must have occupied the region now covered by the North Atlantic before America began to be, and onward at least through the palæozoic ages of American history. The proof of this fact is that the great strata of rocks are thicker the nearer we approach their source in the east: the maximum thickness of the palæozoic rocks of the Appalachian formation is 25,000 to 35,000 feet in Pennsylvania and Virginia, while their minimum thickness in Illinois and Missouri is from 3000 to 4000 feet; the rougher and grosser-textured rocks predominate in the east, while the farther west we go the finer the deposits were of which the rocks are composed; the finer materials were carried farther west by the water." ("New Amer. Cyclop.," art. Coal.) DESTRUCTION OF POMPEII