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 palaeozoic 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 palaeozoic 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 The history of the growth of the European Continent, as recounted by Professor Geikie, gives an instructive illustration of the relations of geology to geography. The earliest European land, he says, appears to have existed in the north and north-west, comprising Scandinavia, Finland, and the northwest of the British area, and to have extended thence through boreal and arctic latitudes into North America. Of the height and mass of this primeval land some idea may be formed by considering the enormous bulk of the material derived from its disintegration. In the Silurian formations of the British Islands alone there is a mass of rock, worn from the land, which would form a mountain-chain extending from Marseilles to the North Cape (1800 miles), with a mean breadth of over thirty-three miles, and an average height of 16,000 feet.