If my reader will now suppose this sand of the Indian river to be hardened into sandstone, the mud in like manner compressed into shale, and the peat beds chemically altered into coal, can he fail to perceive the striking analogy between the section thus displayed and those already given from the Mid-Lothian and Cape Breton coal-fields? The differences between the ancient and modern strata are not in kind but in degree. The Scottish series reaches to more than six times the thickness of the Indian one, and the coal-seams in the one exceed in individual thickness the peat-beds in the other. We must remember, however, that the climate of Hindustan is not remarkably favourable to the accumulation of vegetable matter, the heat being so great that the plants decay almost as rapidly as they grow. And it should likewise be borne in mind, that were the conditions of subsidence and of the gradual accumulation of sedimentary matter to continue even in the same ratio as heretofore, the Ganges might, in the course of ages, heap up a series of stratified sands, clays, and peat-beds, many thousand feet in thickness, and many thousand square miles in extent, rivalling, or perhaps surpassing in depth, the largest coal-field in the world. The parallelism between this delta and an ordinary coal-field holds singularly close, not merely as regards the nature of the stratified deposits. The alluvial plain of Bengal has undergone a process of subsidence to an unknown depth, whereby successive areas of terrestrial vegetation have been carried down to be entombed beneath fluviatile sand and mud. It is likewise subject to the more sudden operation of earthquakes, whereby large tracts of country become permanently altered, and changes are effected on the direction, rapidity, and detritus of the streams. It is, moreover, liable to wide-spread inroads of the sea, which sometimes covers cultivated districts to a depth of several feet, laying waste the fields and destroying the inhabitants. These and other features help us to understand the origin of such vast masses of sedimentary strata as those of our coal-fields, where terrestrial, fluviatile, and marine remains alternate in rapid sequence, or sometimes occur together.