The “Shallow” zone is much more extensive, reaching to some ten millions of square miles. Its principal deposits are much the same as those of the tidal zone--muds, sands, gravels, pebbles. In parts of the Earth they also include volcanic and coral muds. Greater, far greater, far more widely reaching, are the regions of “Deep-Sea Deposits,” which cover more than one-half of the whole surface of our globe. In those cold and dark and silent workshops, hidden from the eyes of men, building goes on, very quietly, very slowly, through interminable ages. In those workshops are deposited divers materials--Red Clay, Red Mud, Blue Mud, Green Mud, Volcanic Mud, Diatom Ooze, Globigerina Ooze, and many others, forming Ocean’s carpet. Almost any of these muds and oozes may occasionally be found in the second division, but they more generally belong to the “Deep Sea.” CHAPTER XIV. HOW CHALK IS MADE “Peace, moaning Sea, what tale have you to tell, What mystic tidings, all unknown before? Whether you break and thunder on the shore, Or whisper like the voice within the shell, O moaning Sea, I know your burden well!” LEWIS MORRIS. “The tiny cell is forlorn, Void of the little living will.”--TENNYSON. One of the tasks carried on in Ocean waters is Chalk-Building. The “White Cliffs of Albion” and those also of Gaul are vast masses of chalk, containing layers of flint, and mixed with many other materials, but chiefly composed of the crumbling white substance, which is familiar to all who live near the North and South Downs. This formation stretches a long way. The heights of Salisbury are of chalk. The Chiltern Hills are of chalk. The Yorkshire Wolds are of chalk. It is found in Norfolk; it is found in Kent; it is found in Surrey; it is found in Sussex. There are chalk-beds in France, in Germany, in other parts of Europe--not to speak of Asia--which, with those of Great Britain, extend through many hundreds of miles. And wherever these masses of chalk are found, there we know that, once upon a time, the land lay under ocean-waves. For Chalk, like Sandstone, was not formed on dry land. It could not be formed on dry land. It was built--it could only be built--under the sea, to be in later ages uplifted as dry land. During those far-back days, when the chalk-beds of Europe were being made, a different state of things prevailed from that of the present. By far the greater part of Europe must have lain under water, from which the summits of the Alps, the Pyrenees, and other mountains emerged as groups of islands. Great Britain must have been chiefly or entirely hidden. So far I have spoken of sandstone and chalk together. But a marked distinction--a _vital_ distinction--exists between the two. In the mode of their building they may be alike. In the materials of which they are built they are utterly different. If a lump of chalk is examined by the chemist, its principal substance is found to be Carbonate of Lime.