A no less curious feature of sea engineering is the use of ice-fields as "conveyors." During the spring, summer, and autumn the masses of stone which the sea brings down from the cliffs on its occasional busy days—that is to say on days when the winds are high—pile up and so form a kind of bulwark against further attacks. But when in winter these stones become embedded as above described, strong offshore winds carry the ice-fields, stones and all, out to sea. Then, on shore, wind and wave take up their work again unchecked. All along the rocky shores of the Atlantic, as far south as New York State, beyond which no rock walls come down to the shore, all these interesting things may be seen by the traveller.
Another phase of this team-work of natural forces in feeding the land to the sea is that steady advance of the waters upon certain shores. As if science herself had joined literature and art in giving the old sea dog a bad name, these advances are called in the language of geology, "transgressions of the sea." These transgressions are caused in part by the gradual sinking of the land and in part by the rising of the waters. It is not possible always to tell which agency is at work. Often both may be. One thing about the rising of the waters themselves might be looked at as particularly alarming. The rivers, which, of course, are parts of one great water system, whose centre and prime mover is the sea, are not only constantly wearing the land down toward sea level but raising the sea level by the inpour of vast quantities of ground-up land. Even as matters stand, the amount of water in the sea bowls is so great that if all lands were at the present sea level they would be covered everywhere to a depth of two miles. Wind-borne dust from the surface of the land and from volcanic explosions also, in time, amounts to a pretty sum; and, of course, helps makes the waters of the sea rise upon the land.
WEARING DOWN THE LAND AND FILLING UP THE SEA
Already the sea has advanced a thousand feet or more upon the coasts of Maine, to take one instance; and the whole ragged outline of Europe is due to the same cause. Let this sort of thing go on and it is easy to see that it will only be a question of a few millions of years when New York, London, and other centres of busy life will be buried like the wicked cities of the plain.
And if, to help complete this picture of desolation, we for a moment forget what we learned about the life insurance carried by the continents, we can imagine how they too will disappear. And the Last Man thus:
For now I stand as one upon a rock
Environed with a wilderness of sea,
Who marks the waxing tide grow wave by wave
Expecting ever when some envious surge,
Will, in his brinish bowels, swallow him.[48]