Not only are the waters in ceaseless motion, heaving to and fro under the influence of every passing breeze, borne hither and thither by mighty streams, disturbed by innumerable storms. But also the powerful attraction of the land, particularly of great mountain ranges, lifts the sea-surface in some regions hundreds of feet higher than in others. So that a ship, passing from the neighbourhood of a mountainous coast to mid-ocean, may be actually sailing or steaming downhill, actually descending a vast gentle watery slope.
Another question as to Ocean’s level has much exercised the minds of men.
Throughout the world, remains of sea-creatures in countless multitudes are found embedded in the substance of water-built rocks: sometimes the very rocks being made up of them. This, not only on the tops of lesser hills, but at the summits of mountains eight thousand feet high, twelve thousand feet high, sixteen or eighteen thousand feet high.
Very ancient remains they often are, certainly many tens of thousands of years old. But whatever their age may be, they echo and add to the story which is told by the rocks themselves.
From the rocks we learn that, once upon a time, long ago, they were put together, scrap by scrap, under water, not upon dry land. And from the fossil remains in those rocks we learn with equal certainty that, once upon a time, they lay under ocean-waters.
Fossil remains, buried in rocks, are of many kinds.
Not only relics of animals, or of parts of animals, such as teeth and bones and shells. Not only relics of sea-weeds and other ocean vegetation. Not merely the actual remains, hardened into stone; but also the casts or shapes of all such remains, found impressed in the substance of the rocks. The whole of these various records of the past must be included under the term “fossils.”
Firmer substances, like shells and bones, have become often transformed into actual solid stone. But softer living substances have more frequently passed out of existence, leaving only an impress or cast, which is filled up later by some other substance.
When upon high mountain-tops such fossils are found—the remains of sea-weeds and sea-creatures embedded in rock—the question must naturally arise, How could these ocean-inhabitants have found their way to such a height?
That the sea must once have flowed over them cannot be doubted. But how did it come about? Were those water-built heights under the sea, because in those times the land lay lower, or because the sea-surface stood higher?