Beach Rambles in Search of Seaside Pebbles and Crystals / With Some Observations on the Origin of the Diamond and Other Precious Stones

by John George Francis

ON THE LITORAL LABOURS OF THE OCEAN, AND ON SEASIDE SPORTS.

The more I consider the various phenomena occurring from time to time on the dry land, and the more opportunity I have of observing for myself simple facts in geology, the more I am struck at once with the truthfulness and the unexpectedness—if I may use such a word—of the assertion which Moses makes in the 1st chapter of Genesis, that the appearance of the “dry land” was due to “the gathering together of the waters unto one place.”

The assertion has an unexpected (à priori) character; for continents and tracts of dry land do not, on the face of them, suggest the idea of any recent presence of incumbent masses of salt water—perhaps miles in depth. But it is eminently truthful, for it is a key to many an abstruse problem in Nature, and a confirmation of every sound and enlarged view of the past history of this globe.

The ocean has been busily at work—in old times, inland; in later times, coastwise; in all times subterraneously. This last point is proved by the volcanoes, and that in a twofold argument. Such volcanoes as are now extinct, are so because they have lost all communication with the sea; such of them as are active, are so because they draw supplies of salt-water from the nearest part of the ocean, and this they can only do subterraneously.

But in speaking of the labours of the ocean, I shall confine myself to the seashore, as the scope of this little volume does not go beyond that region. The point where sea and land meet is the critical point for all observers of Nature. Here the disciple of geology should serve his apprenticeship, and if he cannot accumulate facts, and glean a kind of inspiration here, he cannot do so anywhere. Moreover here, better, we think, than in any inland scenery, Man can muse and meditate. That ever-varying curved line of moisture on the shore depicts the fluctuating changes which momentarily visit his “little day;” the tide running in is the flood of his early life; the tide running out is the ebb of his declining years; the vast sweep of the coast, backed by the upland ranges and everlasting hills, and itself only lost to sight in the far horizon, tells of a steadfast future, an immutable eternity.

Above all, those who desire to note epochs in the flight of Time, and to set up way-marks in the Earth’s chronology, must study the line of the sea-coast, the ancient and the modern, for here, if anywhere, the dial-plate is uncovered, and the shadow of the gnomon may be traced through some seconds of the enormous day which has witnessed the existence of the heavens and the earth.

I have already, in my opening chapter, remarked how the sea brings down, in the course of ages, many a pebbly beach from cliff and causeway. But I am far from assuming, therefore, that all the pebbles of a beach come from the land. The usual bottom of the sea is, indeed, no pebbly shore; but there are many submerged rocks of sandstone and oolite, out of whose ribs and crevices, from time to time, fossils may be washed, just as our own chalk-cliffs, the main resort of the siliceous pebbles, were themselves laid down in deep seas. And the salt water, which is always acting gradually to dissolve certain rocks, when it removes portions of these from the edges and promontories, will occasionally bring their contents to shore. But these results, although interesting to those who maybe searching after pebbles (and a deep-sea pebble is a prize), were not what I pointed at when I spoke of the labours of the ocean.

I have frequently walked the shore, and observed the colour of the waves, after what is termed a “ground swell,” which had lasted, perhaps, for thirty or forty hours. The cerulean hue is then gone, and to it has succeeded, in certain localities, an opaque chalky tinge, showing that the water is now heavily charged with lime. Also fragments of shells rolled together are united with heavy masses of sand, and sometimes of broken pumice-stone, and a kind of rough marl is rapidly formed, and left on the beach. After a gale, and succeeding “swell,” I have met with these imperfect boulders, varying in size from that of a man’s fist to some larger than his head. At the same time, any low ranges of littoral rocks become crusted over with the superabundant lime, being more than the waves will long hold in solution; and a coating is thus given to such rocks which is sometimes as hard as is the native limestone itself, a few weeks’ exposure to the sun and air sufficing to effect this.

Some fourteen years ago, I had an opportunity, when in Sicily, of examining a portion of the coast between Messina and Catania, and I regret that I did not avail myself of it more heartily. But I have seen M. Quatrefage’s book on this subject, and his observations, most carefully and laboriously conducted, may almost be said to close that part of the subject, as far as any prospect of eliciting fresh information is concerned. I think he measured some of the long reefs, and the evident increase by incrustation extended for many miles of the coast-line, and was of considerable thickness. I have observed the same “masonic” phenomenon off the coast of St. Andrews, in Fifeshire, when swimming out among the weedy rocks, and afterwards climbing to the shore. I then thought it was the work of marine insects, as I had heard of molluscs building causeways of tubes of limestone, but I incline now to think it was the sea doing it, as they say, at first-hand. The sea, however, does a great deal in the same line at second-hand, by means, chiefly, of two species of zoanthoid polyps. Of these little creatures, one kind constructs the bases of coral islands, and another the summits (at the least) of the madrepore reefs. It is impossible to doubt that by labours so patiently carried on, and so widely diffused, some beneficent purpose is aimed at and attained by Providence. Perhaps they operate, finally, to warn the shipping of adventurous merchants from entering certain dangerous bays and straits; and if the humble madrepore has got a bad name through this, as though he had made the danger, he certainly suffers unjustly, for what real difference, as to ultimate and assured safety, can a few inches more of water in such places make? Far better to raise an impassable bar across the way at once, and proclaim, “no thoroughfare!”

Then the ocean supplies a great market, much the greatest in the world. I do not know the proportion of persons in Central Europe who live on fish to those who live on meat, but I think, in both Northern and Southern Europe, the former exceed the latter. In Connemara, on the western coast of Ireland, and in the Scotch highlands of Argyle and Inverness, fish is decidedly the staple article of diet, as far as animal food is concerned. I believe the same is true of Cornwall and part of Devon. The herring, the pilchard, the haddock, the cod, and the salmon—to say nothing of the sole and other flat-fish—feed millions of persons, and, with the help of oatmeal, barley-cakes, and (in a good year) potatoes, feed them well. Shell-fish are also no mean item, and are sometimes the most refreshing of all dishes, especially at the supper-table. Now the sea, it must be remembered, does all this for man without harrowing, ploughing, or sowing. The fisherman’s net may be said to reap, that is all.