The Strange Adventures of a Pebble

by Hallam Hawksworth

CHAPTER X

(OCTOBER)

To-night the winds begin to rise

And roar from yonder dropping day;

The last red leaf is whirled away,

The rooks are blown about the skies.

—Tennyson.

THE AUTUMN WINDS AND THE ROCK MILLS OF THE SEA

Nothing looks more aimless, more unorganized, perhaps, than the long turmoil of the waves of the sea which begins in late autumn and continues through the winter months. If, with your nose well over the edge of a cliff, you look straight down, you will see something like this: With every forward leap of the surges the waters are divided and entangled among the rocks, and division after division is beaten back by the upright wall in front and the broken blocks of stone on this side and on that. On-coming waves, met by those recoiling, rise into mountainous, struggling masses of wild fury. The whole affair seems to be as clear a case of wasted energy as a Mexican revolution.

But if you watch the waves carefully and study them a little you will see underlying and controlling this apparent anarchy the wonderful engineering by which the machinery of the sea works out its appointed tasks. It is when the earth has gathered its harvests and laid down to its winter rest that the sea begins gathering harvests of its own, grinding up the rocks for food for the plants in its gardens, for new clothes for its shell-fish, and new soil for earth harvests in millenniums yet to be.

I. The Destroyer

On the face of it the case looks bad. The sea's chief business seems to be that of eating us up, or at least the lands on which we live. And this idea of it we find running through all literature and art. A very large number of the pictures of the sea, probably the majority, show it in wind and storm. And this is still more true of the famous sea pictures of literature. Shakespere, for example, makes some three hundred references to the sea, and nearly always, where he gives it a character, it is that of a monster, always hungry and never satisfied, a "wild, rude sea," a sea "raging like an angry boar"—and so back to Homer and forward to Kipling.

That the sea is constantly eating away the land cannot be denied, and to an extent that is delightfully alarming if, as did the little boy listening to the tale of the giants, we "like to be made nervous." It is said that England still rules the waves, but where she fronts the sea on the east the coast is being cut back at the rate of two to four yards a year, in spite of all that modern engineering skill can do. In the course of a thousand years the losses on all fronts have amounted to over 500 square miles. Each year carries off 1,500 acres more from the king's domains, to add them to the Empire of the Sea, "and he calls to us still unfed." On the east coast the blows dealt by the waves in severe storms are such that the land trembles for a mile back from the shore. "The earth," said Emerson,[47] speaking of the industrial greatness of England, "shakes under the thunder of its mills." So for ages it has shaken under the thunder of the mills of the sea.

[47] "English Traits."

Courtesy of "The Scientific American"

SEA-CLIFFS IN THE SCHOOLROOM

These dizzy cliffs and the wide sea beyond were made in the schoolroom in the same way that the glacier and the iceberg were made in [Chagter II].

Courtesy of "The Scientific American"

BEHIND THE SCENES

This apparent war of the sea upon the land is a war of machinery whose workings are curiously like the ancient war machinery of men. Without tools the sea is almost as helpless as man himself; and, as in man's history, its use of tools begins with the Stone Age. Where there is no stone-strewn beach or underwater shelf extending out from a cliff, the waves do little damage. They give only a muffled and (to the poetic ear) a baffled roar. But a sloping shelf along a rocky shore not only makes a kind of scaling ladder on which the waves can climb to great heights, but these waves are pitched forward with terrific force as they reach it from the open sea. As they come on they seize huge stones which they hurl against the cliffs. Even amid the wild voices of tempests one hears the boulders crashing against the walls. In storms of sufficient energy rocks of three tons weight are driven forward like pebbles. The action against the upper part of a cliff may be compared to that of one of those great stone-throwing engines of the Romans, while on the lower portion the drive suggests the battering-ram.

WHAT NEPTUNE KNOWS ABOUT WEDGES AND PNEUMATIC TOOLS

Where the waves strike into narrowing crevices in the rocks they act as wedges, prying the walls apart. In this form of the sea's destructive work we find also an application of a motive power which has come to play so important a part in modern engineering; namely, compressed air. Waves strong enough to handle big rocks not only dash them against the cliff, while the waves themselves drive into the crevices like wedges, but in so doing they force air into the crevices and compress it. This air, expanding as the waves fall back, forces out great blocks of stone which, in turn, are also used as weapons of assault.

And, as we look back in the history of the sea, we find that he long ago—the deep-laid schemer!—planted enemies within our very walls. Waves, even when armed with the heaviest missiles, can do comparatively little damage to walls in which there are no crevices. But there are few such walls. Usually even the hardest rocks have running through them those cracks which the geologists (with a fine sense of humor) call "joints"; or they have "bedding planes," the divisions between the rock beds. Both of these weaknesses in our defensive walls are, in a large degree, the handiwork of the sea; the bedding planes because rocks are so laid in the sea mills, and the joints because the wrinkling up and consequent cracking of the land rocks is the other end, as we learned in [Chagter I], of the down-wrinkling of the rocks under the weight of the sea.

In the very body of the rocks also is hidden a secret enemy; the salt left when they were made. And more salt is constantly being forced into the surface pores as the waves strike. This salt helps to dissolve and weaken the rock under the chemical action of the air, and the rains and the mechanical expansion and contraction of the surface with changes of temperature.

PLANING MILLS OF THE WINTER SEA

All the Great Powers of nature, "on land, on sea, and in the air," seem to be in open conspiracy against our peace. The evidence seems especially plain in late fall and winter, when the sea, contrary to the usual practice in war, carries on its most vigorous campaigns. Then come the winds for the great drives; then come the frosts that change the water wedges into expanding blocks of ice that, almost with the force of exploding shells, tear the walls apart. In winter are formed the great ice-fields that help in two ingenious ways to further the destructive action of the storm waves. In bays and smaller recesses in rocky shores, the ice has embedded in it fragments of stone which the sea has battered down. The constant plunge of the waves breaks up these ice-fields into sections which, with the embedded stones, become rude planing mills. Where a headland is sloping, these planers, driven back and forth by the waves, chisel the rock away as a planer chisels down a piece of steel upon which it has been set to work.

HOW STONES ARE CARRIED OUT TO SEA

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]

[48] Shakespere: "Titus Andronicus."

To make the thing seem doubly sure, let us reflect with Mr. Burroughs that the world is now probably in a time of spring, following the latest of the Ice Ages. If so, the water now locked up in snow-fields and glaciers among the mountain peaks will, before this summer of the centuries is over, all melt back into the sea. This alone will be good for a rise of some thirty feet in sea level.

Then, still later, we shall no doubt have another Ice Age, and the only thing that may save us from being frozen to death is the fact that we have previously been drowned!

II. The Builder

But it's all a bad dream; a delusion of the mind, and of the eye. We see these things—the destruction of the land, the invasions of the sea—but we do not see them as they are because we do not see far enough. Looked at broadly, and reading the story of it to the end, we learn that the whole relation of the sea to the land and its life and beauty is that of a builder and fatherly provider. Far from being the savage creature he has been pictured, Father Neptune seems to have the kindly disposition of old King Cole combined with the wisdom of King Solomon. Everywhere is evidence not only of the highest intelligence but of good will toward man and his brother tenants of the waters, fields, and woods.

THE TRUTH ABOUT THE SEA IS THIS

To begin with you remember it was the sea that helped put the world on the map. Of course, if we had not already learned in the story of how the continents came up out of the sea, that there is no cause for alarm, we might imagine that having been lifted up they might, by a reversal of the process, be lifted down again. Indeed, I find a writer in a popular periodical dealing in science stating that "every part of the sea floor becomes, in its turn, the shore line and is subjected to the wear of the waves." But, as a matter of fact, we know that the continents have finally got their land legs; that for ages the transgressions of the sea have been mainly confined to the continental margins; and that unless the earth's shrunken centre should, from some unimaginable cause, swell back to its old size, it is mechanically impossible for the entire bottoms of the vast reservoirs of the sea to be raised.

HARBOR ENGINEERING OF THE RIVERS AND THE SEA

In the mouths of certain rivers emptying into the sea the tides come rushing up in a roaring wave like this. When the tide goes out the water flows back again. This back-and-forth motion helps to broaden the harbor made by the river's mouth, as in the case of New York Harbor, which is the mouth of the Hudson. Owing to this tidal action the water of the Hudson backs up clear to Albany.

A GOLDEN GATE FOR FRISCO

The famous Golden Gate of San Francisco (so called because of the golden sunsets shining through), and its splendid harbor, made by the sinking of the land. The gate was originally cut by the waters of those two rivers that join and flow into the bay. What rivers are they?

HOW THE SEA HELPS MAKE GOOD FARMS AND BIG CITIES

Moreover the rivers, in the very act of wearing down the land and with it filling up the sea, help keep the land from being flooded, as it would be if something were not done. For, as we learned in the story of why the mountains border the sea the sediment poured in by the rivers helps raise the mountains and the land along the sea border. It is during the downward movement of the continental margins that most sediment is spread from the inpouring rivers because the dip of the land is greater and the swifter current not only cuts down the land faster, but carries the sediment farther out from shore. Here the new rock is made from old worn-out soil, and, since these new rocks when brought to the surface will in time decay, fresh soil is thus prepared for future generations. More immediate benefits of this sinking of shores and advance of waters are the harbors which have made great cities like New York and London, on or near the seacoast. These harbors are all the results of "transgressions," combined with the digging action of wave and tide.

Copyright by Underwood & Underwood

STONE TERRACES FOR THE GANNETS

This picture shows what the rising of the land and the architectural engineering of the sea did for the gannets on the coast of Canada.

TAKING A HINT FROM THE SEA'S SHORE ENGINEERING

But the sea builds shores as well as eats them. Its chief work in this line is the widening of the continental shelf by building it up with rock made of the sea's own grist from its shores, and the sediment poured in by the rivers. This work is not "delivered," so to speak, for millions of years, when the sinking shores begin to rise again, but the sea, in its wave work, does shore building of another kind that shows above the waters in the generation in which it is done. On wide, shallow beaches, storm waves break some distance from the shore, and, so losing their force, drop the sediment which they have stirred up, after carrying it forward only a little way. As a result of this repeated dumping, an embankment forms, broadening seaward in the middle and bending shoreward at the ends. A portion of the sea itself is finally cut out and enclosed by this embankment, thus forming a lagoon. Finally this lagoon is filled with material, washed from the land and by sediment brought in from the sea at high tide. Human engineers, taking the hint, now put the sea to work on similar undertakings of their own. An embankment is built enclosing an area of the sea; then the tides and the land wash do the rest.

THE DROWNED RIVERS THAT HELPED MAKE ENGLAND GREAT

Her fine harbors have helped to make England the great commercial nation that she is. Notice here the relation of her largest cities to the bay-like mouths of the drowned rivers and to the drowned valley north of the Isle of Wight.

HOW THE SEA TAUGHT SHORE ENGINEERING TO MEN

This is a salt marsh at mid-tide. How the sea itself adds such regions to the dominion of the land, and how human engineers, taking the hint, have put the sea to work, you will learn in this chapter.

The sea also works with the busy little corals in building reefs and islands. Corals can only live and build where the water is kept in constant and vigorous motion by current and wave. From the air imprisoned in the bubbles by the stirring and turmoil of the waves and particularly from the air in the white foam of the crests these little people get their oxygen. At the same time they absorb out of the water the food on which they grow. The sea not only feeds these little wards of its bounty during their busy lives, but extends their usefulness after death, either by cementing to the reef the coral, ground up by the waves, or in storms scattering it over wide areas, to be made later into the finest of limestone; and still later into the best of soils.

FATHER NEPTUNE FEEDING THE CORAL PEOPLE

See that line of breakers just below the horizon? That shows where Father Neptune is serving the little coral people with food and fresh air, as explained in the text.

We know also that the sea makes coal as well as stone in its rock mills; that the pressure of the overlying rock was in large part the source of the heat that changed the vegetation of the swamps, first into charcoal and then into coal.

The subject of what the sea has done and is doing for us is almost as endless as the seas themselves; and no doubt the reason the sea is never still is because it has so much to do. Nothing in earth's animate or inanimate nature exercises an influence to be compared in importance to that of the sea, not only upon the land, but upon the whole life which land and sea support; and even in what seem to be the most aimless of its movements it in reality acts with the precision of a machine.

III. The Artist

And in the making of the rock in its presses under the water, as well as in the grinding which takes place along the shores, the sea evidently has an eye to beauty as well as use. As originally formed, the conglomerates or "pudding-stones" are always laid nearest the shore because there the retiring waves and the rivers emptying into the sea drop the heaviest part of their load, including the pebbles. Next is dropped the sand which is pressed into sandstone and beyond this the finest particles of all, the ground-up soil, which becomes slate rock. Still beyond the zone of slate is deposited the lime from the shells of sea creatures who can live only in this clearer water, away from the muddy waters nearer the shore. These deposits make limestone. The result of this natural sorting process is that all the four kinds of sedimentary rock are always laid down in just this 1, 2, 3, 4 order and no other: (1) pudding-stone; (2) sandstone; (3) slate; (4) limestone.

Then, as a result of the transgressions of the sea, what was once a region of conglomerate may be later found far out under the sea and there is thus laid down over the conglomerate beds, strata of sandstone, slate, or limestone, depending on how far the sea advances. So we find rocks with all sorts of neighbors above and below; limestone above conglomerate, conglomerate above slate. These changes take place over vast regions and from the original uniformity in the arrangement of the rocks there necessarily results a similar uniformity in the results of this "shuffling," and no matter what changes may be made afterward by raising them up into shore cliff and mountain and by other earth movements, and by the endless reshaping by weather and wave, there still remains that underlying harmony which, with variety, gives to rocky shores their picturesque beauty.

Harmony and variety are necessary in all forms of art—pictures, literature, music—and the conditions governing harmony and variety are always found hand-in-hand in the art work of the sea and its helpers. The difference in texture in different kinds of rock, for example, and in different parts of the same rock, cause them to yield in different ways and degrees to the action of wave, wind and weather; so there is sure to be great variety in the shapes they take as they are worn away.

HARMONY, VARIETY, AND THE ART WORK OF THE SEA FAMILY LIKENESS IN ROCK FORMS

Yet, with all their differences, the shapes rocks take—sandstone compared with granite, for example—are so characteristic that one soon learns to tell a long way off what kind of rock a distant landscape is made of. There is inevitably a certain type resemblance, since all sandstone is of the same general texture and weathers in the same way.

NATURE'S BUILDING BLOCKS AND THE SEA

Then take the natural division into blocks made by joints in the rocks to which cliffs like the famous Castle Head at Bar Harbor owes its striking form. These blocks are so nearly true that you feel sure they must have been cut by stone-masons, and yet they have the variety which art demands; they have not the monotonous sameness of shape of the bricks in a wall. This is mainly due to the differences in the strains which cracked the original rock mass. So, from the beginning a sea-wall built by nature is more picturesque than a sea-wall built by man. And it goes on taking more and more picturesque shapes under the hammers of the waves. For the force of the waves, the angles at which they strike, the size and shape of the rock fragments with which they strike, these vary infinitely.

ETCHING, SCULPTURE, AND LANDSCAPE GARDENING

Equally true is this of other natural forces that shape the rocks; such as the daily and seasonal changes of temperature that chip away the mountain peaks and the faces of the cliffs, and the character and number of plants that grow on rocks where they can get a foothold and dying and decaying generate acids which help to etch the rocks away. Trees growing on rocks search out the cracks with their roots and, pushing in and prying them apart, help to change their form. And there is sure to be variety in the arrangement of the wild trees growing on rocks in the mountains and by the sea, since the seeds, being carried by the winds or by running water or by birds or four-footed creatures, fall in an endless variety of groupings. So of the shadows cast by the trees. These shadow masses, so different in shape, owing in part to the irregular arrangement of the trees and in part to the differences in shape of the trees themselves, protect portions of the rock, to a certain extent, against changes in temperature, while the bare rocks are fully exposed to it, so there results a corresponding variety in the result of the sun's work upon the rock. At the same time they help on the acid etching process, because in these shadowed spots there is more moisture and therefore more rapid decay.

The form of whole continents follows the same law. Take, for example, Europe. "The geological history of Europe," says Geikie,[49] "is largely the history of its mountain chains"; and the mountain chains, for all their picturesque variety, have also, and necessarily, a certain uniformity, because in the wrinkling of the rocks which made them the vast areas over which they now extend were all subjected to the same force—a big push from one side which crumpled up the earth's outer crust as a table-cloth is crumpled up when pushed forward against a book lying on it.

[49] Encyclopædia Britannica: article on Geology.

HOW THE VERY SCENERY PLAYS MANY PARTS

The ancient history written in the rocks, in the present relative positions of the strata, shows that four times a great mountain system has thus been raised across the face of what is now Europe; that three times large portions of these mountain ranges have been sunk under the sea and new rocks deposited over them; and that the mountains of to-day—the Alps, the Carpathians, and the rest—are the survivors of the fourth time up. Here we have another striking example of the fact that on the great stage of life the very scenery has its exits and its entrances!

But remember that in all these changes of scenery—in the crumplings and the foldings, and new rock deposits and the carving by the rivers and the frosts and the winds and the waves of the sea—we have certain similar materials, similarly arranged, stretching over vast areas, and the consequence is a certain uniformity and rhythm in the ups and downs of the landscape and in the changes worked in the walls of stone "where time and storm have set their wild signatures upon them."

HIDE AND SEEK IN THE LIBRARY

What would you think of seeing the leaves all out and the trees in bloom on Christmas Day? That happens right along, and the people who live in the lands where this occurs don't think anything of it, because this is in the Southern Hemisphere during the vacation season of the sea.

One peculiar thing about this spring and summer in the winter time in Africa is that when the leaves first come out they are not green at all. They are brown, red, and pink. Later on they turn green—just as any well-behaved leaf is supposed to do.[50] It's as if they got mixed in their dates and thought at first it was autumn and then woke up and said:

"Oh, yes, to be sure, this is spring! What are we thinking about?"

[50] Livingstone's "Expedition to the Zambesi."

Anyhow they turn from the autumn browns and reds to the appropriate green of spring, and the flowers come out and the birds begin to sing in the very season when our winter winds are loudest and the rock mills of the sea are roaring at their work.

In which Hemisphere, the Northern or the Southern, do the sea mills have most land to work on?

In Shakespere's "Tempest" you will find a description of a storm at sea that will take your breath away. Almost the whole of Scene 2, Act I, is in that terrible storm. In fact, the whole play, as the title of it indicates, is full of storm.

While you are looking for storms in Shakespere see what you can find in "Two Gentlemen of Verona," "Twelfth Night," "Midsummer Night's Dream," and "The Merchant of Venice."

Speaking of the sea still being in the Stone Age what do you know about the kind of tools man used in the Stone Age and how he got along?[51]

(You'll find that the story of the development of man, as dealt with in connection with the Stone Age, is part of the strangest story of all the strange stories of science. You will get a brief outline of it in this story of mine, in the last chapter.)

[51] Interesting books on this subject are: Starr's "First Steps in Human Progress" (Chautauqua Reading Course) and Clodd's "Childhood of the World." Osborn's "The Men of the Old Stone Age" is the latest and most comprehensive work on the subject.

How much more do you know about pneumatic tools than Father Neptune does? No doubt you've used a "pneumatic" tool of a sort yourself more than once—a tool for making a noise. Guess what. A pop-gun! Look up pneumatic tools, and you will find that the same thing that makes the pop-gun pop helps to build skyscrapers, locomotives, and steamships, and do a lot of other wonderful things.

In connection with the water wedges made by the sea you must remember that curious trick ice has when it freezes ([page 154]); otherwise you can't understand how it could act like a wedge.

Yes, and wedges, simple as they look, are almost as wonderful as levers; and you know what Archimedes said he could do with a lever.

The whole subject of machinery and particularly of "automatic" or so-called self-acting machinery[52] is fascinating. Find out about planing mills and how they work, particularly why they stop planing just when they are told to.

[52] As a matter of fact, the only machinery that is really automatic is the machinery of nature, of which what we have called "the machinery of the sea" is an example.

In connection with how the sea sometimes helps make harbors think of as many great harbors as you can, and then look on your geography map and see how many you have missed.

What character in "Titus Andronicus" says that about the man standing on a rock and watching the sea come to eat him up?

Your geography has a good deal to say about continental shelves; and with pictures. Do you remember?

Speaking of lands sinking under the sea you'll run into a world of interesting things if you look up the story of the Lost Island of Atlantis; about the Egyptian priest who first described it to Solon, the Greek lawgiver, as an earthly paradise where all the laws and everything else were just right.

And if you're of High School age you'll enjoy reading what Plato[53] and Homer[54] say about this ideal land.

[53] Timæus.

[54] The Odyssey.

Isn't it a striking thing how the big sea that can look so fierce takes such tender care of the little coral people? And what extraordinary folks these coral people are! Any good article about them will tell you worlds of interesting things. For instance, you will find the people of whole villages living together with only one backbone. I mean not one backbone apiece but one backbone among them all!

And they have the queerest way with their stomachs, a kind of co-operative digestion, of co-operative housekeeping. (Your mother will be particularly interested in this because it shows the "community kitchen" idea has been thoroughly tried out and it works! If you don't know about "community kitchens" among human housekeepers ask mother to tell you, and then you tell her what you found out about these strange little housekeepers of the sea.)