Read Ebook: The mighty deep by Giberne Agnes

Font size: 10 px 15 px 20 px 25 px 30 px 35 px

Background color: BlackWhiteGrayLight GrayDark GrayDim Gray

Text color: BlackWhiteGrayLight GrayDark GrayDim Gray

Apply/Save settings

Ebook has 1075 lines and 58905 words, and 22 pages

But land-supplies grow pale and insignificant before the quantities which float in the ocean. It has been reckoned that, if the waters of the whole ocean could be dried up, the amount of salt left lying on the ocean-bed would be something like four-and-a-half millions of cubic miles.

In its make Water is always the same. Whether it be cold or hot, freezing or boiling, causes no difference. It consists of two gases, united; and the union is remarkable in kind. The two gases are not merely mixed together, as sand and sugar may be mixed. They are by the union changed into a fresh substance. For the time the gases exist no longer. In their stead, water has been formed.

And when the gases enter into this very close relationship, they do it always in the same manner. There is just so much of the one, and just so much of the other. One portion of hydrogen has to join with eight times as much by weight of oxygen--neither more nor less of either. The same is true, whether we are speaking of a great mass of water, or of the tiniest speck.

It is not actually correct to say, as is said above, that water "consists" of the two gases. So long as the water exists, the gases do not exist. And when, through the action of heat or electricity, the water is broken up and the gases reappear, then the water no longer exists. But at least we may say that it is the result of the uniting of those two gases, and that it can be made in no other way.

An interesting experiment has been tried. A certain amount of hydrogen gas and eight times as much of oxygen gas were weighed separately, by means of very delicate instruments. Then through great heat the two were caused to unite into water, and the water also was weighed. It was found to be just as heavy as the two gases together had been; and quite naturally so, since neither of the two gases had lost or gained in weight. This kind of union is called "chemical."

French people are fond of "eau sucr?." A lump of sugar is dropped into a glass of water, and it disappears. But it has not been destroyed. It has not ceased to be sugar. No mysterious union has taken place between the sugar and the water. Neither water nor sugar has changed its nature; and no fresh substance has come into existence in their stead. The water is there, as it was before. The sugar is there too, not visible, but to be found out by our sense of taste. It has only been separated by the water into such minute particles that we cannot see them. This is a case of mixing, not of chemical union.

When we think of the characteristics of Sea Water, as compared with Fresh Water, we have to do with simple mixing. As sugar floats, unseen but not untasted, in tea or coffee; so salt floats, unseen but not untasted, in ocean waters.

Such a thing as absolutely pure water is very rare. No matter how clear a stream may seem to us, it holds a vast number of specks of material, collected from earth and air. Once a scientific man had some, most carefully distilled, which seemed to be of crystal purity. But he put it under the strong beam of an electric lamp, and, alas, for human powers! after so doing he could only declare that the idea of purity was ludicrous. If it is so with distilled water, the less said the better about common drinking-water. It may be well for our peace of mind that we have not stronger sight.

Ocean-water holds about two hundred times as much dissolved material as ordinary fresh water. The different kinds of substances found in any particular water-supply determine the character of that water, making it sweet or sour or salt, rendering it health-giving or death-dealing.

Something has been said about the drying away of sea-water, and the leaving of salt behind. A remarkable instance of salt thus left is seen in the Rann of Cutch, a flat Indian plain, about a hundred and ninety miles long, and half as wide.

During the south-west monsoon the ocean waters are forced by powerful winds up the Gulf of Cutch to a considerable height, overspreading the Rann, which for a time is turned into a shallow lake. When dry weather comes, the water vanishes, partly retiring, partly evaporating; and a salt-strewn desert is left, varied by sand-ridges, green spots, and little lakes, but covered principally by "sheets of salt crust." My father, when there many years ago with his Regiment, noted down his impressions of the scene.

"From this spot"--the spot on which he stood--"the water is about eight miles distant, the intermediate space being a flat surface, entirely covered a quarter of an inch thick with salt in crystals, looking much like snow, in such quantities that it can be scraped up by the hand perfectly free from earth; and on all this space not a blade of grass to be seen."

The same task is carried on by the working of sun-heat, as by the fire under a kettle. All day long in a warm climate the sun's rays are busily at work, lifting from the ocean-surface a continuous stream of fine invisible vapour. The water is drawn up particle by particle, not in masses; and the sun's rays have no power to lift the ocean-salt, which remains behind, floating still in the sea.

But when a strong wind lashes the surface into waves, and rends the tops of billows into fine spray, it often carries a great deal of salt to a distance. We know how salt may be tasted on the lips miles inland, and how windows near the coast become encrusted with it in stormy weather. Moving air, like moving water, can carry weight; and it is thus, through the action of moving air, and not through the heat of the sun, that we have our health-giving breezes off the sea, laden with salt.

EARTH'S VAST OCEAN

"Thou great strong sea."--AUBERON HERBERT.

In these days we know the Ocean as one vast whole. Not like our early forefathers, standing on the brink, to gaze with awe-stricken eyes into mysterious distances, and to speculate upon the unknown.

Minor oceans do exist, certainly. We have the Atlantic, North and South; the Pacific, North and South; the Arctic, the Antarctic, and the Indian. Yet for us there is but one great world-wide OCEAN, encircling the Earth, every part being in connection with every other part.

A drop of water which to-day floats in southern seas may, months or years hence, have found its way by currents into the far north. A speck of ice, at this moment fast in the rigid embrace of polar berg or floe, may, months or years hence, be washing to and fro in tropical waters.

The outer Crust of our Earth, taking land and sea together, may be divided into three distinct parts. Like most such divisions in Nature, the one is often found to glide by gentle stages into another.

We have, first, Land, rising above the sea-level, and consisting of plains, undulations, hills, mountains. It covers altogether less than one-third of the Earth's surface, and it is called THE CONTINENTAL AREA, though Islands as well as Continents belong to it.

We have, secondly, the Ocean-floor under deeper parts of the Ocean; that which lies beyond a depth of about two miles. This division has been described as the "great submerged plain," and it comprises about one-half of the Earth's surface. It is known as THE ABYSMAL AREA.

We have, thirdly, a middle region, which may be spoken of as a kind of borderland under the sea, connecting the dry land with the greater ocean-depths. It amounts to about one-sixth of the Earth's surface, and it has been named THE TRANSITIONAL AREA.

The meaning of the word "Continental" needs no explanation; and the very word "Abysmal" carries its own sense. More, however, will be said in future chapters about those reaches of ocean known as the "Transitional Area."

A curious law seems to have governed the grouping of land and water. Putting aside innumerable small islands, scattered about, we find that the great mass of land clusters towards and round the north pole, with a water-and-ice-filled hollow for its centre. While, on the contrary, the greater mass of water may be said to cluster towards and round the south pole, with--so far as we can conjecture--a large extent of land for its centre. The conditions of north and south thus seem to be exactly reversed.

Not long ago it was believed that the ocean's floor might be a fairly close imitation of that which we see on land. The differences, however, have been found to be greater than was expected. Perhaps it is not surprising, when one thinks of the immense levelling power of water.

That must be a firm make of rock which can permanently resist the effect of sea waves breaking upon or near the shore. And even deeper down, where waves are not and currents may be slow, some movement must still exist, since the ocean is nowhere quite stagnant. Such movements, no matter how gentle, would tend to shift all loose and soft substances.

The ocean-bed is held to be generally flat, though with gradual slopes here and there, leading up or down to higher or lower levels. Many submarine mountains rear their heads, sometimes near the surface, sometimes above it. In places high mountain-ridges run for a long distance below the sea, with profound depths on either side; and these again often show their peaks, forming groups of islands.

Broad reaches of the ocean are between two and three miles deep, and here and there spots are found where the sounding-line goes sheer down three miles, four miles, five miles, even six miles, before touching bottom. These greater depressions have been named "Deeps."

At least fifteen of them are known in the Atlantic, and twenty-four in the Pacific; many of the latter lying close to islands. Some are long in shape, some short; some are broad, some narrow. One of the most profound, and almost the only one known to exceed five thousand fathoms, lies towards the south-east of the Friendly Islands. A depth there has been found five hundred and thirty feet beyond five geographical miles; and five geographical miles are equal to almost six of our common miles.

For a good while the notion was entertained that, probably, the loftiest mountain-peak on land, and the deepest depth in the ocean, would about match one another, reckoned from the sea-level. But this particular "deep" in the Pacific sinks two thousand feet lower than the topmost peak on Earth rises. Mount Everest, in the Himalayas, is twenty-nine thousand feet high; and this ocean-depth is about thirty-one thousand feet deep. Only one other equal to it has yet been discovered.

No abyss divides England from France. The "silver streak," though sufficient for purposes of defence, is comparatively shallow. All West Europe, indeed, rises from a plateau, reaching from Norway into the Atlantic, on no part of which is the water more than six hundred feet in depth. The "transitional area" in this case makes a true stepping-stone or ledge between dry land and ocean's abyss.

But another great plateau in the Atlantic, which may be called the "backbone" of that Ocean, is far from land, running roughly from north to south. It follows the outlines of the eastern and western shores, and rises often to within a mile and a half of the surface. On either side of the "backbone," which seems to be largely volcanic, is a deep trough, lying north and south, and varying in depth from two to four miles. This plateau unites Europe with Iceland; and it forms a bond between the Islands of the Azores, Ascension, and Tristan D'Acunha.

If by any means the whole ocean-surface could be lowered six hundred feet, remarkable results would be seen.

At once the British Isles would cease to be Islands. They would become a part of the Continent of Europe, joined thereto by dry land. The Hebrides, the Orkneys, the Shetlands, would share in this change. The Continents of Asia and North America would be united at the Behring Straits; Ceylon would find itself a part of India; Papua and Tasmania would be one with Australia; and all places hitherto on the coasts of different countries would find themselves six hundred feet above the sea.

Such a change in the position of the British Isles, transforming them into a Continental Country, would mean far-reaching consequences to ourselves as a People. One such consequence may be briefly given in the words of a recent newspaper article: "Dry up the Atlantic to the 100-fathom line, and in six months we should bear the load of Conscription as cheerfully and more efficiently than any nation in Europe."

Suppose that another great fall in the ocean-surface could follow. Not this time to six hundred feet, but to three thousand feet, below its present level. The resulting alterations would be still more sweeping. Not only Iceland and the F?roe Islands, but Greenland also--and not only Greenland, but the Continent of North America itself--would become one with the Continent of Europe, no longer cut off from the Old World.

A word as to measurements. Two kinds of "miles" have been mentioned. There is the ordinary "Statute mile," used in common conversation, which is 880 fathoms, or 1,760 yards, in length. There is also the "Geographical" or "Nautical" mile--the "knot" of our Navy--which is 1,013 fathoms or 2,026 yards in length.

The difference between the two is not far from one-eighth of a statute mile. Roughly, seven miles are equal to six knots. A fathom is six feet or two yards.

SUBJECT TO LAW

"Thou rulest the raging of the Sea."--PSALM lxxxix. 9.

"Nothing useless is or low, Each thing in its place is best, And what seems but idle show Strengthens and supports the rest."--LONGFELLOW.

Things are what they are in this world very largely because of the pull of opposing forces, and among such forces not one is more universal than that of Gravity. Many causes beside Weight have their share in making our Earth what it is; but if Weight were banished from our midst, the Earth as we know it would exist no longer.

The only way to get rid of weight would be by getting rid of Gravity. And since no force in Nature acts more steadily and incessantly than this, we are no more likely to get rid of it than we are to get rid of the world itself.

Gravity, or Gravitation, or Attraction--it is known by all these names. Sometimes it is called a Law; sometimes a Force. Neither term may be counted amiss. No law is worth anything without a sufficient force to back it up; and no force is worth anything unless it acts according to law. But we might almost as reasonably call this behaviour of things "an Obedience" as "a Law."

Each particle of each substance draws and is drawn by each other particle of every substance. And each body in the Universe, from a grain of sand to a sun, draws and is drawn by each other body, whether far or near. All these drawings are in obedience to that mysterious something--that force, or power, or influence--which has been named Attraction or Gravitation. So much we know; and beyond it we know very little as to the nature of the said "Attraction;" but we find that the outcome of it is Weight.

A larger and heavier Earth would bind down the ocean yet more strongly, while a smaller and lighter Earth would have a weaker grip. Easily as the sea is now stirred by every passing breeze, an ocean such as ours on a little world like the Moon or Mercury would be more rapidly agitated. The waves would leap higher with less cause.

So the Ocean, like the Land, is subject to law, knowing neither repose nor action except in obedience to Nature's forces.

Currents here and drifts there; breezes here and hurricanes there; all these disturb the calm of the sea. Only for a brief spell, in one part or another, is the pull of opposing forces so far balanced that the water can lie still. And at most the stillness is comparative. Even in a so-called "dead calm" gentle heavings to and fro will be found. Absolute placidity in the ocean is a thing unknown.

Even when the waters are at their stillest they are always being drawn steadily towards Earth's centre. A perfectly level ocean would mean each portion of its surface being equally distant from that centre. The ocean ever strives after this ideal, but never attains to it; yet, century after century that aim is pursued, with a perseverance which might afford a lesson to ourselves.

Despite all this change and restlessness, we talk of the ocean having a "level" surface. We picture it to our minds as being in outer shape the same as that of the Earth--a sphere. But this is not strictly true to fact.

Share on: WhatsApp @Hash Facebook Tweet