« 이전계속 »
a score of voyages at most; but by the aid of these charts each may have the full benefit of the knowledge gleaned by a half thousand others.
The grand series of investigations thus set on foot in this country in due course of time attracted attention abroad. Our own government early entered into the scheme, by ordering all our naval commanders to make the required observations, and by giving it every furtherance required. Proposals for like co-operation were made by the maritime nations of Europe, and in August and September, 1853, a conference was held at Brussels for the purpose of devising and perfecting a uniform plan of operations. The governments of Great Britain, France, Russia, the Northern Powers, and all the maritime nations of Europe were represented by competent delegates. Our own government was represented by Lieutenant Maury. A plan of mutual assistance was adopted;, and the conduct of the operations was placed under the solemn sanction of public law. No war that might arise was to interrupt them. A Russian vessel enlisted in the work may be taken and become a prize to its captors; but the observations made in pursuance of this plan are sacred, and are to be transmitted unharmed to our National Observatory. Thus, whether in war or peace, new acquisitions will continually be made, new conquests won; conquests defiled by no blood, stained by no rapine; won by no nation at the expense of another: conquests won from the elements of nature for the well-being of all men forever.
Valuable as are the results of this grand series of observations in a commercial and pecuniary point of view, their scientific aspects are of still higher and more general interest. New light has been shed upon some of the most mysterious problems in the economy of nature; such, for example, as the great atmospheric and oceanic currents, by means of which a perpetual interchange is kept up between the temperature of the tropical and polar regions. It is not too much to hope that, when the whole area of the ocean has been covered over with a net-work of observations, materials will be accumulated, from which may be framed a complete and satisfactory theory to explain the currents in the ocean, that hitherto Hnrevealed mystery of the watery world.
Enough has already been accumulated to show that there is a constant current of cold water setting from the poles of the earth toward the equator, and consequently a counter current of heated water from the equator to the poles. Each of these counter currents is in turn a surface and an UDder current.
As a starting point in the investigation, may be taken the great Equatorial Current which we find flowing from the vast expanse of water around the Antarctic pole. It pours a constant flood of cold water northeastward toward the western shores of South America. Encountering the coast of America, it is divided and turned from its course, one portion rounding Cape Hom, often baffling for days and weeks those navigators who endeavor to pass from the Atlantic into the Pa
cifie. The main body, however, turns due north, skirting the shores of Chili and Peru, whence it turns again westward into the bosom of the Pacifie, cooling the ocean that encircles the island groups of the South Seas, and passing onward through the Pacific into the Indian Ocean. In the north, it is broken against the Chinese coast, Australia, and the islands of the Indian Archipelago, through which a large portion makes its way into the Indian Ocean. Passing down the eastern shore of Africa, it doubles the stormy Cape, misnamed of Good Hope, skirts the coasts of Guinea, and the dolorous region cursed by the slave-trade, abhorred by God and man, and enters the great caldron of the Bight of Benin, into which, on the very line of the equator, pours the current of the mysterious Niger.
Here the waters, raised to a high temperature by the fierce rays of a vertical sun, take their way westward, across the Atlantie, forming the Equatorial Current of the Atlantic Ocean. The coast of Brazil protrudes into tho Atlantic like a wedge, having Cape Saint Roque as its apex. Upon this wedge the current splits, one portion turning to the south, giving the coast of Patagonia and the Falkland Islands a European climate. The other portion goes to the north, a part diffusing itself over the Atlantie, toward the south of Europe, while the remainder, following the line of the coast, passes through the Caribbean Sea, and enters the Gulf of Mexico; whence it emerges with augmented volume as the Gulf Stream. In thus tracing this great current, its general direction only has been given. In all parts of its course it meets counter currents, which sometimes deflect it from its course; and sometimes it dives under, so that the surface current tends in precisely the opposite direction from the one indicated.
The Gulf Stream is more accurately known than any other of the ocean currents. It emerges from the Gulf of Mexico as a well defined river of warm water, inclosed between banks of cold water. For hundreds of miles the line between the blue waters of the Stream, and the greenish waters of the surrounding ocean, is as visible to the eye as the line between a river and its banks. So sharp is the line of separation that a vessel is not (infrequently beheld with one part manifestly in the blue water, and the other part in tha green. Long after the difference in color has become imperceptible, the thermometer tells with unerring certainty when a vessel has passed from the cold waters of the Atlantic into the warm current of the Stream.
As it emerges through the Straits of Btmini, it is thirty-two miles wide, probably twelve or fifteen hundred feet deep, and flows at the rate of four or five miles an hour. Careful caleulations show that it conveys from the Gulf of Mexico an amount of water three thousand times greater than that brought into it by the Mississippi; and that it carries away to the north a supply of heat sufficient to keep in a fluid state a river of molten iron as large as our great "Father of Waters." It follows the line of the coast, st a considerable distance, until it reaches Cape Hatteras, by which time it has spread to a width of about one hundred and seventy-five miles. From this point it rapidly diffuses itself, less however by actually mixing its waters with those of the surrounding ocean, than by flowing over them, as a body of oil would flow over the surface of a lake. Its course now veers almost directly east, standing straight across the Atlantie, covering the surface of the ocean with a warm mantle which protects the coasts of Europe from the extremes of temperature due to their northern latitude. When the stream reaches the neighborhood of the British islands, it is divided, one portion tending toward the polar regions, giving to Spitzbergen, in latitude 80°, a mean temperature as high as that of the shores of the central part of Hudson's Bay; to Iceland it gives a climate as warm as that of Newfoundland. It enables the Lapland peasant to cultivate his barIcy in a latitude which upon the Western Continent is doomed to perpetual sterility. The green shores of Ireland are on the same parallel with the ice-bound coast of Labrador; Paris lies to the north of Quebec; the crowded port of Liverpool is as far north as those bleak countries where the Esquimaux build their snow houses, and patiently watch the rising of the seals from their breathing holes in the ice.
All this difference between the climate of the two hemispheres—a difference in favor of the Eastern Continent fully equal to that produced by twenty degrees of latitude, is the gift of the northern branch of the Gulf Stream; while the other branch is equally bountiful to the countries of Southern Europe. To France and Spain it gives the vine and the olive. Thus long before the bold Genoese turned his prow toward the Westam World, that Western World had been bestowing upon the natives of Europe the blessings of a mild and equable climate.
But whence comes this immense body of water thus perpetually forced out of the Gulf of Mexico 1 Where are the hidden fountains of this great ocean stream, by the side of which the mightiest rivers of the land are but tiny brooks? What force impels its warm currents straight through the surrounding waters, and spreads them abroad over the surface of the ocean? The water borne in this Stream from the Gulf of Mexico must somehow find its way back; for that great basin shows no signs of being emptied; while the northern seas into which it pours its mighty current never overflow.
The Gulf Stream was once looked upon as a simple prolongation of the Mississippi. This supposition was conclusively set aside by the demonstration that it would require three thousand rivers like the Father of Waters to bring into the Gulf the amount of water borne out of it by the Gulf Stream; even laying quite out of account the immense evaporation continually taking place from such a mass of water lying under so warm a sun.
It was then suggested that the waters of the ocean were driven into the Gulf by the trade
winds, and found their way out by the only practicable channel. The Gulf Stream was declared to be like a river on the land descending from a higher to a lower level, and thus gaining the impetus by which it forces its way down to the north. But it was soon found that no such difference of level existed; or rather that the bed of the Stream, instead of descending to the north, actually ascended at a rate of inclination greater than the average descent of the Amazon or the Ganges.
Still further observations showed that while the Gulf Stream was pouring a current of warm water to the north, a counter current of cold water was at the same moment running beneath and beside it directly into the Gulf. Both streams, thus flowing in contrary directions, could not be running down hill. Vessels drifting northward near the Great Banks of Newfoundland not unfrequently encounter huge icebergs making their way to the south directly in the teeth of both wind and the surface current of the Gulf Stream. They sometimes rise hundreds of feet above the water; and philosophy has demonstrated that for every* hundred feet they rise above the surface, they must sink a thousand feet below. They therefore penetrate through the superficial current flowing northward, down into a submerged southern current, far enough for its force to prevail over the one which was tending to bear them northward. Ships, drawing but a few feet of water, never sink into this under current, and so partake only of that which flows upon the surface.
More minute observations showed that this ice-bearing current from the Arctic regions encountered the head of the Gulf Stream near the Banks of Newfoundland, and that it was there split into two portions, the one running inshore between the American coast and the Gulf Stream; while the other plunged under and flowed beneath the warm surface current into that very Gulf of Mexico, from out of which the other current was pouring.
Here then was a solution of one portion of the problem of the Gulf Stream. The waters which pour forth to the north, heated from the great caldron of the Gulf, flow into it, as an under cu»rent, from the northern regions. But the other branch of the problem seemed by this very solution to be involved in still deeper mysteiy. What was the impelling force that set in motion these two opposite currents, thus flowing side by side, and over and under each other?
For the solution of this problem Lieutenant Maury has furnished some suggestions in which we are confident will be found the germs of the true theory by which will be explained not only the Gulf Stream, but all of the other currents of the ocean.
Let us, in order to elucidate this theory, suppose that by some process all the water of one portion of the sea—the Gulf of Mexico, for example—were suddenly to become of less specific gravity than the other: or we will say, converted into oil. What would be the consequence 7 Why, the surrounding waters would press upon the lighter fluid, and force it out in any direction where there was no obstacle; spreading it abroad over the surface, while the heavier fluid would pour in as an under current to supply the place of that forced out, keeping the whole surface at a uniform level. Now let us further suppose that the oil as it approached the pole was changed to water again, while that which flowed into the Gulf was constantly changed into oil, and so on in continual succession; we should then have just the phenomenon of the Gulf Stream: an upper current of light fluid continually pouring out from the Gulf, and an under current of heavier fluid just as constantly pouring in.
Our supposition corresponds to the fact in all essential particulars. Water, withincertain limits, expands by heat, therefore becoming lighter; and contracts by cold, so becoming heavier. The operation of heat alone would simply cause a general current of warm water to flow on the surface from all equatorial regions toward the poles, to be replaced by as constant and uniform an under current from the poles to the equator.
This is precisely what takes place in respect to the other great fluid body, the atmosphere. Along the line of the equator, extending for some degrees on each side, is a belt of atmosphere in which there are no constant winds. Here the air heated by the vertical rays of the sun becomes rarified and rises. From each side of this equatorial belt the air of a lower temperature rashes in to supply the partial vacuum; thus forming the trade winds, which blow steadily from the direction of the northern and southern poles. These great atmospheric currents aro as steady and uniform in their course as is the current of a great river seeking its way to the sea. The storms and hurricanes, tho typhoons and whirlwinds, which lash the surface of tho ocean into waves, and strew its bottom with the wrecks of navies, bear no greater proportion to the steady and equable flow of tho trade winds, than the eddies and whirls in the Mississippi do to the general direction of its current.
Now were the rays of a vertical sun the only force that disturbs the equilibrium of the ocean, and were the free movements of the waters unobstructed by the conformation of the bottom and shores of the ocean, we should have oceanic currents answering precisely to the trade winds: that is, a constant surface flow of heated water from the equator to the poles, with as constant an under current of cooler water from the poles to tho equator.
But there is another disturbing force which comes in to modify, and in some instances greatly to augment this of which we have been speaking.
The water of the ocean contains in solution a large amount of saline and other matter, which, as is well known, render it considerably heavier than an equal volume of fresh water. From certain portions of the ocean—those especially over which the trade winds blow—a much larger quantity of water is taken up by evaporation than is returned in the shape of rain, But fresh water only is taken up, leaving behind all the salts held
in solution; so that the remaining water is salter, and therefore heavier than it was before. This change takes place only on the surface; and the thin layer of water thus rendered heavier sinks by its weight, while a portion of fresher and lighter water rises to the surface to take its place. A continual current up and down is thus produced in the waters between tho tropies. In the mean while, in the regions to the north—at the poles especially—more water is deposited from the atmosphere than is taken up by evaporation. This water is all fresh, and consequently it tends to make the polar waters lighter than they otherwise would be. So that, owing to saltness, evaporation, and precipitation, we have a great chango continually wrought in the specific gravity of the water of the ocean. And as was shown, whenever such a chango is wrought, two counter currents are of necessity set in motion, the one at the surface and the other in an opposite direction below the surface.
The saltness of the ocean, it may therefore ha fairly presumed, contributes in no small degree toward causing the ceaseless currents by which the waters of every sea are mixed and mingled together. The course of investigation now in progress renders it probable that the currents of the ocean are primarily owing to these changes continually going on in the specific gravity of the waters of different portions.
Thus the currents of the atmosphere and of the ocean are brought under one law. They both are traced back to the power of gravitation. The same law that keeps the planets in their orbits, and preserves the stars in their places, is shown to be identical with that which impels each particle of air and water in its ceaseless course around the globe.
There is still another interesting subject of speculation connected with the saltness of the ocean. We know that every river which flows through the land sweeps along with it to the sea a quantity of solid matter held in solution. This consists mainly of common salt, sulphate and carbonate of lime, soda, and similar substances. All this goes into the sea; but not a particle ever finds its way back to dry land again. The water taken up by evaporation is pure and fresh. It is borne in viewless channels through the atmosphere; is condensed, and falls to the earth as rain, or dew, or snow. It penetrates the strata of rocks charged with saline matter, which it dissolves and bears on with it to the sea again. Here it circulates through the ocean from the poles to the tropica, from the surface to the lowest depths, and from the bottom to the surface, until it is taken up again, and goes through the same great round. It is more than probable that every drop of water in the ocean has traveled these rounds many times since our present order of things was established.
Yet though from age to age so vast an amount of saline matter has been continually poured into the ocean, the composition of its waters has remained unchanged. The ocean is no more briny than it was five thousand years ago. What becomes of all this accumulation of matter? Where shall we look for the compensating agency to counteract this tendency to change?
This inquiry conducts us to another of those marvelous relations between the different kingdoms of nature, which show that all arc parts of one vast whole, so ordered that each portion is essential to the existence of every other.
While the rivers of the earth are thus pouring their accumulations of saline and caleareous matter into the ocean, innumerable myriads of beings, many of them so minute that we can discern them only by the microscope, arc engaged in elaborating this matter from the water, and building it up again beneath the waves into mountains and continents. The coral insects of the South Seas are evermore erecting their mounds and dykes, reaching in some instances farther down than plummet has ever sounded into the calm waters of the ocean, and stretching in an unbroken line for a thousand miles. Against these apparently frail barriers the long swell of the Pacific breaks with a force which would wear away a granite promontory; but the tiny architects seize upon the water, and by their own vital power extract from it, particle by particle, the substance from which they construct their impregnable walls. Every unmoving shell-fish aids in the work. The pearl oyster of Ceylon perhaps constructs its parti-colored shell from the lime swept by the tributaries of the Missouri from the canons of the Rocky Mountains, or worn away by the torrent that dashes down the precipice of Niagara. Every marine plant that grows upon the shore or the bottom of the ocean, or that floats in the great silent "Sargasso Sea" or Sea of Weeds, that occupies the mid-Atlantie, impeding the course of the few vessels that wander so far out of the ordinary routes of commerce, has also its appropriate function in abstracting from the water of the ocean the soda and other saline matter borne into it evermore.
The deep sea soundings so successfully executed by our naval officers, have thrown new light upon these exquisite systems of compensations by means of which nature is evermore "seeking by ceaseless change eternal rest." By an ingenious aparatus invented by Passed Midshipman Brooke, matter has been brought up from the bottom of the sea at a depth of more than two and a quarter miles. This matter brought up from such a depth, and far out at sea, beyond the influence of the ceaseless wash of rivers and other local causes, may be assumed to be a fair sample of the bottom of the entire ocean.
To the naked eye the matter thus brought up seemed mere clay or mud. But when it was placed under the microscope, the startling fact was brought to light that it was composed wholly of minute shells, the skeletons of animals so small that no unaided human eye could distinguish them. Not a particle of sand or gravel, not the remotest trace of mineral or inorganic matter was there. There was nothing but the relies of animal life. These animals could not have lived and died at the bottom of the sea,
where they would have been subjected to the enormous pressure of a column of water twelve thousand feet in height. They doubtless while alive inhabited .the upper waters; and when dead their bodies sank slowly down to the bottom in one continuous shower, like the snow-flakes that fall in a still winter day. For thousands of years —how many thousands no man knows.—this ceaseless shower has been pouring down. How thickly the ocean floor is paved with these remains, who shall dare to conjecture? But this much is certain that the remains of these animaleules indefinitely exceed in bulk those of larger animals. And all these remains have been abstracted from the waters of the ocean, where the materials of which they have been formed have been brought from the land by the ceaseless action of the waters originally raised from the surface of the ocean.
Thus it is that we are beginning to get glimpses of the harmonies and compensations of nature. Every element exists not for its own sake alone, but for that of every other. The air and the ocean, the dry land, all work together. The beat showered down upon the roasts of Brazil nourishes the vines and olives of Sicily; that generated in the Gulf of Mexico makes gieen the corn-fields of merry England, and the vineyards of France, and mitigates the terrors of an Iceland winter. The cold from the north pole, borne far below the surface of the ocean, and transferred to the Gulf of Mexico, transforms what would otherwise be an uninhabitablo desert into the garden of the earth; while that from around the south pole cools the waters that girdle the palmshaded islands of the tropical Pacific. The hidden fountains of the Mississippi and the St. Lawrence lie in the Indian Ocean. The dense foliage in the jungles of Hindostan and Farther Africa distills oxygen to vitalize the blood of the inhabitants of New York and London, who in tum give lorth the carbonic acid which adds to the stature of the date-trees by the cataracts of the Nile and the spice-groves of Ceylon. These are but a part of the functions that the atmesphere and the ocean perform in the wide economy of nature. When science has fathomed all of their manifold uses, we shall have made one more step toward the full significance of the term by which the ancient Greeks, poetical in their wisdom, designated collective nature: Kositos—" Beauty—Orderly Arrangement.
THE FIDDLER. V-,
SO my poem is damned, and immortal fame is not for me! I am nobody forever and ever. Intolerable fate!
Snatching my hat, I dashed down the criticism, and rushed out into Broadway, where enthusiastic throngs were crowding to a circus in a sidestreet near by, very recently started, and famous for a capital clown.
Presently my old friend Standard rather boisterously accosted me.
"Well met, Helmstone, my boy! Ah! what's the matter? Haven't been committing murdeH Ain't flying justice 1 You look wild!"
"You have seen it, then?" said I, of course referring to the criticism.
"Oh yes; I was there at the morning performance. Great clown, I assure you. But here comes Hauthoy. Hauthoy—Helmstone."
Without having time or inclination to resent so mortifying a mistake, I was instantly soothed as I gazed on the face of the new acquaintance so unceremoniously introduced. His person was short and full, with a juvenile, animated cast to it. His complexion rurally ruddy; his eye sincere, cheery, and gray. His hair alone betrayed that he was not an overgrown boy. From his hair I set him down as forty or more.
"Come, Standard," he gleefully cried to my friend, "are you not going to the circus? The clown is inimitable, they say. Come; Mr. Helmatone, too—come both; and circus over, we'll take a nice stew and punch at Taylor's."
The sterling content, good-humor, and extraordinary ruddy, sincero expression of this most singular new acquaintance acted upon me like magic. It seemed mere loyalty to human nature to accept an invitation from so unmistakably kind and honest a heart.
During the circus performance I kept my eye more on Hauthoy than on the celebrated clown. Hauthoy was the sight for me. Such genuine enjoyment as his struck me to the soul with a sense of the reality of the thing called happiness. The jokes of the clown he seemed to roll under his tongue as ripo magnum-bonums. Now the foot, now the hand, was employed to attest his grateful applause. At any hit more than ordinary, he turned upon Standard and me to see if his rare pleasure was shared. In a man of forty I saw a boy of twelve; and this too without the slightest abatement of my respect. Because all was so honest and natural, every expression and attitude so graceful with genuine good-nature, that the marvelous juvenility of Hauthoy assumed a sort of divine and immortal air, like that of some forever youthful god of Greece.
But much as I gazed upon Hauthoy, and much as I admired his air, yet that desperate mood in which I had first rushed from the house had not so entirely departed as not to molest me with momentary returns. But from these relapses I would rouse myself, and swiftly glance round the broad amphitheatre of eagerly interested and allapplauding human faces. Hark! claps, thumps, deafening huzzas; the vast assembly seemed frantic with acclamation; and what, mused I, has caused all this! Why, the clown only comically grinned with one of his extra grins.
Tnen I repeated in my mind that sublime passage in my poem, in which Cleothemes the Argive vindicates tho justice of the war. Ay, ay, thought I to myself, did I now leap into the ring there, and repeat that identical passage, nay, enact the whole tragic poem before them, would they applaud the poet as they applaud the clown? No! They would hoot me, and call me doting or mad. Then what does this prove? Your infatuation or their insensibility? Perhaps both; but indubitably the first. But why wail? Do
you seek admiration from the admirers of a buffoon? Call to mind the saying of tho Athenian^ who, when the people vociferously applauded in the forum, asked his friend in a whisper, what foolish thing had he said?
Again my eye swept the circus, and fell on the ruddy radiance of the countenance of Hauthoy. But its clear honest cheeriness disdained my disdain. My intolerant pride was rebuked. And yet Hauthoy dreamed not what magic reproof to a soul like mine sat on his laughing brow. At the very instant I felt the dart of the censure, his eye twinkled, his hand waved, his voice was lifted in jubilant delight at another joke of the inexhaustible clown.
Circus over, we went to Taylor's. Among crowds of others, we sat down to our stews and punches at one of the small marble tables. Hautboy sat opposite to me. Though greatly subdued from its former hilarity, his face still shone with gladness. But added to this was a quality not so prominent before; a certain serene expression of leisurely, deep good sense. Good sense and good humor in him joined hands. As the conversation proceeded between the brisk Standard and him—for I said little or nothing— I was more and more struck with the excellent judgment he evinced. In most of his remarks upon a variety of topies Hauthoy seemed intuitively to hit the exact line between enthusiasm and apathy. It was plain that while Hauthoy saw the world pretty much as it was, yet he did not theoretically espouse its bright side nor its dark side. Rejecting all solutions, he but aeknowled facts. What was sad in the world he did not superficially gainsay; what was glad in it he did not cynically slur; and all which was to him personally enjoyable, he gratefully took to his heart. It was plain, then—so it seemed at that moment, at least—that his extraordinary cheerfulness did not arise either from deficiency of feeling or thought.
Suddenly remembering arfengagement, he took up his hat, bowed pleasantly, and left us.
"Well, Helmstone," said Standard, inaudibly drumming on the slab, "what do you think of your new acquaintance!"
The two last words tingled with a peculiar and novel significance.
"New acquaintance indeed," echoed I. "Standard, I owe you a thousand thanks for introducing me to one of the most singular men I have ever seen. It needed the optical sight of such a man to believe in the possibility of his existence.
"You rather like him, then," said Standard, with ironical dryness.
"I hugely love and admire him, Standard. I wish I were Hauthoy."
"Ah? That's a pity now, There's only one Hauthoy in the world."
This last remark set me to pondering again, and somehow it revived my dark mood.
"His wonderful cheerfulness, I suppose," said I, sneering with spleen, "originates not less in a felicitous fortune than in a felicitous temper. His great good sense is apparent; but great good