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to huge barges, including the gay 'flower boats.' | British ship, Little Belt, which was disLoud shouting from the fleet announced the masted off Nova Scotia in 1809, found its appearance of the flood, which seemed like a way into the Basque Roads after a sail of glistening white cable stretched athwart the eighteen months. Two Indian corpses river at his mouth, as far down as the eye could which made their appearance at the reach. Its noise, compared by Chinese poets to that of thunder, speedily drowned that of Azores in the fifteenth century, hinted at the boatmen; and as it advanced with prodi- a strange land beyond the flood; and from gious velocity-at the rate, I should judge, of this dead man's voyage Columbus drew twenty-five miles an hour -it assumed the decided auguries in favor of the unvailed appearance of an alabaster wall, or rather of a world in the west. But in tracing curcataract four or five miles across, and about rents we can not always calculate upon thirty feet high, moving bodily onward. Soon it reached the advanced guard of the immense drifting bodies, nor can we afford to disassemblage of vessels awaiting its approach. mast vessels for the purpose, any more Knowing that the bore of the Hooghly, which than the Chinese would have found it scarcely deserved mention in connection with the prudent to burn a house every time they one before me, invariably overturned boats which wished to indulge in the luxury of roastwere not skillfully managed, I could not but pig. A cheaper expedient may be adoptfeel apprehension for the lives of the floating ed. Throw overboard a bottle containing multitude. As a foaming wall of water dashed impetuously onward they were silenced, all a scroll on which is recorded the date and being intently occupied in keeping their prows whereabouts of your vessel. If this simtowards the wave which threatened to sub-ple little exploring apparatus should fall merge every thing afloat; but they all vaulted, as it were, to the summit with perfect safety. The spectacle was of greatest interest when the cagre had passed about one half way among the craft. On one side they were quietly reposing on the surface of the unruffled stream, while those on the nether portion were pitching and heaving in tumultuous confusion on the flood; others were scaling, with the agility of salmon, the formidable cascade. This grand and exciting scene was but of a moment's duration; it passed up the river in an instant, but from this point with gradually diminishing force, size, and velocity, until it ceased to be perceptible, which Chinese accounts represent to be eighty miles distant from the city."

But if the tidal wave on the high seas is a kind of optical hoax, so far as the actual translation of the waters is concerned, there are great ocean rivers which constantly convey the fluid of one hemisphere to another, and from the cold poles to the glowing Line. Nothing can be more surprising than to reflect that the liquid expanses of our globe are traversed by streams which flow as regularly as the Amazon or Mississippi on land. Channels have been dug out for them apparently, and for thousands of miles they pursue their course between walls of water as if they were treading rocky passes or rolling over granite beds. Some currents are simply periodical, others are variable; but the most important ones are constant, and, if followed, will conduct the navigator along the same settled route as surely as the Rhine will carry a tourist past Bonn and Cologne who starts from Coblentz on his return to the sea. The bowsprit of a

into intelligent hands, it will serve the object as effectually as a broken-down seventy-four. Let it be flung into the sea off the coast of Africa, for example, and if picked up at Jamaica, or found quietly coming to anchor in some English harbor, it will tell its own tale almost as forcibly as if it had kept a regular log. Admiral Beechy has published a chart containing the results of more than a hundred bottle-voyages, and from his interesting document it would appear that some of these fragile mariners had made the circuit of the Atlantic, and then, like Tony Lumpkin's victims, had resumed their route in the vast "circumbendibus." Much, indeed, yet remains to be done in the mapping out of these great ocean streams; but the course of many has been ascertained with sufficient certainty to entitle us to regard them as fixed and well-established highways across the deep.

By far the most influential of these currents is the famous Gulf Stream. Little as it may be appreciated by Englishmen in general, every inhabitant of this country has a greater interest in its flow than he has in the Thames or Tyne. It takes its rise in the Gulf of Mexico, though it may be regarded as a continuation of the mighty equatorial current which sets out from the western coast of Africa, and, after a run of four thousand miles, enters the Caribbean Sea. Sucking up the sun's rays as it advances, and storing away the warmth for future use, it passes into that magnificent indentation in the Mexican coast which

serves as a caldron; for there its waters are raised to the high temperature of 86.° It then sweeps through the Pass of Florida-its heat being 9° more than the ocean can claim by virtue of its latitude and skirts the shores of North-America, until it takes that remarkable bend off Nova Scotia and Newfoundland which throws its waters across towards the coast of Europe. One branch curves downwards and flits past the Azores to the south: the other glides northward in the direction of the British Isles and the Polar Sea. This splendid stream is supposed to be equal in volume to three thousand Mississippis. Its length, reckoning from its Mexican head to the Azores, is upwards of three thousand miles. Its velocity in the Gulf of Florida is about seventy-eight miles a day, but its pace dwindles down to a sober flow of ten before it reaches the Azores. Its average performance is about thirty-eight miles in the four-andtwenty hours. There are many peculiarities attached to this noble current. The color of its waters is an indigo-blue as far as the coast of the Carolinas. Its banks, especially the left, are generally well defined; so that the voyager knows when he dips into its flood, the edge being frequently made manifest by the ripplings which mark the line of division as well as by other visible traits. "Often one half of the vessel may be perceived floating in the Gulf Stream water while the other half is in common water of the sea: so sharp is the line, and such the want of affinity between those waters, and such the reluctance, so to speak, on the part of those of the Gulf Stream to mingle with the common water of the sea." It would appear, too, that this current acttually runs up hill, for the thermometer shows that the under part, in flowing from Cape Hatteras to the Capes of Virginia, makes an ascent of six hundred feet, being a gradient of five or six feet to the mile. It is noticeable, also, that the surface of this ocean river slopes from the center or axis to the sides; in other words, it resembles the roof of a house, though of course much gentler in its declivity; for if a boat is abandoned, it will drift to the right or left, according to its position with respect to the ridge. Partly for the same reason all planks, loose seaweeds, and other detached articles which may embark on the stream, will eventually slide down towards the edge of the current. Hence

has been formed that remarkable expanse in the midst of the Atlantic called the Sargasso Sea. This is a continent of weeds, (fucus natans,) thickly interwoven, and capable of offering considerable resistance to a passing vessel. How great were the fears it excited amongst the companions of Columbus, on their first trembling voyage to America, is well known. Collected here as in a prodigious eddy, this floating mass has occupied the same mean position-for it is subject to a kind of rise and fall in latitude-since the time of its discovery; and here, too, it will doubtless remain so long as the equatorial current and Gulf Stream continue to execute their stupendous rounds.

Taking, however, the diurnal motion of the earth into account, it ought to follow that, as an atom of air, when flowing from the pole to the equator, should drift, or seem to drift to the west, because of its tardier momentum, so any article which may enter the stream, when impressed with an equatorial velocity, ought to incline towards the eastern bank. And such appears to be the case, as far as the sloping character of the surface will allow. Trees torn up from their homes are plentiful on the European side of the current, but comparatively rare on the American. Just so, in the Mississippi, floating timber slides off to the western shore of the river if its voyage is sufficiently long to permit the rotation of the earth to tell upon its movements. For the same reason, too, the Gulf Stream itself should exhibit a strong European tendency, and to this cause we think may be partly ascribed the fact that, when the original velocity which enables it to cleave its way so readily through the waters has abated, it overshoots its banks and spreads out into a broad surface flow, as if to diffuse its genial warmth over the largest possible area.

For here we discover the great function of the stream. It is the bearer of tropical heat. A river of molten metal could not speak its purpose more explicitly. It sets out with a temperature of 86°. It cools but gradually as it advances, losing not more than 13° or 14° during its progress. So superior is its charge of caloric that the thermometer at once detects the difference between its fervid waters and the ocean around. The voyager feels that he is entering a warmer climate when he sails into the atmosphere

which overlies its route.

Imagine the change which would be experienced by Sir Philip Brooke when the air happened to be at the freezing-point on each side, whilst the current itself was nearly fifty degrees in excess! It is obvious that this incessant transport of caloric to the north must have its effect upon our chilly climes. Even where the heated waters can not pass, the winds which sweep over the sea from the south-west must be warmed by contact with the broad diffusive stream. Maury asserts that the surplus heat brought into the region of Newfoundland each day would be sufficient, were it suddenly let loose, "to make the column of superincumbent atmosphere hotter than melted iron." Or, putting the question on a larger basis, he says: "A simple calculation will show that the quantity of heat discharged over the Atlantic from the waters of the Gulf Stream in a winter's day would be sufficient to raise the whole column of atmosphere that rests upon France and the British Islands from the freezing-point to summer-heat." Could any thing be more palpable than the advantages of such a glowing river? If caloric could be stored up in casks, and whole fleets employed in conveying them from the tropics to the northern shores of Europe, some addressed to Britain, some to Norway, some to Spitzbergen, the marks of benevolent design could not be more vividly expressed. In point of latitude England corresponds with Labrador. But we know that the latter region is one where the climate is exceedingly harsh, where the winter is painfully protracted, where the vegetation is feeble and haggard, where the animals are heavily furred to keep them warm, and where the inhabitants are low-typed and extremely unlikely to figure brilliantly in the history of the world. Had we been left in the same lurch, and compelled to subsist on our geographical allowance of caloric alone, England would have been a frost-bitten realm, where fairs might have been held on the Thames every winter, and where boys might have snowballed each other for half the year. Stop the Gulf Stream to-morrow, divert it in some other direction, so that its summer-laden waters should never approach the European shores-and then John Bull would soon become a national pauper; and that oft-anticipated catastrophe, the ruin of the Constitution, would assuredly ensue.

To this stream there is a striking counterpart, so far as it extends, on the corresponding shores of the Pacific. Part of the great equatorial current, after sweeping across that ocean, presses into the seas of China and Japan, where it is deflected like the sister river on the east of the American continent. Thus repelled, it glides over to the opposite coast, and bathes it with its heated wave. Though somewhat indistinctly defined, there can be no doubt that such is the fact, for Asiatic driftwood has been found on the Aleutian isles, and crippled Japanese junks, as was the case with one in 1831, have been borne along to the mouth of the river Columbia. Now, has England no interest in this remote river of the deep? On the contrary, one of her largest provinces is in a great measure dependent upon it for its thermal welfare. As if Providence had expressly adjusted these marine streams for the benefit of our Empire, we find that the recently-established colony of British Columbia is provided with a hot-water apparatus which insures it a much more generous climate than its geographical position would warrant. The temperature of this new state is almost identical with our own. In Great Britain we flatter ourselves that we grow one of the finest races on the globe, and to our gentle skies-neither too hot nor too cold, neither enervating our frames by the excessive heat of the south, nor limiting our exertions and crippling our commerce by the frosts of the north-we ascribe, and justly ascribe, the practical superiority of our human ware. Is it not a remarkable circumstance, therefore, that this promising province, with its gold, its coal, and its other splendid mineral endowments-a province which may become the seat of an empire reared by British brawn and animated by British brain-should owe its climatic advantages to a silent river of heat which comes from afar, and discharges its stores of caloric upon the region, as if to protect it from the blighting tyranny of frost?

One great object of currents therefore is plain. It is their duty to equalize as far as may be the climates of the globe, and moderate the extremes of heat and cold. Were not some such precaution adopted, the gathering ice of the poles would ultimately render a large portion of the globe intolerable from excessive frost, whilst the concentrated heat of the tropics might convert them into sultry wastes, some

breezes, upon whose faithful flow he can | depend for more than five months together-breezes which will kindly bear his bark in one direction, and carry it back as well-to those Saharas which seem such scars and blemishes on the face of our planet."He that made both sea and land," says Bishop Hall, "causeth both of them to conspire to the opportunities of doing good."

Still what of the depths of the ocean? To know something of the surface is by no means sufficient. Naturally we feel as curious to probe those silent abysses and to investigate the secrets of Neptune's halls as Bluebeard's wife did to pry into the mysteries of the sealed chamber. Unfortunately it is not easy to gratify this laudable longing. The lively and ingenious Bishop Wilkins-he who maintained the possibility of constructing a flying chariot which would transport any enterprising gentleman to the moon-was also of opinion that an "ark" could be contrived whereby the bed of the sea might be explored, and various interesting discoveries effected not only of sunken treasures but of remarkable physical phenomena. Upon this enchanting topic his lordship is delightfully loquacious; and after discussing the means by which the submarine vessel is to be moved, its fouled atmosphere rectified, its passengers received or discharged, he asserts that "whole colonies may thus inhabit," living constantly at the bottom of the sea, printing their observations on the spot, and even bringing up families, whose surprise, on ascending for the first time to survey the glories of this upper world, is joyously depicted. 'Tis a grievous pity that the project of this charming visionary can not be realized; for who would not exult to learn that arks manned by crews of savans were groping their way along the floors of the Atlantic and Pacific in all directions, and that sooner or later the geography of the drowned portions of the globe would be taught in our schools as familiarly at least as that of Africa or Japan? But, alas! we know well that the pressure of the water upon any manageable vessel would be too prodigious to admit of any extensive descent, and that the difficulty of procuring fresh air would forbid any prolonged sojourn beneath the surges of the ocean.

Perhaps, however, the reader may be dispose to imagine that nothing could be

easier than to ascertain the depth of the sea at any particular spot. Heave out the lead, give it as much rope or line as it requires, and when it ceases to run from the real, you have gauged the abyss to a a yard. The task, however, is more difficult than it looks. The sea is as coy in revealing its depths as a lady in disclosing her age. In the profounder probings of the ocean how are you to know when the weight really touches the bottom? Some persons would tell us that at a certain distance from the surface the resistance must become so great that the lead will cease to sink, and that even parted anchors and iron cables must remain in suspension. This fancy rests upon the assumption that water is a compressible fluid; for not until its particles were crushed into such small compass that a cubic inch of the liquid should equal a cubic inch of the metal in gravity, could the latter be induced to float. Practically speaking, however, water may be regarded as an obstinate and irreducible thing, for Oersted ascertained that under the pressure of each additional atmosphere it shrunk to the extent of forty-six millionths of its bulk only. But still in attempting to fathom Neptune's domains, currents may carry out the line, and you may imagine that the plummet is plowing its way through the waters long after it has reached the bed of the sea. In 1852, Lieut. Parker ran out mile after mile of cord while exploring the ocean off the coast of SouthAmerica. Deep seemed to call unto deep, for here no bottom could be found, though ten miles of line were delivered. But on subsequent trials it was discovered that the true depth was not more than three miles, and the discrepancy could only be explained by referring it to the disturbing action of currents, which may sweep away the cord, or gather it into loops if they happen to flow in contrary directions.

Amongst the various contrivances which have been proposed or adopted for ascertaining when the bed of the sea is really reached, some are intended to tell their own tale de profundis, either by ringing bells, exploding shells, giving electromagnetic signals, working clock-machinery, or registering the pressure to which a column of air is exposed. None of these, however, have served their purpose effectually, and some have egregiously failed. In the navy of the United States a very

Maury was enabled to predict the course | period, and from the north-west during and position of a steam-vessel, the San the latter. Francisco, which was disabled in a storm in the year 1853, whilst conveying a regiment of United States troops to California. Great alarm being excited by the arrival of barks which had seen her in this crippled condition without being able to render any assistance themselves, searching vessels were promptly dispatched. But where were they to look? Science instantly mapped out the limits within which the ship would be likely to drift, and even indicated the very quarter where she would most probably be found. The exploring vessels took up the trail of the storm, and pursued the track which had been prescribed; but before they could reach the spot where the steamer was expected, relief had arrived. Had they not been thus anticipated, their instructions would have carried them within sight of the wreck. Strange to say, the Kilby, one of the vessels which accidentally contributed to the rescue, parted company with the transport ship in the night, and could neither find her in the morning nor tell in what direction to look; yet, hundreds of miles away, a philosopher sitting quietly in the National Observatory at Washington, could lay his finger on the chart, and guide the explorers to the locus of the shattered ship.

Still more striking, perhaps, than the influence of heated water in the production of atmospheric disturbances, is the influence of heated land. There are the monsoons, for example. These are tropical winds which, instead of keeping up the character of the family for fickleness, blow steadily in one direction for about five months, and then blow as steadily in a different direction for about five months more. Each change occupies about a month, and is a very fussy transaction, being accompanied by blinding lightnings and deafening thunders, by rains which render the atmosphere opaque, and blasts which lift the surf and sometimes carry fishes into the interior. Subject to the gradual shiftings of direction which occur at these transition periods, and neglecting the consideration of certain local limitations, it may be said generally that north of the equator the wind blows from the south-west between April and October, and from the north-east between October and April. South of the Line it comes from the south-east during the former

Now, what occasions these monsoons? A voyager in the Indian Ocean may little suspect that the cradle of the breeze by which his vessel is impelled lies far away in the interior of Asia. Yet such is supposed to be the case. The vast naked plains and the great desert tracts of the continent, when heated by the sun's vertical rays, must rarefy the atmosphere overhead, and produce a draught as if a furnace where in play. To feed this partial vacuum, air will be dragged in from any quarter where it can be procured. Since, then, these disturbing districts lie in the rear of the north-east trades, it is presumed that the stream which feeds them will be arrested, and that the trades themselves will be drawn back and pulled towards the affected spot. Further, the balance between the north and south trades being broken-for the meeting of these two produces that belt of equatorial calms which is elegantly known as the Doldrums or Horse latitudes-the southern trade, on finding no resistance, will pour over the Line into the northern hemisphere. But, in doing so, it will yield to the same distant influences which have troubled its brother trade, and at the same time will undergo deflection to the east, because it is now impregnated with the earth's equatorial velocity. The result (difficult to express without diagrams) will be the production of a south-west wind, such as actually blows north of the equator from April to October. It follows, also, that if these monsoons are due to the sun's influence as described, they should coïncide in their proceedings with the position of this luminary. And such is the case. When the south-west monsoon is in force, the deserts of Cobi and the peninsula of Hindoston are blazing under his directest beams; when the north-east breeze is in constant play, it is a sign that his presence has been transferred to the southern hemisphere.

Applying the same principles to the monsoons of Africa, the Gulf of Mexico, and Central America, we may fairly conclude that these phenomena are occasioned by the deflection of the trade-winds in consequence of the overheating of distant plains and deserts. sandy wastes thus become important agents in the ocean economy, and the mariner owes the steady, serviceable

Even great

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