designed by nature is, that of preventing accumulation of water in an almost enclosed sea; and that it effectually performs this office. these There is a design in everything of the creation. By diligence, it is permitted to man, in a certain extent, to discover for what purposes things were formed. In the instance of the Florida Stream, we may see clearly, from the particular disposition of the land and sea, (look at the chart or map,) that if such a conductor of the superfluous waters were absent, there would probably be great disarrangement in the partially enclosed waters of that part of the world, from the constancy of a perennial wind. Now, as it is impossible that there can be mal-administration in nature, if we subscribe to the use (it may have more than one) here assigned to this great stream, we cannot admit the higher level of the Gulf, because that admission would imply irregularity, or insufficiency of purpose in the plan of nature. There is not a single reason that I have ever heard brought forward to prove the fact entertained, or why such an anomaly should exist in nature; besides, as was said before, the assumption is opposed to the law of fluids. There is another opinion akin to this; I have forgotten the authority; but I give it here for the benefit of those who pin their faith" upon popular beliefs. Being an old "stager" in the locality, and one who ever kept his eyes open, I felt surprise on reading the passage, but thought it little less extravagant than the permanent higher level. It is to the effect that the rains and supplies from the rivers discharging into the Caribbean Sea, raise its level. The cebrated John Hunter's motto is a good one to be followed in these matters, "Think for yourself." So, I thought the Caribbean Sea rather a large area to be risen by rain or river water. I presumed to think that, in a clime where evaporation is so extensively powerful, that during the pluvial discharges in the two seasons, (not always regular in recurrence,) the sea remained at its usual natural level; and consequently, the great current was not affected by the waters which fell from the heavens. In tracing effects to their causes, the coincidence of circumstances, no doubt may be enlisted in argument; but it requires some caution, and much thought, in drawing conclusions from the apparent argument of facts, as it may turn out by close inspection, that a circumstance which at first seemed to be the cause of an effect, in reality has nothing to do with it. One observer being struck with the fact that the velocity of the Florida Stream is increased during, or immediately after the first rainy season of the Caribbean Sea, pronounces a supposed excess of water therein to be the cause of the activity of the current. But, I, as another observer, looking beyond the mere abstract fact, argue that such a cause is unequal to the production of such an effect, because there is an active counteracting principle which neutralizes it, and advance the more reasonable belief that the phenomenon arises from a change in the barometric pressure of the atmosphere. Perhaps, there are no more astonishing phenomena in the creation, than the remarkable variation of opinion, and the versatility of thought in man. It is to these wonderful differences that we are to trace in individuals among the millions of the same organized beings, the diversity of character and of action? They are cast in one general mould; they have eyes to see; hearts to feel, (according to belief); brains to summon up thoughts (according to sensation); and reason to guide the judgment. Whence arise those variations? Culture does not satisfactorily account for them, or assuredly men of equal capacity, attainment, and acquired knowledge, and experience, would never differ. One gazer pronounces The judgment is often guided by the eye. seas in the moon; another, no water! A current is seen to run always through a very narrow strait (the only one,) into a very extensive sea, elsewhere entirely encompassed by land. The conclusion is adopted that evaporation is so great within, as to keep this interior arm of the ocean at a lower level than the Atlantic outside, so that ships entering, sail down an inclined plane! Under-currents are unseen; therefore, in this instance they were unthought of. Well, let us go on the other tack, to look for the consistency of human opinion in this mental voyage of discovery. Another current is found to run, or, is supposed to run, into a less extensive, but still considerable, Mediterranean Sea, with a wider entrance; the other difference being that the one faces the west, and the other the east. Here, opinion is reversed; nothing is said of evaporation though the climate is partly tropical; but, the level of this sea is higher than the Atlantic, of which it is also a branch! Now, after these displays of human opinion, the reader, perhaps, will not wonder at the precedent queries. Be it remembered, that these opinions have been held by writers of talent, yet, I venture to say that presumptuous as it may appear, the common-sense of a practical seaman would pronounce either, a fallacy. "Knowledge is power"; and literary power, like that of station, may engender tyrrany. It is a blessing, however, that thought cannot be enslaved unwillingly; in that, we are all free, thanks (not to philosophers) to Providence. To prevent undue disarrangement, Nature is always on the alert. Water forced through an inlet, into an arm of the sea, where there is but one opening, runs out under the surface. I have convinced myself of this by trial. I consider it a general law of nature; for if it were not so, low coasts would be flooded where a perpetual current exists. As circumstances are in the Caribbean Sea, it appears to me that, the rain is balanced by evaporation, as far as regards the ocean, and the supply it receives from the land through the conducting troughs. I cannot compliment the advocates of the higher level on the lucidness of their philosophy, which appears to be a one-sided view, as they take no notice of the co-existence of this potent power, The same objection is pressing, whether applied to the permanent higher level said to be occasioned by the drifts of the Atlantic; or to the periodical disarrangement from rain, or whatever else may be surmised; unless the advocates can prove the insufficiency of evaporation for one of its designed purposes;-a point, I opine, rather beyond their power to accomplish. I do not pretend to subtility of research in physical phenomena, and therefore, it may be from sheer ignorance that I never could discover of what possible use a permanently higher level of one sea over another could be, although I am perfectly convinced that nothing is, which is not right, and for some useful purpose. I have been almost impudent enough to laugh outright, when I thought how funny it must be that the eastern Atlantic should persist against all reason and rhyme to keep a low position, joined as it is, north and south by a continuous ocean; or how ever it had learned mesmerism, so as to set the globules asleep! If the level of the Caribbean Sea, or the Gulf of Mexico, was disarranged at any time, some effect would be observed upon the shores of the continent and islands. Ask an inhabitant of Jamaica, and it is probable he would tell you that any visible effect on the water-line occurred only during hurricanes, or earthquakes. Enquire of a Mexican of Vera Cruz, and his answer would be, only during norths and other storms. The analogical reasoning used by the advocates to support the theory, of the effect of strong westerly winds blowing up the English Channel, is not a parallel case to that which they endeavour to uphold, the superior level of the Gulf of Mexico. There are no tides, or very slight ones in the latter; and if such was the case in the former, it is probable the water would flow off sufficiently quick to prevent accumulation in the Strait of Dover. But, the fact is that, the heaping up of the water there, does not rest solely on the effect of westerly gales, but also from two opposing tides meeting. There is no relative bearing in the two cases, and it is surprising that any writer of common intelligence should make the comparison. By way of convincing the sceptics, old writers on cosmography were wont to speak of the effect of the human breath on water in a wash-hand basin, to prove convincingly that from the constancy of the trade wind the great current was forced into the Gulf, and circulated round it. We may, too, be reminded that water in a tumbler may be made to assume a convex shape without overflowing. I have tried it often; but we must recollect the fluid is stationary. In a river, and I dare say, in the narrow part of sea channels, the middle of the stream in a tides'-way is slightly convex. In rivers, this occurs only with the ebb. In such a huge basin, however, as the Sea of Mexico, remarkable for the violence of its winds, and the volubility of its waves, it is highly probable such a phenomenon never happens. An accumulation of water in the Sea of Mexico we may reasonably believe could not occur without a visible effect, which would not be lost on the minds of the witnesses; and would be particularly felt on the borders of the Florida Strait, which according to the theory is on a lower level. It should follow, as clearly as any effect follows a known cause, if this inclined plane existed, that there would be a constant flow of the accumulated water towards the entrance at the Dry Tortugas; (look at the chart,) for as the fluid is said to be urged in in some part of the opening, it must either inundate the land, or run out in another part; and this as constantly. There is not, however, any such effect perceived. What is it that writers mean when they state that the greatest velo. city of the great stream is coincident with the greatest disarrangement of the Caribbean Sea and Gulf? Accumulation of water I conclude is meant. It so happens that, at the season when the current is reported as being briskest, the north-east trade wind is less active, and calm prevalent; the disarrangement therefore, if it exists, must be due to something else to the rains? I have expressed already my conclusions on that point. At this season, evaporation is active over the entire area of the Gulf, and we find that tracts of arenaceous matter line many parts of the seaface of the land. These masses of sand are as absorbent as a sponge. Under-currents, are no less active, and hence we may affirm that, vigilance of nature is constantly exerted to prevent disarrangement, and preserve the level of the sea. If an accumulation of water took place, it would show itself otherwise than in the increased velocity of the great current; the low tracts would be inundated. This, perhaps, may be fairly insisted upon, as the consequence of temporary accumulation may be seen when stormy and continued easterly winds blow in the Florida Channel, especially in the action of those winds during the transit of a hurricane across the direction of its current; the water is pressed to leeward, and the cays are covered. The higher level, and the periodical disarrangement of the Caribbean Sea, and Gulf of Mexico are assumptions drawn to account for the existence, and the increased velocity of the stream which runs with such magical effect through the Florida Channel. To me it appears that aqueous local influences have little to do in either. Such a current requires a stronger moving power to originate, to perpetuate, or to vary its velocity, than any superfluity of water which the winds, the rains, and the rivers combined could possibly give to it; bearing in mind the counteracting effects of evaporation, and under-currents. Whatever surplus water the drifts may press towards the "sack," is carried off by the great stream. Is it not equal to that? It has sometimes been called the "Mysterious Ocean River." To those who advocate the trade-wind source, or to others who uphold the mechanical effect of the earth's rotary motion theory, it appears anything but mysterious; yet, neither are prepared to tell us where it begins, or where it ends. There is not a seaman practically acquainted with the two Seas alluded to, I feel assured, that would for a moment believe the drift occasioned by the trade-wind equal to the production of such a wonderful current, and the extraordinary velocity it attains, allowing for the effect of its compressed body in the Strait. As to the effect of the rotary force and its supposed friction, we may safely apply the words in the description of the orbitual motion:-"This NO. 1.-VOL. XIX. E tremendous power is silent and ineffective. The earth rolls on; but, its motion never hurts the most delicate flower, or the most tiny insect, or interferes with the operations which are going on in the remoter and rarer portions of the atmosphere, where, probably, the millioneth part of a grain in weight would affect the whole operations." Whatever wiser heads may do, my intelligence can discover no reason why precisely the same may not be said of the diurnal motion. The theories of the Florida, or Gulf Stream have been for a long time stationary, in a sort of atrophy as it were, perhaps from neglect. Many pretty things have been written about it, even by men of talent; but in fact, what we do really know about it would seem to amount to no more than that it is a great current, variable in its rate, and has always been, since the settlements of the west, a "famous lift" to the homeward bound; of high temperature; and that, the Genii which preside over its steamlike atmosphere often show their choleric character. All the rest with reference to intrinsic value, may very compactly be stowed away in the socket of a musquito's eye! As to the origin of this mighty current; why Gulf Stream? Gull, would be more appropriate, as it abounds in the Larus tribe. If the government would direct one or two ships of each station to trace it back, it is probable its commencement would be found at a very remote distance from its outlet near the Bahamas. CURRENTS OF THE OCEAN. Ship Brocklebank, at Sea, 10th Nov., 1849. SIR.-I send you the accompanying account of Currents, copied from my Journals; you are aware that seamen have no better means of ascertaining the direction and velocity of Currents, than by comparing a carefully kept dead-reckoning with observations. It was by such means the accompanying results were obtained, omitting all differences under ten miles. I am, &c., To the Editor N.M. HENRY PONSONBY. Barque Esk from Singapore. Date. Lat. S. Lon. E. Direction and Velocity. Winds. S.S.W. to S.E. West 13 miles |