« AnteriorContinuar »
PAPER ON THE GULF STREAM AND CURRENTS OF THE SEA.
READ BEFORE THE NATIONAL INSTITUTE, APRIL 2nd, 1844.
(Copyright secured according to Law.)
BY M. F. MAURY, LT. U. S. N.
I am invited, in the name of the National Insti- | and set on foot a plan for multiplying observations tute, to address this meeting on the Gulf Stream and extending our information upon these inteand other currents of the sea. This is an impor-resting phenomena. A subject of vast importance tant subject, important to civilized man in the in the business of commerce and navigation, the every-day business of life, and vitally important currents of the ocean seem to me to be altogether to all who use the sea : whatever relates to it, worthy the attention of this society--a series of therefore, can not fail to be highly interesting and well conducted observations upon them would be important to a nation so renowned as this is for its in perfect unison with the great objects of usefulmaritime pursuits.
ness for which it was created and now exists, and Upon a correct knowledge of the force and set for which its distinguished members and guests of currents on the Ocean, often depends not only have been invited, and are here assembled from all the safety of vessel and cargo, but the lives of all parts of the conntry. on board; and, owing to the want of this know- Before such an assemblage of mind and intelliledge, hundreds of vessels, thousands of persons, gence, it is necessary only to mention the meagre and millions of property are annually cast away or state of our information even with regard to that lost at sea.
great anomaly of the Ocean, the Gulf Stream, and I do not intend to occupy the time of members there will be-there can be but one mind as to the with a recapitulation here of what we do know importance of making further observations, and of with regard to Ocean currents ; that indeed might multiplying facts with regard to it. In simply resoon be told; for we know little or nothing of minding the society, that all we know of this wonthem, except that they are to be met with here and derful phenomenon is contained chiefly in what there at sea, many of them sometimes going one Doctor Franklin said of it more than 50 years ago, way and sometimes another; and that the waters that his facts were collected by chance as it were, of some of them are colder and of others warmer and his observations made with but few of the fathan the seas in which they are found. That we cilities which navigators now have, I feel that should have a better knowledge of them, and of enough and all has been done that is necessary to the laws which govern them is not only an impor- be done, in order to impress the Institute with the tant matter to those who follow the sea, or make importance of further observations upon it. ventores abroad, but it is also a matter of exceed- Were it the Institute only that is concerned in ing interest to all those whose enlarged philan- the matter, I would not say a word more on the thropy, or ennobling sentiments prompt in them a subject, believing that all that I can say will add desire to diffuse knowledge among their fellows, nothing of force to the appeal contained in the or in any manner to benefit the human race. The mere announcement of the fact just stated. But mere fact that this meeting is held at all, is evidence we live in a utilitarian age; we belong to a comample and complete, that it is composed altogether munity of people eminently utilitarian in their of such. I therefore submit it is a question for habits of thought and motives of action ; and, when the consideration of this meeting, whether it be they are called upon to coöperate, as they must be not competent for the National Institute to devise in all great measures of usefulness undertaken by
an Institution so emipeptly national in its associa- | An examination by skilful engineers is now being tions and its character' as this is, the question "cui made as to the practicability of re-opening this bono,” on their part, must first be met, at least to inlet. In their eyes at least a correct knowledge some extent, before the requisite degree of coöpe- of the effects and tendency of this current would ration can be obtained.
be of great value. Distrustful of my ability to meet on the present This circumstance explains better than volumes occasion, this question as it can be met, and ought of disquisition could do, the “cui bono" of collecthere to be met, I would cease from the attempt in ing and recording every fact whatever that obserhopeless despair, were it not for the respect which vation may give us with regard to the currents on I entertain for the discernment of the distinguished our coast. That they are effecting important members of the Committee who have selected me changes along the sea board, the singular chain of for the task.
| long and narrow islands that curtain the coast from As a people, we are disposed to do but little for Albemarle Sound to the reefs of Florida, gives science out of mere zeal for the cause. We are ample evidence. These and the shoals which not apt to be prominent in any of its walks, unless endanger navigation off the Capes of Carolina, we can perceive to our oft repeated "cui bono,” owe their existence entirely to currents, or upfrequent answers, like finger boards by the way side, lift. The soundings and form of the Hatteras to guide and to cheer us on. But when our way and other shoals clearly indicate that they are is thus made clear, it redounds not a little to the caused by a current from the North. A comparicredit of the American people that they are fore- son of present charts with Jeffry's atlas published most in pursuit.
in 1775, shows not only that these shoals are inOf this, the science of Geology affords a stri- creasing, but that the chain of islands alluded to king example. Chemistry and Astronomy in the is in process of gradual formation. Currituck and Old World struggled for centuries in sickly in- Roanoke inlets which are now sand bars, once fancy; but, on this side of the water, modern Ge- were navigable. Occracoke inlet had then 17 feet ology, like the Goddess of old, leaped at a bound, of water, it now has 8. Besides these there were fullgrown and panoplied into being. Immediately between Beaufort, North Carolina and Charleston practical in its character and useful in its results, in South Carolina, 25 or 30 others, many of them the people were eager in the pursuit of its princi- then navigable, and most of them now closed and ples. And for the honor of popular Institutions appearing only as dry land. be it said, the States of Republican America have Whence comes the sand that forms these islands! done more for the science of Geology than all the Separated from the main land by standing pools of governments of all the world besides. They fos- water moved only by the tides from the Ocean, it tered it with a care and pursued it with an energy can not be brought from the shore. It can only be that no other department of science ever before upheaved with the general elevation of the coast received at the hands of a nation. But 'twas not by geological agencies, or it is cast up from the for the mere love of science that geological inves- bottom of the Ocean by the Gulf Stream and the tigations were thus encouraged among us. It was waves, or brought down from the North by the because its ends were adapted to our utilitarian current on the coast. Investigation might setile ideas, and in themselves promptly answered the the question. great question of utility now to be met.
Linked thus with other geological agents, the Our researches in this field have revealed to us currents of the sea can not fail to present themthe fact, that the Ocean and its currents have been selves to the mind of the Geologist, as important and no doubt still are important and active Geolo- and interesting subjects for investigation. How gical agents.
Of this truth, all the tide water much more so are they in the eyes of the Naviga“ country to the South and much of that to the North tor ; with him, the source of this coast current is of us, is a present witness.
a matter of conjecture, and its cause a mystery. To say what agency the Gulf Stream and other And as to its strength, its fluctuations and the laws corrents now known to us, had in this formation, which govern them, his nautical books are all but would carry as too far into the regions of specula- silent. Nor has the history of navigation recorded tion for our present purpose. But thus much we the first series of systematic observations upon it. may venture : that between us and the Gulf Stream Proceeding furthur into the Atlantic, we find a there is a current of cold water running towards vast stream of warm water running counter to this. the South with sufficient strength to produce im- It is the Gulf Stream bound from the Straits of portant changes along the coast. Two hundred Florida to the Banks of Newfoundland, and thence and fifty years ago, Sir Francis Drake with his to the shores of Europe. What its breadth or its fleet entered Albemarle Sound through Roanoke depth may be, we know not. We are told indeed Inlet, which is now a sand bank above the reach that even at the same place it runs sometimes at of the highest tides. Only seventy years ago, it the rate of two knots the hour, sometimes at fire
, was navigable by vessels drawing 12 feet of water. and we know that it may always be found within
certain broad limits, varying in this too at the same Therefore the Gulf Stream offers a field of inplace, from 140 to 340 miles. With this our know- vestigation peculiarly American, and we, the Ameledge of it ends ; though more accurate informa- ricans, are in duty, as we are in honor, bound to tion as to it and its offsets would many a time have show ourselves curious and diligent in whatever saved the mariner from disaster, and his vessel there may be about it, of undiscovered mystery, from shipwreck, and even now, would add not a little or of philosophic interest to navigation, or other to the speedy and safe navigation of the Atlantic. branches of science.
Though Navigators had been in the habit of In Dr. Franklin's time, the navigator guessed crossing and recrossing the stream, almost daily, as much as he calculated the place of his ship-vesfor the space of near 300 years, its existence even sels from Europe to Boston frequently made New was not generally known among them, until after York, and thought the land-fall by no means bad. Dr. Franklin discovered the warmth of its waters, Chronometers, now so accurate, were then an exabout 70 years ago. And to this day, the infor- periment. The Nautical Ephemeris itself was mation which he gave us, constitutes the basis, I faulty, and gave errors of thirty miles in the lonhad almost said the sum and substance of all we gitude. The instruments of navigation erred by know about it.
degrees quite as much as they now do by minutes ; When he was in London, in 1770, he happened for the rude“ cross staff" and " back staff,” the to be consulted as to a memorial which the Board sea ring” and “mariner's bow," had not yet given of Customs at Boston sent to the Lords of the place to the nicer sextant and circle of reflection Treasury, stating that the Falmouth packets were of the present day. Instances are numerous of vesgenerally a fortnight longer to New York than sels navigating the Atlantic in those times being 6°, common traders were from London to Providence, go and even 10° of longitude out of their reckoning R. I. They therefore asked that the Falmouth in as many days from port. Our means therefore of packets might be sent to Providence instead of to properly conducting a system of observations upon New York. This appeared strange to the doctor, the currents of the sea, and for following up the infor London was much farther than Falmouth, and vestigations of Franklin, are much more ample and from Falmouth the routes were the same, and the complete than they have ever been with navigators difference should have been the other way. He before. Therefore what society so appropriate as however consulted a Nantucket whaler who chanced this, the National Institute of his country—what time to be in London also; the fisherman explained to him more fit.-what occasion more suitable than the that the difference arose from the circumstance that present for maturing a plan of operations, and for the Rhode Island Captains were acquainted with setting on foot a system of observations upon the the Gulf Stream, while those of the English pack-Gulf Stream and its kindred phenomena of the sea ? ets were not. The latter kept in it and were set
As commendable in some respects as is that back 60 or 70 miles a day while the former avoid- utilitarian spirit among us which is so apt to try ed it altogether. He had been made acquainted our undertakings with “cui bono ?" it is not wise with it by the whales which were found on either always to start this question; for, the apparently side of it, but never in it. At the request of the trifling facts by which the laws of nature are often doctor he then traced on a chart, the course of revealed to the philosopher and are made subserthis stream from the Straits of Florida. The vient to our purpose, will not, at all times, brook doctor bad it engraved at Tower Hill and sent the inquiry. copies of it to the Falmouth Captains, who paid no When the Italian Philosopher commenced his attention to it. The course of the Gulf Stream, experiments, what utilitarian saw in the fact elias laid down by that fisherman from his general cited from the legs of a dead frog, the important conrecollection of it, is retained on our charts at the sequences to which it has led us, and to this day present day, almost without an alteration.* continues to lead us ? The principles deduced from
If within the domains of Philosophy, there can his simple discovery, after having led to many imbe such a thing as a proprietary field of investiga- portant and valuable results, are now, at the end of tion, this phenomenon of a river in the Ocean is half a century, being applied for our purposes in one-American in its source and origin, it is found such a manner, that words spoken in yonder capiin the waters of America, and closely concerns tol, may be conveyed to other cities with the speed its navigating interests; first traced out by the of lightning, and caught up there as they fall here fishermen of New England, it attracted the atten- from the lips of the speaker. tion of the great American philosopher: he deter- When our own Franklin flew his kite in the mined its most remarkable characteristic, and left storm, who would have thought that the inkling it to his countrymen as a field to be re-occupied which he then caught as to a law of nature would by them at some future day, and with a like spirit enable us to turn aside the artillery of heaven? of philosophical research.
Or when, at another time, he dipped his ther
mometer into the sea, how could the most keen* Page 485 and plate XII., Vol. 6th Spark's Franklin. sighted utilitarian have perceived that the fact thus discovered would shorten the average passage across Stream, is matter of conjecture. Before their temthe Atlantic, at least one third; would bring the old perature was known, vessels thus distressed, knew world and the new nearer together by many days, of no place of refuge short of the West Indies; and would wonderfully improve and benefit Navi- and the newspapers of that day,-Franklin's Penngation ?
sylvania Gazette among them,-inform us that it To the philosopher, every newly discovered fact, was no uncommon occurrence for vessels, bound in physics, however trifling to others it may seem, for the Capes of the Delaware in winter, to be is a gem. Our knowledge of nature and her laws blown off and to go to the West Indies, and there is but a number of such facts, brought nigh and wait for the return of spring before they would placed side by side. As they accumulate, they attempt another approach to this part of the reflect light upon each other, and each generation coast. becomes wiser and wiser, for every such fact thus Accordingly, Dr. Franklin's discovery of the gathered is but another clue placed in our hands, Gulf Stream temperature was looked upon as one which, if carefully followed up, will lead us further of great importance, not only on account of its afand further out of the labyrinths of ignorance, and fording to the frosted mariner in winter a convebring us nearer and nearer to the doors of ever- nient refuge from the snow storm, but because of lasting knowledge. Therefore, in the proposed un- its serving the Navigator with an excellent land dertaking, let not the utilitarian's question be sprung mark or beacon for our coast in all weathers. And too soon, or too loudly upon us.
so viewing it, the Doctor concealed the discovery, No part of the world affords a more difficult or for we were then at war with England. It was dangerous navigation than the approach of our then not uncommon for vessels to be as much as Northern coast in winter. Before the warmth of 10° out in their reckoning. He himself was 5o. the Gulf Stream was known, a voyage at this sea- Therefore, in approaching the coast, the current son from Europe to New England, New York, of warm water in the Gulf Stream, and of cold and even to the Capes of the Delaware or Chesa- water on this side of it, if tried with the thermomepeake, was many times more trying, difficult and ter, would enable the mariner to judge, with great dangerous, than it now is. In making this part of certainty and the worst of weather, as to his the coast, vessels are frequently met by snow position. Jonathan Williams afterwards, in speakstorms and gales which mock the seaman's strength ing of the importance which the discovery of these and set at naught his skill. In a little while, his warm and cold currents would prove to Navigabark becomes a mass of ice; with her crew frost- tion, pertinently asked the question-—"If these ed and helpless, she remains obedient only to her stripes of water had been distinguished by the helm, and is kept away for the Gulf Stream. colors of red, white and blue, could they be more After a few hours' run, she reaches its edge, and distinctly discovered than they are by the constant almost at the next bound, passes from the midst of use of the thermometer ?" And he might have winter into a sea at summer heat. The ice disap- added, could they have marked the position of the pears—the sailor bathes his stiffened limbs in tepid ship more clearly? waters; feeling himself invigorated and refreshed When his work on Thermometrical Navigation with the genial warmth about him, he realizes out appeared, Commodore Truxton wrote to him: there at sea, the fable of Antæus and his mother “ Your publication will be of use to Navigation, Earth. He attempts to make his port again, and by rendering sea voyages secure far beyond what is again as rudely met from the North West; but, even you yourself will immediately calculate, før each time he is driven off from the contest-he I have proved the utility of the thermometer very comes forth from this stream like the ancient son of often since we sailed together. Neptune, stronger and stronger, until, after many “ It will be found a most valuable instrument in days, his freshened strength prevails, and he at the hands of mariners, and particularly as to those last enters his haven in safety. I might name who are unacquainted with astronomical observainstances, for they are not uncommon, in which tions ; * * these particularly stand in need of a vessels bound to Norfolk or Baltimore with their simple method of ascertaining their approach to ar crews enervated in tropical climates, have encoun- distance from the coast, especially in the winter tered, as far down as the Capes of Virginia, snow season; for it is then that passages are often prostorms, that have driven them back into the Gulf longed, and ships blown off the coast by hard wesStream time and again, and have kept them out for terly winds, and vessels get into the Gulf Stream 40, 50, and even for 60 days, trying to make an without its being known ; on which account they anchorage.
are often hove to by the Captains supposing themThe number of shipwrecks that occurred on our selves near the coast, when they are very far off
, coast during one month in the winter of '41, amount- (having been drifted by the currents.) On the ed to not less than three a day. How many were other hand, ships are often cast on the coast, by saved by seeking refuge with their frosted and sailing in the eddy of the stream, which causes disabled crews in the warm waters of the Gulf'them to outrun their common, reckoning. Every
year produces new proofs of these facts, and of the and after the discovery of Dr. Franklin became calamities incident thereto."
generally known to Navigators. The comparison These obstructions to Navigation in winter must shows an immediate decline in the Southern trade therefore have operated strongly against the com- and a wonderful increase in that of the North. merce of the North, and in favor of that of the But whether this discovery in Navigation and this South. And as far as Philadelphia is concerned, revolution in trade stand in the relation of cause and which was the commercial emporium of the North effect, or be merely a coincidence let others judge. at that day, the list of arrivals there in winter, 60 In 1769, the commerce of the two Carolinas, or 70 years ago, shows that such was the case in equalled that of all the New England States toan eminent degree.
gether, it was more than double that of New York, Though the warm temperature of the Gulf and exceeded that of Pennsylvania by one third.* Stream was discovered in 1775, yet, for political In 1792, the exports from New York amounted in reasons, the discovery was not generally made value to two millions and a half; from Pennsylknown 'till 1790. Its immediate effect in Naviga- vania to $3,820,000; and from Charleston alone to tion, was to make the ports of the North as acces- $3,834,000. sible in winter as in summer. What agency this But in 1795, by which time the Gulf Stream circumstance had in the decline of the direct trade began to be as well understood by Navigators as of the South, which followed this discovery, would it now is, and the average passages from Europe be, at least to the political economist, a subject for to the North were shortened nearly one half, while mach curious and interesting speculation. I have those to the South remained about the same, the referred to the commercial tables of the time, and customs collected at Philadelphia alone amounted have compared the trade of Charleston with that to $2,941,000,+ or more than one half of those of the Northern cities for several years, both before collected in all the States together.
These statistics are given, and the subject is Moreover, it may, stay upon the lips of some
in such a field; but because they give point to il- Institute.
altogether insidious in its effects. By it, vessels
Massachusetts New York Pennsylvania Us. Carolina
1791 1,006,000 1,334,000 1,466,000
1792 723,000 1,173,000 1,100,000
1793 1,044,000 1,204,000 1,823,000
1794 1,121,000 1,878,000 1,498,000
1795 1.520,000 2,028,000 2,300,000
1796 1,460,000 2,187,000 2,050,000
1833 3,055,000 10,713,000 2,207,000
1 Doc. No. 330. H. R. 2nd Sess., 25 Congress.