Physical Geography Of The Sea 1855/introduction

From Wikisource
Jump to navigation Jump to search
Physical Geography Of The Sea (1855)
Matthew Fontaine Maury, Lieutenant, U.S.N.
Introduction
507535Physical Geography Of The Sea — Introduction1855Matthew Fontaine Maury, Lieutenant, U.S.N.

INTRODUCTION.



§ I. The primary object of “The Wind and Current Charts,” out of which has grown this Treatise on the Physical Geography of the Sea, was to collect the experience of every navigator as to the winds and currents of the ocean, to discuss his observations upon them, and then to present the world with the results on charts for the improvement of commerce and navigation.


II. Accordingly, when this object was made known, and an appeal was addressed to mariners, there was a flight up into the garrets, and a ransacking of time-honored sea chests in all the maritime communities of the country for old log books and sea journals.


III. It was supposed that the records therein contained as to winds and weather, the sea and its currents, would afford the information requisite for such an undertaking.


IV. By putting down on a chart the tracks of many vessels on the same voyage, but at different times, in different years, and during all seasons, and by projecting along each track the winds and currents daily encountered, it was plain that navigators hereafter, by consulting this chart, would have for their guide the results of the combined experience of all whose tracks were thus pointed out.


V. Perhaps it might be the first voyage of a young navigator to the given port, when his own personal experience of the winds to be expected, the currents to be encountered by the way, would itself be blank. If so, there would be the wind and current chart. It would spread out before him the tracks of a thousand vessels that had preceded him on the same voyage, wherever it might be, and that, too, at the same season of the year. Such a chart, it was held, would show him not only the tracks of the vessels, but the experience also of each master as to the winds and currents by the way, the temperature of the ocean, and the variation of the needle. All this could be taken in at a glance, and thus the young mariner instead of groping his way along until the lights of experience should come to him by the slow teachings of the dearest of all schools, would here find, at once, that he had already the experience of a thousand navigators to guide him on his voyage. He might, therefore, set out upon his first voyage with as much confidence in his knowledge as to the winds and currents he might expect to meet with, as though he himself had already been that way a thousand times before.


VI. But, to show the tracks of these vessels on a chart, a line had to be drawn for each one; now this, for so many, and all in black or blue, and on the same sheet of paper too, would present, it was perceived, a mass of lines in inextricable confusion. Moreover, after these tracks were projected, there would be no room left for the name of the month to show when each one was made, much less for any written account of the winds and currents daily encountered by each vessel of the multitude. After the tracks were projected, there would, it was found after trial, be barely room left on the chart to write the name of the vessel, much less the direction and set of the winds and currents.


VII. An appeal, it was consequently decided, should be taken to the most comprehensive sense of the five, and it was there upon resolved to address all those tracks, and winds, and currents, with their strength, set, and direction — in short, all this experience, knowledge, and information — to the eye, by means of colors and symbols.


VIII. The symbols devised with this view were a comet’s tail for the wind, an arrow for currents, Arabic numerals for the temperature of the sea, Roman for the variation of the needle, continuous, broken, and dotted lines for the month, and colors for the four seasons.


IX. A continuous line was used to show that the track was made during the first month; a broken, the second; and a dotted line, the last month of each season black standing for the winter, “green for spring, red for summer, and blue for autumn. The comet’s tail, and the arrow, and the numerals, were also in colors, according to the seasons. The force and direction of the wind were indicated by the shape and position of this tail; while the flight and length of the arrows designated the velocity and set of the currents.


XI. Thus the eye was successfully addressed; for, by a mere glance at the chart, the navigator saw in a moment from what quarter he might expect to find the wind in any part of the sea to prevail for any month; and he thus had to guide him across the pathless ocean, not theory or conjecture, nor the faint glimmerings of any one man’s experience, but the entire blaze and full flood of light which the observations of all the navigators that had preceded him could shed.


XII. Thus, while the young ship master, with these charts before him, would be immediately lifted up and placed on a footing with the oldest sea captains in this respect, the aged might see in these charts also the voyages made in their young days spread out before them. There, on the chart, was the ship’s name, her track, the year; and, by the color and fashion of the line (§ IX.), the month might be told. There, on that day, in that latitude and longitude, these charts would remind the old sailor that he had encountered a terrible gale of wind; there, that he had been beset with calms; how here, with fair winds and a smooth sea, he had made a glorious run. Here, he had first encountered the trades; and there, lost them. At this place, he had met with a “hawsing current.” Here, the winds were squally with rain; and there, it was he had been beset with fogs; here, with thunder storms. All this was seen on paper, and so represented as to recall the reality vividly to mind.


XIII. Such a chart could not fail to commend itself to intelligent ship masters, and such a chart was constructed for them. They took it to sea, they tried it, and to their surprise and delight they found that, with the knowledge it afforded, the remote corners of the earth were brought closer together, in some instances, by many days’ sail. The passage hence to the equator alone was shortened ten days. Before the commencement of this undertaking, the average passage to California was 183 days; but with these charts for their guide, navigators have reduced that average, and brought it down to 135 days.


XIV. Between England and Australia, the average time going, without these charts, is ascertained to be 124 days, and coming about the same; making the round voyage one of about 250 days on the average.


XV. These charts, and the system of research to which they have given rise, bid fair to bring that colony and the mother country nearer by many days, reducing, in no small measure, the average duration of the round voyage.[1]


XVI. At the meeting of the British Association of 1853, it was stated by a distinguished member —and the statement was again repeated at its meeting in 1854 — that in Bombay, whence he came, it was estimated that this system of research, if extended to the Indian Ocean, and embodied in a set of charts for that sea, such as I have been describing, would produce an annual saving to British commerce, in those waters alone, of one or two millions of dollars;[2] and in all seas, of ten millions. [3]


XVII. A system of philosophical research, which is so rich with fruits and abundant with promise, could not fail to attract the attention and commend itself to the consideration of the seafaring community of the whole civilized world. It was founded on observation; it was the result of the experience of many observant men, now brought together for the first time and patiently discussed. The results tended to increase human knowledge with regard to the sea and its wonders, and therefore they could not be wanting in attractions to right-minded men.


XVIII. As we went on with our labors in this field, it was found that the flight into the garret and the dive into the sea chests for old logs (§ II.) were not sufficient. The old records thence turned up proved to be only outcroppings to the rich vein which had been struck; but the indications which they gave of hidden treasure were unmistakable to the nautical mind of the world. It was found necessary to go deeper, and to observe more minutely than our ancestors of the sea had done.


[1] The outward passage, it has since been ascertained, has been reduced to 97 days on the average.


[2] “Now let us make a calculation of the annual saving to the commerce of the United States effected by those charts and sailing directions. According to Lieutenant Maury, the average freight from the United States to Rio Janeiro is 17.7 cts. per ton per day; to Australia, 20 cts.; to California, also, about 20 cts. The mean of this is a little over 19 cents per ton per day; but to be within the mark, we will take it at 15, and include all the ports of South America, China, and the East Indies.


“Lieutenant Matthew Maury’s Sailing Directions have shortened the passages to California 30 days, to Australia 20, to Rio de Janeiro 10. The mean of this is 20, but we will take it at 15, and also include the above named ports of South America, China, and the East Indies.


“We estimate the tonnage of the United States engaged in trade with these places at 1,000,000 tons per annum.


“With this data, we see that there has been effected a saving for each one of these tons of 15 cents per day for a period of 15 days, which will give an aggregate of $2,250,000 saved per annum. This is on the outward voyage alone, and the tonnage trading with all other parts of the world is also left out of the calculation. Take these into consideration, and also the fact that there is a vast amount of foreign tonnage trading between these places and the United States, and it will be seen that the annual sum saved will swell to an enormous amount!"—Extract from Hunt’s Merchant’s Magazine, May, 1854.


[3] See Inaugural Address of the Earl of Harrowby, President of the British Association at its twenty-fourth meeting. Liverpool, 1854.


XIX. Accordingly, it was deemed advisable to make an exhibit of what had been obtained from the old sea-chests. This was done, and presented to mariners in the shape of a set of “Track Charts” for the North Atlantic Ocean.


XX. On those charts all the tracks that could be collected at that time from the old sea-journals were projected, and one was surprised to see how they cut up and divided the ocean off into great turnpike-looking thoroughfares. There was the road to China: it, and the road to South America, to the Pacific around Cape Horn, to the East around the Cape of Good Hope, and to Australia, were one and the same until the navigator had left the North, crossed the equator, and passed over into the South Atlantic. Here there was, in this great highway, a fork to the right, leading to the ports of Brazil. A little farther on you came to another on the left: it was the road by which the Cape of Good Hope was to be doubled. There was no finger-board or other visible sign to guide the wayfarer, but, nevertheless, all turned off at the same place. None missed it.


XXI. This outward road to India and the gold fields of Australia was, as it passed through the South Atlantic, a crooked one, but the road home from the Cape was straight, for the winds along it were fresh and fair.


XXII. But the outward-bound route through the North Atlantic, from the United States especially, was most curious and crooked. It seemed, on the chart, to be as well beaten, and almost as well defined, as any Indian trail through the wilderness. First it struck across the Atlantic until it reached the Cape Verde Islands on the other side; then it took a turn, and came back on this side again, reaching the coast of Brazil in the vicinity of Cape St. Roque. Here there was another turn, and another recrossing of the broad ocean, striking this time for the Cape of Good Hope, but bending far away to the right before that turning point was reached.


XXIII. Thus the great highway from the United States to the Cape of Good Hope nearly crossed the Atlantic, it was discovered, three times. The other parts of the ocean by the wayside were blank, untraveled spaces. All the vessels that sailed went by one road and returned by the other. Now and then there was a sort of a country cross-road, that was frequented by robbers and bad men as they passed on their voyage from Africa to the West Indies and back. But all the rest of the ocean on the wayside, and to the distance of hundreds of miles on either hand, was blank, and seemed as untraveled and as much out of the way of the haunts of civilized man as are the solitudes of the wilderness that lie broad off from the emigrants trail to Oregon. Such was the old route.


XXIV. Who were the engineers that laid out these highways upon the sea, and why did traders never try short cuts across the blank spaces? There was neither rock, nor shoal, nor hidden danger of any sort to prevent; why did not traders, therefore, seek to cut off these elbows in the great thoroughfares, and, instead of crossing the Atlantic three times on their way to the Cape of Good Hope (§ XXII.), cross it only once, as they did coming home? Who, it was repeated, were the hydrographic engineers concerned in the establishing of this zigzag route?


XXV. Inquiry was instituted, and, after diligent research, it was traced, by tradition, to the early navigators and the chance that directed them. When they set sail from Europe, seeking a passage to the East via the Cape of Good Hope, they passed along down by the Cape Verde Islands, and then, as they approached the equator, the winds forced them over toward the coast of Brazil. Thus a track was made, and the route to the East laid out.


XXVI. As one traveler in the wilderness follows in the trail of another, so, it was discovered, did the trader on the high seas following in the wake of those who had led the way. The pioneer goes and returns: ‘Which way did you go? How lies the route? Give us your sailing directions,” say his followers.


XXVII. He that is questioned can speak only of the route by which he went and came. He knows of no others; and this, therefore, he commends to his followers, and they to those who come after them; and thus, in many cases, the route from place to place across the sea was, it was ascertained, handed down from sailor to sailor by tradition, or as legend, and very much in the same way that the overland route of the first emigrants to California continued to be followed season after season.


XXVIII. Among other things, these legends told of the most sweeping currents to the north of St. Roque, along the coast of Brazil. The vessel, said they, that should fall so far to leeward of that cape and coast as to come within the influence of these currents, was almost sure to be beset, and her crew to be cast upon an iron-bound coast amid the horrors of shipwreck.


XXIX. Now these investigations have proved that there is no current there worth the name, and no danger to be apprehended when it is encountered, and so mariners now allude to these currents as the “bugbear” of St. Roque.


XXX. Nevertheless, impressed with these legends and traditions, the early navigators of this country, when they first commenced to double the Cape of Good Hope on trading voyages, thought it most prudent to make the best of their way to the route from Europe, which had been often tried and was well known. They aimed to fall in with this route about the Cape Verde Islands. The winds there threw them back on this side of the Atlantic, upon the coast of Brazil, and so they had to cross the ocean again to reach the Cape of Good Hope. But every body said that was the way, and it was so written down in the books. Hence the zigzag route (§ XXII.), and the supposed necessity, on the out-ward voyage to India, of crossing the Atlantic Ocean three times instead of once.


XXXI. The results of the first chart, however (§ XIII.), though meagre and unsatisfactory, were brought to the notice of navigators; their attention was called to the blank spaces, and the importance of more and better observations than the old sea-chests generally contained was urged upon them.


XXXII. They were told that if each one would agree to cooperate in a general plan of observations at sea, and would send regularly, at the end of every cruise, an abstract log of their voyage to the National Observatory at Washington, he should, for so doing, be furnished, free of cost, with a copy of the charts and Sailing Directions that might be founded upon those observations.


XXXIII. The quick, practical mind of the American ship-master took hold of the proposition at once. To him the field was inviting, for he saw in it the promise of a rich harvest and of many useful results.


XXXIV. So, in a little while, there were more than a thousand navigators engaged day and night, and in all parts of the ocean, in making and recording observations according to a uniform plan, and in furthering this attempt to increase our knowledge as to the winds and currents of the sea, and other phenomena that relate to its safe navigation and physical geography.


XXXV. To enlist the service of such a large corps of observers, and to have the attention of so many clever and observant men directed to the same subject, was a great point gained: it was a giant stride in the advancement of knowledge, and a great step toward its spread upon the waters.


XXXVI. Important results soon followed, and great discoveries were made. These attracted the attention of the commercial world, and did not escape the notice of philosophers every where.


XXXVII. The field was immense, the harvest was plenteous, and there was both need and room for more laborers. Whatever the reapers should gather, or the merest gleaner collect, was to inure to the benefit of commerce and navigation — the increase of knowledge — the good of all.


XXXVIII. Therefore, all who use the sea were equally interested in the undertaking. The government of the United States, so considering the matter, proposed a uniform system of observations at sea, and invited all the maritime states of Christendom to a conference upon the subject.


XXXIX. This Conference, consisting of representatives from France, England, and Russia, from Sweden and Norway, Holland, Denmark, Belgium, Portugal, and the United States, met in Brussels, August 23, 1853, and recommended a plan of observations which should be followed on board the vessels of all friendly nations, and especially of those there present in the persons of their representatives.


XL. Prussia, Spain, the free city of Hamburg, the republics of Bremen and Chili, and the Empires of Austria and Brazil, have since offered their cooperation also in the same plan.


XLI. Thus the sea has been brought regularly within the domains of philosophical research, and crowded with observers.


XLII. In peace and in war these observations are to be carried on; and, in case any of the vessels on board of which they are conducted may be captured, the abstract log — as the journal which contains these observations is called — is to be held sacred.


XLIII. Baron Humboldt is of opinion that the results already obtained from this system of research are sufficient to give rise to a new department of science, which he has called the PHYSICAL GEOGRAPHY OF THE SEA. If so much have already been accomplished by one nation, what may we not expect in the course of a few years from the joint cooperation of so many?


XLIV. Rarely before has there been such a sublime spectacle presented to the scientific world: all nations agreeing to unite and cooperate in carrying out one system of philosophical research with regard to the sea. Though they may be enemies in all else, here they are to be friends. Every ship that navigates the high seas with these charts and blank abstract logs on board may henceforth be regarded as a floating observatory, a temple of science. The instruments used by every cooperating vessel are to be compared with standards that are common to all; so that an observation that is made any where and in any ship, may be referred to and compared with all similar observations by all other ships in all other parts of the world. But these meteorological observations which this extensive and admirable system includes will relate only to the sea. It is a pity. The plan should include the land also, and be universal. It is now proposed to have another and general meteorological congress; and the initiatory steps, by way of counsel, for calling it together, have been taken, both in England and on the Continent. It is to be hoped that this country will not fail to cooperate in such a humane, wise, and noble undertaking as is this. It involves a study of the laws which regulate the atmosphere, and a careful investigation of all its phenomena.


XLV. Another beautiful feature in this system is, that it costs nothing additional. The instruments that these observations call for are such as are already in use on board of every well-conditioned ship, and the observations that are required are precisely those which are necessary for her safe and proper navigation.


XLVI. As great as is the value attached to what has been accomplished by these researches in the way of shortening passages and lessening the dangers of the sea, a good of higher value is, in the opinion of many seamen, yet to come out of the moral, the educational, influence which they are calculated to exert upon the seafaring community of the world. A very clever English shipmaster, speaking recently of the advantages of educational influences among those who intend to follow the sea, remarks:— “To the cultivated lad there is a new world spread out when he enters on his first voyage. As his education has fitted, so will he perceive, year by year, that his profession makes him acquainted with things new and instructive. His intelligence will enable him to appreciate the contrasts of each country in its general aspect, manners, and productions, and in modes of navigation, adapted to the character of coast, climate, and rivers. He will dwell with interest on the phases of the ocean, the storm, the calm, and the breeze, and will look for traces of the laws which regulate them. All this will induce a serious earnestness in his work, and teach him to view lightly those irksome and often offensive duties incident to the beginner.”[4] Sentiments which can not fail to meet with a hearty response from all good men, whether ashore or afloat.


[4] “THE LOG OF A MERCHANT OFFICER”; viewed with reference to the Education of young Officers and the Youth of the Merchant Service. By Robert Methren, commander in the Peninsular and Oriental Company, and author of the “ ‘Narrative of the Blenheim Hurricane of 1851.’ ” London: John Weale, 59 High Holborn; Smith, Elder & Co., Cornhill; Ackerman & Co., Strand. 1854.


XLVII. Never before has such a corps of observers been enlisted in the cause of any department of physical science as is that which is now about to be engaged in advancing our knowledge of the physical geography of the sea, and never before have men felt such an interest with regard to this knowledge.


Under this term will be included a philosophical account of the winds and currents of the sea; of the circulation of the atmosphere and ocean; of the temperature and depth of the sea; of the wonders that are hidden in its depths; and of the phenomena that display themselves at its surface. In short, I shall treat of the economy of the sea and its adaptations — of its salts, its waters, its climates, and its inhabitants, and of whatever there may be of general interest in its commercial uses or industrial pursuits, for all such things pertain to its PHYSICAL GEOGRAPHY.


XLVIII. The object of this little book, moreover, is to show the present state, and, from time to time, the progress of this new and beautiful system of research, as well as of this interesting department of science; and the aim of the author is to present the gleanings from this new field in a manner that may be interesting and instructive to all, whether old or young, ashore or afloat, who desire a closer look into “the wonders of the great deep,” or a better knowledge as to its winds, its adaptations, or its Physical Geography.[5]


[5] There is an old and very rare book which treats upon some of the subjects to which this little work relates. It is by Count L. F. Marsigli, a Frenchman, and is called Natural Description Of The Seas. The copy to which I refer was translated into Dutch by Boerhaave in 1786.


The French count made his observations along the coast of Provence and Languedoc. The description only relates to that part of the Mediterranean. The book is divided into four chapters: the first, on the bottom and shape of the sea; the second, of sea water; the third, on the movements of sea water; and the fourth, of sea plants.


He divides sea water into surface and deep-sea water; because, when he makes salt from surface water (not more than half a foot below the upper strata), this salt will give a red color to blue paper; whereas the salt from deep-sea water will not alter the colors at all. The blue paper can only change its color by the action of an acid. The reason why this acid (iodine.) is found in surface and not in deep-sea water is: it is derived from the air; but he supposes that the saltpetre that is found in sea water, by the action of the sun’s rays and the motion of the waves, is deprived of its coarse parts, and, by evaporation, embodied in the air, to be conveyed to beasts or plants for their existence, or deposed upon the earth’s crust, as it occurs on the plains of Hungary, where the earth absorbs so much of this saltpetre vapor.


Donati, also, was a valuable laborer in this field. His inquiries enabled Mr. Trembleya to conclude that there are, “at the bottom of the water, mountains, plains, valleys, and caverns, just as upon the land.” But by far the most interesting and valuable book touching the physical geography of the Mediterranean is Admiral Smyth’s last work, entitled “The Mediterranean; A Memoir, Physical, Historical, And Nautical.” By Rear-Admiral William Henry Smyth, K.S.F., D.C.L.,” &c. London: John W. Parker and Son. 1854.