NAVIGATION

, is the art of conducting a ship at sea from one port or place to another.

This is perhaps the most useful of all arts, and is of the highest antiquity. It may be impossible to fay who were the inventors of it; but it is probable that many people cultivated it, independent of each other, who inhabited the coasts of the sea, and had occasion, or found it convenient, to convey themselves upon the water from place to place; beginning from rafts and logs of wood, and gradually improving in the structure and management of their vessels, according to the length of time, and extent of their voyages. Writers however ascribe the invention of this art to different persons, or nations, according to their different sources of information. Thus,

The poets refer the invention of Navigation to Neptune, some to Bacchus, others to Hercules, to Jason, or to Janus, who it is said made the first ship. Historians ascribe it to the Æginetes, the Phœnicians, Tyrians, and the ancient inhabitants of Britain. Some are of opinion that the first hint was taken from the flight of the kite; and some, as Oppian (De Piscibus, lib. 1) from the fish called Nautilus; while others ascribe it to accident; and others again deriving the hint and invention from Noah's ark.

However, history represents the Phœnicians, especially those of the capital Tyre, as the first navigators that made any extensive progress in the art, so far as has come to our knowledge; and indeed it must have been this very art that made their city what it was. For this purpose, Lebanon, and the other neighbouring mountains, furnishing them with excellent wood for ship-building, they were speedily masters of a numerous fleet, with which constantly hazarding new navigations, and settling new trades, they soon arrived at an incredible pitch of opulence and populousness; so as to be in a condition to send out colonies, the principal of which was that of Carthage; which, keeping up their Phœnician spirit of commerce, in time far surpassed Tyre itself; sending their merchant ships through Hercules's pillars, now the straits of Gibraltar, and thence along the western coasts of Africa and Europe; and even, according to some authors, to America itself. The city of Tyre being destroyed by Alexander the Great, its Navigation and commerce were transferred by the conqueror to Alexandria, a new city, well situated for these purposes, and proposed for the capital of the empire of Asia, the conquest of which Alexander then meditated. And thus arose the Navigation of the Egyptians; which was afterwards so cultivated by the Ptolomies, that Tyre and Carthage were quite forgotten.

Egypt being reduced to a Roman province after the battle of Actium, its trade and Navigation fell into the hands of Augustus; in whose time Alexandria was only inferior to Rome; and the magazines of the capital of the world were wholly supplied with merchandizes from the capital of Egypt.

At length, Alexandria itself underwent the fate of Tyre and Carthage; being surprised by the Saracens, who, in spite of the emperor Heraclius, overspread the northern coasts of Africa, &c; whence the merchants being driven, Alexandria has ever since been in a languishing state, though still it has a considerable part of the commerce of the christian merchants trading to the Levant.

The fall of Rome and its empire drew along with it not only that of learning and the polite arts, but that of| Navigation also; the barbarians, into whose hands it fell, contenting themselves with the spoils of the industry of their predecessors.

But no sooner were the brave among those nations well settled in their new provinces; some in Gaul, as the Franks; others in Spain, as the Goths; and others in Italy, as the Lombards; but they began to learn the advantages of Navigation and commerce, with the methods of managing them, from the people they subdued; and this with so much success, that in a little time some of them became able to give new lessons, and set on foot new institutions for its advantage. Thus it is to the Lombards we usually ascribe the invention and use of banks, book-keeping, exchanges, rechanges, &c.

It does not appear which of the European people, after the settlement of their new masters, first betook themselves to Navigation and commerce.—Some think it began with the French; though the Italians seem to have the juster title to it, and are usually considered as the restorers of them, as well as of the polite arts, which had been banished together from the time the empire was torn asunder. It is the people of Italy then, and particularly those of Venice and Genoa, who have the glory of this restoration; and it is to their advantageous situation for Navigation that they in a great measure owe their glory. From about the time of the 6th century, when the inhabitants of the islands in the bottom of the Adriatic began to unite together, and by their union to form the Venetian state, their fleets of merchantmen were sent to all the parts of the Mediterranean; and at last to those of Egypt, particularly Cairo, a new city, built by the Saracen princes on the eastern banks of the Nile, where they traded for their spices and other products of the Indies. Thus they flourished, increased their commerce, their Navigation, and their conquests on the terra firma, till the league of Cambray in 1508, when a number of jealous princes conspired to their ruin; which was the more easily effected by the diminution of their EastIndia commerce, of which the Portuguese had got one part, and the French another. Genoa too, which had cultivated Navigation at the same time with Venice, and that with equal success, was a long time its dangerous rival, disputed with it the empire of the sea, and shared with it, the trade of Egypt; and other parts both of the east and west.

Jealousy soon began to break out; and the two republics coming to blows, there was almost continual war for three centuries, before the superiority was ascertained; when, towards the end of the 14th century, the battle of Chioza ended the strife: the Genoese, who till then had usually the advantage, having now lost all; and the Venetians almost become desperate, at one happy blow, beyond all expectation, secured to themselves the empire of the sea, and the superiority in commerce.

About the same time that Navigation was retrieved in the southern parts of Europe, a new society of merchants was formed in the north, which not only carried commerce to the greatest perfection it was capable of, till the discovery of the East and West Indies, but also formed a new scheme of laws for the regulation of it, which still obtain under the name of, Uses and Customs of the Sea. This society is that ce- lebrated league of the Hanse-towns, begun about the year 1164.

The art of Navigation has been greatly improved in modern times, both in respect of the form of the vessels themselves, and the methods of working or conducting them. The use of rowers is now entirely superceded by the improvements made in the sails, rigging, &c. It is also very probable, that the Ancients were neither so well skilled as the Moderns, in finding the latitudes, nor in steering their vessels in places of difficult Navigation, as the Moderns. But the greatest advantage which these have over the Ancients, is from the mariner's compass, by which they are enabled to find their way with as much facility in the midst of an immeasurable ocean, as the Ancients could have done by creeping along the coast, and never going out of sight of land. Some people indeed contend, that this is no new invention, but that the Ancients were acquainted with it. They say, it was impossible for Solomon's ships to go to Ophir, Tarshish, and Parvaim, which last they will have to be Peru, without this useful instrument. They insist, that it was impossible for the Ancients to be acquainted with the attractive virtue of the magnet, without knowing its polarity. They even affirm, that this property of the magnet is plainly mentioned in the book of Job, where the loadstone is called topaz, or the stone that turns itself. But, not to mention that Mr. Bruce has lately made it appear highly probable that Solomon's ships made no more than coasting voyages, it is certain that the Romans, who conquered Judea, were ignorant of this instrument; and it is very probable, that so useful an invention, if once it had been commonly known to a nation, would never have been forgotten, or perfectly concealed from so prudent a people as the Romans, who were so much interested in the discovery of it.

Among those who do agree that the mariner's compass is a modern invention, it has been much disputed who was the inventor. Some give the honour of it to Flavio Gioia of Amalfi in Campania, about the beginning of the 14th century; while others say that it came from the east, and was earlier known in Europe. But, at whatever time it was invented, it is certain, that the mariner's compass was not commonly used in Navigation before the year 1420. In that year the science was considerably improved under the auspices of Henry duke of Visco, brother to the king of Portugal. In the year 1485, Roderic and Joseph, physicians to king John the 2d of Portugal, together with one Martin de Bohemia, a Portuguese native of the island of Fayal, and pupil to Regiomontanus, calculated tables of the sun's declination for the use of sailors, and recommended the astrolabe for taking observations at sea. The celebrated Columbus, it is said, availed himself of Martin's instructions, and improved the Spaniards in the knowledge of this art; for the farther progress of which, a lecture was afterwards founded at Seville by the emperor Charles the 5th.

The discovery of the variation of the compass, is claimed by Columbus, and by Sebastian Cabot. The former certainly did observe this variation without having heard of it from any other person, on the 14th of September 1492, and it is very probable that Cabot might do the same. At that time it was found that there was no variation at the Azores, for which rea-| son some geographers made that the first meridian, though it has since been discovered that the variation alters in time. The use of the cross-staff now began to be introduced among sailors. This ancient instrument is described by John Werner of Nuremberg, in his annotations on the first book of Ptolomy's Geography, printed in 1514: he recommends it for observing the distance between the moon and some star, from which to determine the longitude.

At this time the art of Navigation was very imperfect, from the use of the plane chart, which was the only one then known, and which, by its gross errors, must have greatly misled the mariner, especially in places far distant from the equator; and also from the want of books of instruction for seamen.

At length two Spanish treatises came out, the one by Pedro de Medina, in 1545; and the other by Martin Cortes, or Curtis as it is printed in English, in 1556, though the author says he composed it at Cadiz in 1545, containing a complete system of the art as far as it was then known. Medina, in his dedication to Philip prince of Spain, laments that multitudes of ships daily perished at sea, because there were neither teachers of the art, nor books by which it might be learned; and Cortes, in his dedication, boasts to the emperor, that he was the first who had reduced Navigation into a compendium, valuing himself much on what he had performed. Medina defended the plane chart; but he was opposed by Cortes, who shewed its errors, and endeavoured to account for the variation of the compass, by supposing the needle was influenced by a magnetic pole, different from that of the world, and which he called the point attractive: which notion has been farther prosecuted by others. Medina's book was soon translated into Italian, French, and Flemish, and served for a long time as a guide to foreign navigators. However, Cortes was the favourite author of the English nation, and was translated in 1561, by Richard Eden, while Medina's work was much neglected, though translated also within a short time of the other. At that time a system of Navigation consisted of materials such as the following: An account of the Ptolomaic hypothesis, and the circles of the sphere; of the roundness of the earth, the longitudes, latitudes, climates, &c, and eclipses of the luminaries; a calendar; the method of finding the prime, epact, moon's age, and tides; a description of the compass, an account of its variation, for the discovering of which Cortes said an instrument might easily be contrived; tables of the sun's declination for 4 years, in order to find the latitude from his meridian altitude; directions to find the same by certain stars: of the course of the sun and moon; the length of the days; of time and its divisions; the method of finding the hour of the day and night; and lastly, a description of the sea-chart, on which to discover where the ship is; they made use also of a small table, that shewed, upon an alteration of one degree of the latitude, how many leagues were run on each rhumb, together with the departure from the meridian; which might be called a table of distance and departure, as we have now a table of difference of latitude and departure. Besides, some instruments were deseribed, especially by Cortes; such as, one to find the place and declination of the sun, with the age and place of the moon; certain dials, the astrolabe, and cross-staff; with a complex machine to discover the hour and latitude at once.

About the same time proposals were made for finding the longitude by observations of the moon. In 1530, Gemma Frisius advised the keeping of the time by means of small clocks or watches, then newly invented, as he says. He also contrived a new sort of cross-staff, and an instrument called the Nautical Quadrant; which last was much praised by William Cuningham, in his Cosmographical Glass, printed in the year 1559.

In the year 1537 Pedro Nunez, or Nonius, published a book in the Portuguese language, to explain a difficulty in Navigation, proposed to him by the commander Don Martin Alphonso de Susa. In this work he exposes the errors of the plane chart, and gives the solution of several curious astronomical problems; among which is that of determining the latitude from two observations of the sun's altitude and the intermediate azimuth being given. He observed, that though the rhumbs are spiral lines, yet the direct course of a ship will always be in the arch of a great circle, by which the angle with the meridians will continually change: all that the steersman can here do for preserving the original rhumb, is to correct these deviations as soon as they appear sensible. But thus the ship will in reality describe a course without the rhumb-line intended; and therefore his calculations for assigning the latitude, where any rhumb-line crosses the several meridians, will be in some measure erroneous. He invented a method of dividing a quadrant by means of concentric circles, which, after being much improved by Dr. Halley, is used at present, and is called a Nonius.

In 1577, Mr William Bourne published a treatise, in which, by considering the irregularities in the moon's motion, he shews the errors of the sailors in finding her age by the epact, and also in determining the hour from observing on what point of the compass the sun and moon appeared. In sailing towards high latitudes, he advises to keep the reckoning by the globe, as the plane chart is most erroneous in such situations. He despairs of our ever being able to find the longitude, unless the variation of the compass should be occasioned by some such attractive point as Cortes had imagined; of which however he doubts: but as he had shewn how to find the variation at all times, he advises to keep an account of the observations, as useful for finding the place of the ship; which advice was prosecuted at large by Simon Stevin in a treatise published at Leyden in 1599; the substance of which was the same year printed at London in English by Mr. Edward Wright, intitled the Haven-finding Art. In the same old tract also is described the way by which our sailors estimate the rate of a ship in her course, by the instrument called the Log. The author of this contrivance is not known; neither was it farther noticed till 1607, when it is mentioned in an East-India voyage published by Purchas: but from this time it became common, and mentioned by all authors on Navigation; and it still continues to be used as at first, though many attempts have been made to improve it, and contrivances proposed to supply its place; some of which have succeeded in still water, but proved useless in a stormy sea.|

In 1581 Michael Coignet, a native of Antwerp, published a Treatise, in which he animadverted on Medina. In this he shewed, that as the rhumbs are spirals, making endless revolutions about the poles, numerous errors must arise from their being represented by straight lines on the sea-charts; but though he hoped to find a remedy for these errors, he was of opinion that the proposals of Nonius were scarcely practicable, and therefore in a great measure useless. In treating of the sun's declination, he took notice of the gradual decrease in the obliquity of the ecliptic; he also described the Cross-Staff with three transverse pieces, as it was then in common use among the sailors. He likewise gave some instruments of his own invention; but all of them are now laid aside, excepting perhaps his Nocturnal. He constructed a sea-table, to be used by such as sailed beyond the 60th degree of latitude; and at the end of the book is delivered a Method of Sailing on a Parallel of Latitude, by means of a ring dial and a 24 hour glass.

In the same year Mr. Robert Norman published his Discovery of the Dipping-needle, in a pamphlet called the New Attractive; to which is always subjoined Mr. William Burroughs's Discourse of the Variation of the Compass.—In 1594, Capt. John Davis published a small treatise, entitled the Seaman's Secrets, which was much esteemed in its time.

The writers of this period complained much of the errors of the plane chart, which continued still in use, though they were unable to discover a proper remedy: till Gerrard Mercator contrived his Universal Map, which he published in 1569, without clearly understanding the principles of its construction: these were first discovered by Mr. Edward Wright, who sent an account of the true method of dividing the meridian from Cambridge, where he was a Fellow, to Mr. Blundeville, with a short table for that purpose, and a specimen of a chart so divided. These were published by Blundeville in 1594, among his Exercises; to the later editions of which was added his Discourse of Universal Maps, first printed in 1589. However, in 1599 Mr. Wright printed his Correction of certain Errors in Navigation, in which work he shews the reason of this division, the manner of constructing his table, and its uses in Navigation. A second edition of this treatise, with farther improvements, was printed in 1610, and a third edition by Mr. Moxon, in 1657.—The Method of Approximation, by what is called the middle latitude, now used by our sailors, occurs in Gunter's works, first printed in 1623.—About this time Logarithms began to be introduced, which were applied to Navigation in a variety of ways by Mr. Edmund Gunter; though the first application of the Logarithmic Tables to the Cases of Sailing, was by Mr. Thomas Addison, in his Arithmetical Navigation, printed in 1625.—In 1635 Mr. Henry Gellibrand printed a Discourse Mathematical on the Variation of the Magnetical Needle, containing his discovery of the changes to which the variation is subject.—In 1631, Mr. Richard Norwood published an excellent Treatise of Trigonometry, adapted to the invention of logarithms, particularly in applying Napier's general canons; and for the farther improvement of Navigation, he undertook the laborious work of measuring a degree of the meridian, for examining the divisions of the log-line. He has given a full and clear account of this operation in his Seaman's Practice, first published in 1637; where he also describes his own excellent method of setting down and perfecting a sea-reckoning, &c. This treatise, and that of Trigonometry, were often reprinted, as the principal books for learning scientifically the art of Navigation. What he had delivered, especially in the latter of them, concerning this subject, was contracted as a manual for sailors in a very small piece, called his Epitome, which has gone through a great number of editions.—About the year 1645, Mr. Bond published, in Norwood's Epitome, a very great improvement in Wright's method, by a property in his meridian line, by which its divisions are more scientifically assigned than the author was able to effect; which he deduced from this theorem, that these divisions are analogous to the excesses of the logarithmic tangents of half the respective latitudes increased by 45 degrees, above the logarithm of the radius: this he afterwards explained more fully in the 3d edition of Gunter's works, printed in 1653; and the demonstration of the general theorem was supplied by Mr. James Gregory of Aberdeen, in his Exercitationes Geometricæ, printed at London in 1668, and afterwards by Dr. Halley, in the Philos. Trans. numb. 219, as also by Mr. Cotes, numb. 388.—In 1700, Mr. Bond, who imagined that he had discovered the longitude, by having discovered the true theory of the magnetic variation, published a general map, on which curve lines were drawn, expressing the paths or places where the magnetic needle had the same variation. The positions of these curves will indeed continually suffer alterations; and therefore they should be corrected from time to time, as they have already been for the years 1744, and 1756, by Mr. William Mountaine, and Mr. James Dodson.—The allowances proper to be made for lee-way, are very particularly set down by Mr. John Buckler, and published in a small tract first printed in 1702, intitled a New Compendium of the whole Art of Navigation, written by Mr. William Jones.

As it is now generally agreed that the earth is a spheroid, whose axis or polar diameter is shorter than the equatorial diameter, Dr. Murdoch published a tract in 1741, in which he adapted Wright's, or Mercator's sailing to such a figure; and in the same year Mr. Maclaurin also, in the Philos. Trans. numb. 461, for determining the meridional parts of a spheroid; and he has farther prosecuted the same speculation in his Fluxions, printed in 1742.

The method of finding the longitude at sea, by the observed distances of the moon from the sun and stars, commonly called the Lunar method, was proposed at an early stage in the Art of Navigation, and has now been happily carried into effectual execution by the encouragement of the Board of Longitude, which was established in England in the year 1714, for rewarding any successful endeavours to keep the longitude at sea. In the year 1767, this Board published a Nautical Almanac, which has been continued annually ever since, by the advice, and under the direction of the astronomer royal at Greenwich: this work is purposely adapted to the use of navigators in long voyages, and, among a great many useful articles, contains tables of the| lunar distances accurately computed for every 3 hours in the year, for the purpose of comparing the diftance thus known for any time, with the distance observed in an unknown place, from whence to compute the longitude of that place. Under the auspices of this Board too, besides giving encouragement to the authors of many useful tables and other works, which would otherwise have been lost, time-keepers have been brought to a wonderful degree of perfection, by Mr. Harrison, Mr. Arnold, and many other persons, which have proved highly advantageous in keeping the time during long voyages at sea, and thence giving the longitude.

Some of the other principal writers on Navigation are Bartholomew Crescenti, of Rome, in 1607; Willebrord Snell, at Leyden, in 1624, his Typhis Batavus; Geo. Fournier, at Paris, 1633; John Baptist Riccioli, at Bologna, in 1661; Dechales, in 1674 and 1677; the Sieur Blondel St. Aubin, in 1671 and 1673; M. Dassier, in 1683; M. Sauveur, in 1692; M. John Bouguer, in 1698; F. Pezenas, in 1733 and 1741; and M. Peter Bouguer, who, in 1753, published a very elaborate treatise on this subject, intitled, Nouveau Traité de Navigation; in which he gives a variation compass of his own invention, and attempts to reform the Log, as he had before done in the Memoirs of the Academy of Sciences for 1747. He is also very particular in determining the lunations more accurately than by the common methods, and in describing the corrections of the dead reckoning. This book was abridged and improved by M. de la Caille, in 1760. To these may be added the Navigation of Don George Juan of Spain, in 1757. And, in our own nation, the several treatises of Messieurs Newhouse, Seller, Hodgson, Atkinson, Harris, Patoun, Hauxley, Wilson, Moore, Nicholson, &c; but, over all, The Elements of Navigation, in 2 vols, by Mr. John Robertson, first printed about the year 1750, and since often re-printed; which is the most complete work of the kind extant; and to which work is prefixed a Dissertation on the Rise and Progress of the modern Art of Navigation, by Dr. James Wilson, containing a very learned and elaborate history of the writings and improvements in this art.

For an account of the several instruments used in this art, with the methods for the longitude, and the various kinds and methods of Navigation, &c, see the respective articles themselves.

Navigation is either Proper or Common.

, Common, usually called Coasting, in which the places are at no great distance from one another, and the ship sails usually in sight of land, and mostly within soundings. In this, little else is required besides an acquaintance with the lands, the compass, and sounding-line; each of which, see in its place.

, Proper, is where the voyage is long, and pursued through the main ocean. And here, besides the requisites in the former case, are likewise required the use of Mercator's Chart, the azimuth and amplitude compasses, the log-line, and other instruments for celestial observations; as forestaffs, quadrants, and other sectors, &c.

Navigation turns chiefly upon four things; two of which being given or known, the rest are thence easily found out. These four things are, the difference of latitude, difference of longitude, the reckoning or distance run, and the course or rhumb sailed on. The latitudes are easily found, and that with sufficient accuracy: the course and distance are had by the log-line, or dead reckoning, together with the compass. Nor is there any thing wanting to the perfection of Navigation, but to determine the longitude. The mathematicians and astronomers of many ages have applied themselves, with great assiduity, to supply this grand desideratum, but not altogether with the success that was desired, considering the importance of the object, and the magnificent rewards offered by several states to the discoverer. See Longitude.

Sub-Marine Navigation, or the art of sailing under water, is mentioned by Mr. Boyle, as the desideratum of the art of Navigation. This, he says, was successfully attempted, by Cornelius Drebbel; several persons who were in the boat breathing freely all the time. See Diving-bell.

Inland Navigation, is that performed by small craft, upon canals &c, cut through a country.