went considerably better than Mr. Harrison's did. Mr. Kendal's watch was sent out with Captain Cook, in his second voyage towards the south pole and round the globe, in the years 1772, 1773, 1774, and 1775: when the only fault found in the watch was, that its rate of going was continually accelerated; though in this trial, of three years and a half, it never amounted to 14h a day. The consequence was, that the House of Commons in 1774, to whom an appeal had been made, were pleased to order the second moiety of the reward to be given to Mr. Harrison, and to pass the act above mentioned. Mr. Harrison had also at different times received some other sums of money, as encouragements to him to continue his endeavours, from the board of longitude, and from the India company, as well as from many individuals. Mr. Arnold, Mr. Earnshaw, and som other persons, have since also made several very good watches for the same purpose.

Others have proposed various astronomical methods for finding the longitude. These methods chiefly depend on having an ephemeris or almanac suited to the meridian of some place, as Greenwich for instance, to which the Nautical Almanac is adapted, which shall contain for every day computations of the times of all remarkable celestial motions and appearances, as adapted to that meridian. So that, if the hour and minute be known when any of the same phenomena are observed in any other place, whose longitude is desired, the difference be tween this time and that to which the time of the said phenomenon was calculated and set down in the almanae will be known, and consequently the difference of longitude also being so known between that place and Greenwich, allowing at the rate of 15 degrees to an hour.

Now, it is easy to find the time at any place, by means of the altitude or azimuth of the sun or stars; which time it is necessary to find by such means, both in these astronomical modes of determining the longitude, and in the former by a time-keeper; and it is the difference between that time, so determined, and the time at Greenwich, known either by the timekeeper or by the astronomical observations of celestial phenomena, which gives the difference of longitude, at the rate above mentioned. Now, the difficulty in these methods lies in the fewness of proper phenomena capable of being thus observed; for all slow motions, such as belong to the planet Saturn for instance, are quite excluded, as affording too small a difference, in a considerable space of time, to be properly observed; and it appears that there are no phenomena in the heavens proper for this purpose, except the eclipses or motions of Jupiter's satellites, and the eclipses or motions of the moon, viz. such as her distance from the sun or certain fixed stars lying near her path, or her longitude or place in the zodiac, &c. Now of these methods,

Ist, That by the eclipses of the moon is very easy, and sufficiently accurate, if they did but happen often, as every night. For at the moment when the beginning, or middle, or end of an eclipse is observed by a telescope, there is no more to be done, but to determine the time by observing the altitude or azimuth of some known star; which time being compared with that in the tables, set down for the happening of the same phenomenon at Greenwich, gives the difference in time, and consequently of longitude sought. But as the beginning or end of an eclipse of the moon cannot generally be observed nearer than one minute, and sometimes two or three minutes of time, the longitude cannot certainly be de

termined by this method, from a single observation, nearer than one degree of longitude. However, by two or more observations, as of the beginning and end, &c. a much greater degree of exactness may be

attained.

2d, The moon's place in the zodiac is a phenomenon more frequent than that of her eclipses; but then the observation of it is difficult, and the calculus perplexed and intricate, by reason of two parallaxes; so that it is hardly practicable, to any tolerable degree of

accuracy.

3d, The longitude may be found by the Moon's culminating, thus: - Seek in the ephemeris for the time of her coming to the meridian on the given day, and on the day following, and take their difference; also take the difference betwixt the times of culminating on the same day, as found in the ephemeris, and as observed; then say. As the daily difference in the ephemeris is to the difference between the ephemeris and observation; so is 360 degrees to the difference of longitude. In this method, however, a small difference in the culmination will occasion a great one in the longitude.

4th, But the moon's distances from the sun, or certain fixed stars, are phenomena to be observed many times in almost every night, and afford a good practical method of determining the longitude of a ship at almost any time; either by computing, from thence, the moon's true place, to compare with the same in the almanac; or by comparing her observed distance itself with the same as there set down.

It is said that the first person who recommended the finding the longitude from this observed distance between the moon and some star, was John Werner, of Nuremberg, who printed his annotations on the first book of Ptolemy's Geography in 1514. And the same thing was recommended in 1524 by Peter Apian, professor of mathematics at Ingolstadt; also about 1530, by Oronce Finé, of Briançon; and the same year by the celebrated Kepler, and by Gemma Frisius, at Antwerp; and in 1500 by Nonius, or Pedro Nunez.

Nor were the English mathematicians behind-hand on this head. In 1665, Sir Jonas Moore prevailed on King Charles the Second to erect the Royal Observatory at Greenwich, and to appoint Mr. Flamsteed his astronomical observer, with this express command, that he should apply himself with the utmost care and diligence to the rectifying the table of the motions of the heavens, and the places of the fixed stars, in order to find out the so much desired longitude at sea, for perfecting the art of navigation. And to the fidelity and industry with which Mr. Flamsteed executed his commission it is that we are chiefly indebted for that curious theory of the moon, which was afterwards formed by the immortal Newton. This incomparable philosopher made the best possible use of the observations with which he was furnished; but as these were interrupted and imperfect, his theory would sometimes differ from the heavens by 5 minutes or

more.

Dr. Halley bestowed much time on the same object; and a Starry Zodiac was published under his direction, containing all the stars to which the moon's appulse can be observed; but for want of correct tables, and proper instruments, he could not proceed in making the necessary observations. In a paper on this subject in the Philos. Trans. number 421, he expresses his hope, that the instrument just invented by Mr. Hadley might be applied to taking angles at sea with the desired accuracy. This great astronomer, and after him the Abbé de la Caille, and others, have reckoned the best astronomical method for finding the longitude at sea, to be that in which the distance of the moon from the sun or from a star is used; for the moon's daily motion being about 13 degrees, her hourly mean motion is above half a degree, or one minute of a degree in two minutes of time; so that an error of one minute of a degree in position will produce an error of two minutes in time, or half a a degree in longitude. Now from the great improvements made by Newton in the theory of the moon, and more lately by Euler and others on his principles, professor Mayer, of Gottengen, was enabled to calculate lunar tables more correct than any former ones; having so far succeeded as to give the moon's place within one minute of the truth, as has been proved by a comparison of the tables with the observations made at the Greenwich observatory by the late Dr. Bradley, and by Dr. Maskelyne, the present astronomer royal: the same have been still farther improved under his direction by the late Mr. Charles Mason, by several new equations, and the whole computed to tenths of a second. These new tables, when compared with the above-mentioned series of observations, a proper allowance being made for the unavoidable error of observation, seem to give always the moon's longitude in the heavens correctly within 30 seconds of a degree; which greatest error, added to a possible error of one minute in taking the moon's distance from the sun or a star at sea, will at a medium only produce an error of 42 minutes of longitude. To facilitate the use of the tables, Dr. Maskelyne proposed a nautical ephemeris, the scheme of which was adopted by the commissioners of longitude, and first executed in the year 1767, since which time it has been regularly continued, and published as far as for the year 1800. But as the rules that were given in the appendix to one of those publications, for correcting the effects of refraction and parallax, were thought too difficult for general use, they have been reduced to tables. So that, by the help of the ephemeris, these tables, and others that are also provided by the board of longitude, the calculations relating to the longitude, which could not be performed by the most expert mathematician in less than four hours, may now be completed with great ease and accuracy in half an hour.

As this method of determining the longitude depends on the use of the tables annually published for this purpose, those who wish for further information are referred to the instructions that accompany them, and particularly to those that are annexed to the tables requisite to be used with the Astronomical and Nautical Ephemeris, 3d edit. Also to Mackay's useful treatise on The Theory and Practice of finding the Longitude at Sea or Land, and to capt. Mendoza Rios's Complete Collection of Tables for Navigation and Nautical Astronomy, where the ingenious formulæ given by himself, by the late Mr. H. Cavendish, and others, are illus trated and exemplified.

5th, The phenomena of Jupiter's satellites have commonly been preferred to those of the moon for finding the longitude; because they are less liable to parallaxes than these are, and besides they afford a very commodious observation whenever the

planet is above the horizon. Their motion is very swift, and must be calculated for every hour. These satellites of Jupiter were no sooner announced by Galileo, in his Syderius Nuncius, first printed at Venice in 1610, than the frequency of their eclipses recommended them for this purpose; and

among those who treated on this subject, none was more successful than Cassini. This great astronomer published, at Bologna, in 1688, tables for calculating the appearances of their eclipses, with directions for finding the longitudes of places by them; and being invited to France by Louis the Fourteenth, he there, in the year 1693, published more correct tables of the same. But the mutual attractions of the satellites rendering their motions very irregular, those tables soon became useless for this purpose; insomuch that they require to be renewed from time to time; a service which has been performed by several ingenious astronomers, as Dr. Pound, Dr. Bradley, M. Cassini the son, and more especially by Mr. Wargentin, whose tables are much esteemed, which have been published in several places, as also in the Nautical Almanacs for 1771 and 1779.

Now, to find the longitude by these satellites ; with a good telescope observe some of their phenomena, as the conjunction of two of them, or of one of them with Jupiter, &c.; and at the same time find the hour and minute, from the altitudes of the stars, or by means of a clock or watch, previously regulated for the place of observation; then, consulting tables of the satellites, observe the time when the same appearance happens in the meridian of the place for which the tables are calculated; and the difference of time, as before, will give the longitude.

The eclipses of the first and second of Jupiter's satellites are the most proper for this purpose; and as they happen almost daily, they afford a ready means of determining the longitude of places at land, having indeed contributed much to the modern improvements in geography; and if it were possible to observe them with proper telescopes in a ship under sail, they would be of great service in ascertaining its longitude from time to time. To obviate the inconvenience to which these observations are liable from the motions of the ship, a Mr. Irwin invented what he called a marine chair; this was tried by Dr. Maskelyne in his voyage to Barbadoes, when it was not found that any benefit could be derived from the use of it. Indeed, considering the great power requisite in a telescope proper for these observations, and the violence, as well as the irregularities in the motion of a ship, it is to be feared that the complete management of a telescope on ship-board will always remain among the desiderata in this part of nautical science. Farther, since all methods that depend on the phenomena of the heavens have also this other defect, that they cannot be observed at all times, this renders the improvement of time-keepers of the greater importance.

For approximate constructions for clearing the lunar distances from the effects of parallax and refraction, the reader may consult Kelly's Spherics and Nautical Astronomy, H. Clarke's Seaman's Desiderata and Repertory of Arts, &c. vol. v. And for more detailed information respecting the above and other methods of ascertaining the longitude, see Dr. Mackay's and Mr. Mendoza Rios's valuable works already referred to; also Vince's Astronomy, vol. 2, p. 515 to 560, and O. Gregory's Astronomy, p. 446 to 470.

LONGITUDINAL. a. (longitudinal, Fr.) Measured by the length; running in the longest direction (Cheyne). LONGITUDINAL SINUS.

In anatomy. Longitudinal sinus of the dura mater. A triangular canal, proceeding in the falciform pro

A. Stem twining.

B. Peduncles two-flowered.

C. Stem erect; peduncles many-flowered. The following are the chief varieties:

lavers

1. L. semper virens. Trumpet-flowered evergreen honeysuckle, a native of Mexico and Virginia; naked terminal spikes; leaves oblong, the uppermost united and perfoliate; corols nearly equal; the tube dilated upwards. The flowers are of a deep scarlet hue, very beautiful, but nearly inodorous. The plant may be propagated by layers, cuttings, or seeds. The should be put down in the autumn, and by the ensuing autumn they will have taken root, and may be cut from the parent plant and removed to the place for which they are designed. If propagated by cuttings, the cuttings should be planted in September, as soon as the ground is moistened by rain. They should have four joints, of which three are to be buried in the ground. If seeds be used, they should be sown in the autumn, soon after they are ma tured, as otherwise the plant will not spring up the first year: they thrive best in a sandy loani. 2. L. Caprifolium. Italian honeysuckle. Flowers ungent, whaled, terminal, white, red, and yellow, and very fragrant. Found largely in Italy, but also in the woods of our own country. It may be propagated as the last.

3. L. Alpigena. Upright red-berried honeysuckle. Peduncles two-flowered; berries closely united, in pairs; leaves oval-lanceolate; stem four or five feet high; corols red, unequal. A native of the Alps, and propagated as the last.

4. L. Nigra. Black-berried upright honeysuckle. Peduncles 2-flowered; berries distinct; leaves elliptic, very entire. Stem about three feet high; flowers white, succeeded by black berries. A native of the South of Europe.

5. L. Xylosteum. Fly-honeysuckle. Peduncles two-flowered; berries distinct; leaves entire, downy; corols white. Stem shrubby, branching erect to the height of seven or eight feet. A native of Europe, and found frequently in our own coppices.

6. L. Symphoricarpos. Shrubby St. Peter'swort, Heads of flowers lateral, peduncled; leaves petioled: small greenish flowers. A native of Virginia and Carolina.

7. L. Diervilla. Arcadian honeysuckle. Racemes terminal; leaves serrate: flowers small, pale yellow: appear in May or June, and continue till the autumn; but rarely ripen in our own country. A native of New York.

8. L. Periclimenum. Common climbing honeysuckle. Heads ovate, imbricate, terminal; leaves deciduous, all of them distinct; flowers

ringent. Another variety with leaves sinuate, often variegated. Common to our own hedges.

9. L. Tartarica. Tartarian honeysuckle. Peduncles two-flowered; berries distinct; leaves heart-shaped, obtuse, glabrous: flowers white, erect. A native of Tartary.

10. L. cærulea. Blue-berried honeysuckle. Peduncles two flowered; berries closely united, globular; styles undivided; yellow bark and yellow flowers. A native of Switzerland. The modes of propagation pointed out under the first species will, with little variation, apply to all the rest.

LONICERUS (John), a learned German, born at Orthern. He was a protestant, and published a Greek and Latin Lexicon, and some other works. He died in 1569.

LONICERUS (Adam), son of the preceding, was bred a physician, and wrote several books on natural history; particularly a History of Plants, Animals, and Metals. He died at Frankfort in 1586.

LONSDALE. See KIRKBY LONSDALE.

LOO or LUE. (luer, Fr.) A game at cards called also LANTERLOO, which see.

Loo, a town of the United Provinces, in Guelderland, eight miles west of Deventer, where the prince of Orange had a fine palace. Lon. 6.0 E. Lat. 52. 18 N.

LOOE, East and West, two mean boroughs in Cornwall, separated by a creek, over which is a narrow stone bridge. They send together as many members to parliament as London. The market held at East Love is on Saturday. They are 16 miles W. of Plymouth, and 232 W. by S. of London. Lon. 4. 36 W. Lat. 50. 23 N.

LOO BILY. a. (looby and like.) Awkward; clumsy (L'Estrange).

LOOBY. s. (labe, a clown, Welsh.) A lubber; a clumsy clown (Swift).

LOOF. 8. That part aloft of the ship which lies just before the chess-trees, as far as the bulk-head of the castle (Sea Dictionary).

To Loor. v. a. To bring the ship close to a wind.

LOO FED. a. (from aloof.) Gone to a distance (Shakespeare).

Το LOOK. v. n. (locan, Saxon.) 1. To direct the eye to or from any object. 2. To have power of seeing (Dryden). 3. To direct the intellectual eye (Stillingfivet). 4. To expect (Claren.). 5. To take care; to watch (Locke). 6. To be directed with regard to any object (Proverbs). 7. To have any particular appearance; to seem (Burnet). 8. To have any air, mien, or manner (Shak.). 9. To form the air in any particular manner, in regarding or beholding (Milton). 10. To Look about one. To be alarmed; to be vigilant. (Har.) 11. To Look after. To attend; to take care of (Loc.). 12. To Look for. To expect (Sidney). 13. To Look into. To examine; to sift; to inspect closely (Atterbury). 14. To Look on. To re. spect; to esteem; to regard as good or bad (Dryden). 15. To Look on. To consider; to conceive of; to think (South). 16. To Look on. To be a mere idle spectator (Bacon), 17. To Look over. To examine; to try one by one (Locke). 18. Το Look out. To search; to seck (Sw.). 19. To Look out. To be on the watch (Coll.). 20. To Look to. To watch; to take care of (Shakespeare). 21. To Look to. To behold.

Το Look. v. a. 1. To seck; to search for (Spenser). 2. To turn the eye upon (Kings). 3. To influence by looks (Dryden). 4. To Look out. To discover by searching.

Look. interj. See! lo! behold! observe! (Shakspeare).

Look. s. 1. Air of the face; mien; cast of the countenance (Shaks.). 2. The act of look ing or seeing (Dryden).

LOOKER. 3. (from look.) 1. One that looks. 2. LOOKER on. Spectator, not agent (Add.).

LOOKING-GLASS. 8. (look and glass.) Mirror; a glass which shows forms reflected (Shakspeare).

LOOKING-GLASS PLANT. See HERITEIRA.
LOOKING GLASS (Venus's). See CAMPA-

NULA.

LOOL, in metallurgy, a vessel made to receive the washings of ores of metals. The heavier or more metalline parts of the ores remain in the trough in which they are washed; the lighter and more earthy run off with the water, but settle in the lool.

LOOM, the weaver's frame: a machine whereby several distinct threads are woven into one piece. Looms are of various structures, accommodated to the various kinds of materials to be woven, and the various manner of weaving them; viz, for woollens, silks, linens, cottons, cloths of gold; and other works, as tapestry, ribands, stockings, &c., divers of which will be found under their proper heads. See WEAVING. The weaver's loom-engine, otherwise called the Dutch loom-engine, was brought into use from Holland to London, in or about the year 1676.

The lower compartment of pl. 100 represents a loom for weaving silks or other plain work. A, fig. 6, is a roll called the cloth-beam, on which the cloth is wound as it is wove; at one end it has a racket-wheel a, and a click to prevent its running back; at the same end it has also four holes in it, and is turned by putting a stick in these holes; at the other end of the loom is another roll B, on which the yarn is wound; this has two small cords bb wrapped round it, the ends of which are attached to a bar d, which has a weight D hung to it; by this means a friction is caused, which prevents the roll B turning by accident. EF are called lambs; they are composed of two sticks efhi, between which are fastened a great number of threads; to the bar e are fastened two cords gh, which pass over pulleys, and are fastened to the bar h of the lamb F; the lower bars of each lamb are connected by cords with the treadles GH; the workman sits on the seat K, and places his feet upon these treadles; as they are connected together by the cords gh, when he presses down one, it will raise the other, and the lambs with them; a great number of threads, according to the width of the cloth, re wound round the yarn-beam B, and are

stretched to the cloth-beam A; the middle of the threads which compose the lamb EF, have loops (called eyes) in them, through which the threads between the rolls AB, which are called the warp, are passed; the first thread of the warp goes through the loops of the lambs E, the next attached to the lamb F, and so on alternately; by this means, when the weaver presses down one of the treadles with his foot, and raises the other, one lamb draws up every other thread, and the other sinks all the rest, so as to make an opening between the sets of thread. LL is a frame moving on a centre at the top of the frame of the loom; the lower part of this frame is shown in fig. 8. LL are the two uprights of the frame, I is the bar that connects them. Mis a frame carrying a great number of pieces of split reed, or sometimes fine wire, at equal distances; between these the threads of the warp are passed; the frame M is supported by a piece of wood m called the shuttle-race, which is fastened into the front of the pieces LL; each end of this piece has boards nailed to the sides, so as to form troughs NO; at a small distance above these are fixed two very smooth wires no; their use is to guide the two pieces pq, called peckers or drivers; to each of these pieces a string is fastened, and these strings are tied to a piece of wood P, which the weaver holds in his hand, and by snatching the stick to either side, draws the pecker forwards very quick, and gives the shuttle, fig. 7 (which is to be kaid in the trough before the pecker) a smart blow, and drives it along across the racem into the other trough, where it pushes the pecker along to the end of the wire ready for the next stroke, which throws it back again, and so on. Fig. 7 represents the under side of the shuttle on a larger scale: its ends are pointed with iron; it has a large mortise through the middle of it, in which is placed a quill a containing the yarn; b is a piece of glass, called the eye of the shuttle, with a hole in it, through which comes the end of the thread; dd are two small wheels to make it run easily on the race. The operations are as follow: The workman, sitting upon the seat K, holds the stick P in his right hand, and takes hold of one of the bars of the frame LL with his left; presses his foot on one of the treadles GH, which by means of the lambs EF, as before described, divides the warp; he then snatches the stick P, and by that means throws the shuttle, fig. 7, which unwinds the thread in it, and leaves it lying in between the threads of the warp; he then relieves the treadle he before kept down, and presses down the other: while he is doing this, he with his left hand draws the frame LL towards him, and then returns it. The use of this is to beat the last thread thrown by the shuttle close up to the one that was thrown before it by the split reeds M, fig. 8. As soon as he has brought the frame LL back to its original position, and again divided the warp by the treadle, he throws the shuttle again: when he has in this manner finished about 12 or 14 inches of cloth, he winds it up by turning the roll A with the stick, as before described. Some very expert weavers