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pointed lancet, for making incisions; and two fleams, one sharp and the other broadpointed. These last are somewhat like the point of a lancet, fixed in a flat handle, only no longer than is just necessary to open the vein.

FLEECE, the covering of wool, shorn off the bodies of sheep. See WOOL.

FLEECY hosiery, a very useful kind of manufacture of late invention, in which fine fleeces of wool are interwoven into a cotton piece of the common stocking texture: the nature of the manufacture is thus described, having in the common stocking frame, twitted silk, cotton-yarn, &c. begin the work in the common way of making ho siery, and having worked one or more course or courses in the usual method, begin to add a coating thus: draw the frame over the arch, and then hang wool or jersey, raw or unspun, upon the beards of the needles, and slide the same off their beards upon their stems, till it comes exactly, under the nibs of the sinkers; then sink the jacks and sinkers, and bring forward the frame, till the wool or jersey is drawn under the beards of the needles; and having done this, draw the frame over the arch, and place a thread of spun materials upon the needles, and proceed in finishing the course in the usual way of manufacturing hosiery with spun materials. Any thing manufactured in this way has, on the one side, the appearance of common hosiery, and on the other side the appearance of raw wool.

FLEET, commonly implies a company of ships of war, belonging to any prince or state: but sometimes it denotes any number of trading ships, employed in any particular branch of commerce.

In sailing, a fleet of men of war is usually divided into three squadrons; the admiral's, the vice-admiral's, and the rear-admiral's squadron; all which, being distinguished by their flags and pendants, are to put themselves, and, as near as may be, to keep themselves in their customary places, viz. The admiral, with his squadron, to sail in the van, that so he may lead the way to all the rest in the day-time, by the sight of his flag in the main-top-mast-head; and in the night-time, by his lights or lanterns. The vice-admiral and his squadron, is to sail in the centre, or middle of the fleet, the rear admiral, and the ships of his squadron, to bring up the rear. But sometimes other divisions are made, and those composed of the lighter ships and best sailors, are placed as wings to the van, centre, and rear, Merchant-fleets generally take their de

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nomination from the place they are bound to, as the Turkey fleet, East India fleet, &c. These, in time of peace, go in fleets for their mutual aid and assistance; in time of war, besides this security, they likewise procure convoys of men of war, either to escort them to the places whither they are bound, or only a part of the way, to a certain place or latitude, beyond which they are judged out of danger of privateers, &c. See CONVOY. FLESH. See ANATOMY.

FLEXION, in anatomy, is applied to the motion by which the arm or any other member of the body is bent. It is also applied to the muscles, nerves, &c.

FLEXION, or flexure of curves. See FLEXURE.

FLEXOR, in anatomy, a name applied to several muscles, which are so called from their office, which is to bend the part to which they belong, in opposition to the extensors, which open or stretch them. See ANATOMY.

FLEXURE of curves, in the higher geometry, is used to signify that a curve is both concave and convex, with respect to a given right line or a fixed point.

FLIGHT, in law. On an indictment of treason, felony, or even petit-larceny, if the jury find that the party fled for it, he shall forfeit his goods and chattels, though he is acquitted of the offence; but the jury seldom find the flight, it being thought too severe a punishment for that to which a man is prompted by his natural love of liberty.

FLINT. A semitransparent hard stone, of the siliceous order, of a greyish, black, or yellowish colour, well known for its general utility in giving fire with the steel. It is commonly found in nodules, in beds of chalk or sand, and frequently exhibits indications of its having been in a soft state. Some specimens are hollow, and internally lined with siliceous crystals. By long exposure on the surface of the ground, they gradually become white on their upper surface first, and afterwards all over. This whiteness, in process of time, penetrates into the substance of the flint, forming a crust sometimes one-twentieth of an inch thick, which may be scraped with a knife. It has been said, that this is a conversion of flint into calcareous earth; but we know of no proof of the fact; and as this white matter does not appear to be affected by nitric acid, we are inclined to think, that the flint is merely shattered by the weather in a manner somewhat analogous to the effect of ignition and quenching in water, which renders it white and friable.

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Weigleb found the common flint to con tain 80 parts in the 100 silex, 18 alumina, and 2 lime. It is used in making glass and pottery.

A solution of siliceous earth, made by fusing flints with a large proportion of fixed alkali, and dissolving the mass in water, is called liquor of flints.

FLOAT of a fishing-line, the cork or quill that floats or swims above water. See. ANGLING.

FLOAT also signifies a certain quantity of timber bound together with rafters, athwart, and put into a river to be conveyed down the stream; and even, sometimes, to carry burdens down a river with the stream.

FLOAT boards, those boards fixed to water-wheels of under-shot mills, serving to receive the impulse of the stream, whereby the wheel is carried round. See MILL.

FLOATING bodies are those which swim on the surface of a fluid, the most interesting of which are ships and vessels employed in war and commerce. It is known to every seaman, of what vast moment it is to ascertain the stability of such vessels, and the positions they assume when they float freely on the surface of the water. To be able to accomplish this, it is necessary to understand the principles on which that stability and these positions depend. A floating body is pressed downwards by its own weight in a vertical line passing through its centre of gravity; and it is supported by the upward pressure of a fluid, which acts in a vertical line that passes through the centre of gravity of the part which is under the water; and without a coincidence between these two lines, in such a manner as that both centres of gravity may be in the same vertical line, the solid will turn on an axis, till it gains a position in which the equilibrium of floating will be permanent. From this it is obviously necessary to find what proportion the part immersed bears to the whole, to do which the specific gravity of the floating body must be known, after which it must be found by geometrical method, in what positions the solid can be placed on the surface of the fluid, so that both centres of gravity may be in the same vertical line, when any given part of the solid is immersed under the surface. These things being determined, something is still wanting, for positions may be assumed in which the circumstances now mentioned concur; and yet the solid will assume some other position wherein it will permanently float. However operose and difficult (says

an able mechanic) the calculations necessary to determine the stability of nautical vessels may, in some cases be, yet they all depend upon the four following simple and obvious theorems, accompanied with other well known stereometrical and statical principles.

Theorem 1. Every floating bly displaces a quantity of the fluid in which it floats, equal to its own weight; and consequently, the specific gravity of the fluid will be to that of the floating body, as the magnitude of the whole is to that of the part immersed.

Theorem 2. Every floating body is impelled downward by its own essential power, acting in the direction of a vertical line passing through the centre of gravity of the whole; and is impelled upward by the re-action of the fluid which supports it, acting in the direction of a vertical line passing through the centre of gravity of the part immersed; therefore, unless these two lines are coincident, the floating body thus impelled must revolve round an axis, either in motion or at rest, until the equilibrium is restored.

Theorem 3. If by any power whatever a vessel be deflected from an upright position, the perpendicular distance between two vertical lines passing through the cen tres of gravity of the whole, and of the part immersed respectively, will be as the stability of the vessel, and which will be positive, nothing, or negative, according as the metacentre is above, coincident with, or below the centre of gravity of the vessel.

Theorem 4. The common centre of gravity of any system of bodies being given in position, if any one of these bodies be moved from one part of the system to another, the corresponding motion of the common centre of gravity, estimated in any given direction, will be to that of the aforesaid body, estimated in the same direction, as the weight of the body moved is to that of the whole system. From whence it is evident, that in order to ascertain the stability of any vessel, the position of the centres of gravity of the whole, and of that part immersed, must be determined; with which, and the dimensions of the vessel, the line of floatation, and angle of deflection, the stability or power either to right itself or overturn, may be found.

FLOOD, among seamen, is when the tide begins to come up, or the water begins to rise, then they call it young flood; after

which it is a quarter flood, half flood, and quire a prodigious time to complete them. high flood. See TIDE.

FLOOD mark, the mark which the sea makes on the shore, at flowing water, and the highest tide it is also called highwater-mark.

FLOOR. The lower part of a mine is called the floor, and the upper the roof, FLORENTINE work. When Italy, many years past, enjoyed a state of perfect tranquillity, and the minds of all ranks of the inhabitants were under the influence of religious enthusiasm, the different orders of religious, the priests, and the nobles, each endeavoured to excel the other in the splendid, decorations of churches, altars, and shrines; the arts of the architect, the sculptor, and the painter were exhausted, and the pious almost at a loss how to dispose of their riches in honour of their numerous patron saints. Mosaic work had been invented many centuries, but some ingenious person, disdaining the comparative case of that beautiful and expensive manner of imitating paintings, thought of Florentine work, which is performed by inserting fragments of precious stones in cement, so as to represent any subject usually treated by the pencil.

Keysler mentions a Carthusian monastery, situated between Milan and Pavia, of uncommon magnificence: "the greatest part of the altars in the church, are adorned with elegant representations of birds, flowers, &c. in the Florentine manner, performed by the artful position of precious stones inlaid in the marble. The convent entertains two excellent artists, a father and son, to perform these elegant works. The son, Valieri Sac, is so eminent in these performances, that the greatest mistress of embroidery would find it difficult to equal with her needle and silk, the variety of colours and shades which he expresses by sparks of agate, ruby, amethyst, cornelian, jasper, lapis-lazuli, and other precious stones. The high altar-piece, together with the tables on each side, are entirely of this Florentine work."

The Fabrica Degli Uffici, erected at Florence by Cosmo I., was appropriated in part for the reception of various artists, who worked exclusively for the Grand Duke, "But among all the performances executed here," says Keysler, "that styled Florentine work is the most elegant; sparks of precious stones, and particles of elegant marble, are so disposed as to represent the objects of nature in a very beautiful and surprising manner; but works of this kind re

A flower-piece lately finished, about a foot and a half in length, and half a foot in breadth, employed the artist above eighteen months; and a piece of embossed work, about the size of a common sheet of paper, representing the adoration of the Eastern magi, and a group of angels in the air, has already been forty years in hand, and under the direction of several masters."

The late unhappy state of Italy, and the probability of still further changes, has been so fatally destructive of the arts, that Florentine work will not soon be encouraged; and there is little doubt this laborious art will be almost lost.

FLORIN is sometimes used for a coin, and sometimes for a money of account. See COIN.

FLORY, FLOWRY, or FLEURY, in heraldry, a cross that has the flowers at the end circumflex and turning down, differing from the potence, inasmuch as the latter stretches out more like that which is called patee.

FLOTILLA, a name given to a number of ships which get before the rest in their return, and give information of the depar ture and cargo of the flota and galleons.

FLOUR, the meal of wheat-corn, finely ground and sifted. Flour, when carefully analyzed, is found to be composed, 1, of fecula, which is insoluble in cold water, but soluble in hot water; 2, of gluten; 3, of a saccharine matter, susceptible of the spiritnons fermentation.

FLOWER, in botany. By this term, former botanists, as Ray and Tournefort, &c., evidently meant the petals, or beautiful coloured leaves of the plant, which generally adhere to the seed-bud, or rudiment of the fruit. Since the introduction of the sexual method, the petals have lost their importance, and are now only considered as a finer sort of cover, which is generally present, but not essentially necessary to the existence of a flower, A flower then, in modern botany, is as different in meaning from the same term in former writers, as from the vulgar acceptations of the word at this day. The petals, the calyx, nay, the threads or filaments of the stamina may all be wanting, yet it is a flower still, provided the anthers, or male organ; and the stigma or summit of the style, the female organ, can be traced; and that either immediately in the neighbourhood of one another, as in most plants; on different parts of the same plant, as in the class Monoecia or on different plants raised from the same

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seed, as in the class Dioecia. In this manner is to be understood the general principle with which the sexual method sets out, that every vegetable is furnished with flower and fruit. The essence of the flower, therefore, consists in the anthers and stigma, which constitute a flower, whether the covers, that is, the calyx and petals, are present or not.

FLOWER de luce. See IRIS.

FLOWER de lis, or FLOWER de luce, in heraldry, a bearing representing the lily, called the queen of flowers, and the true hieroglyphic of royal majesty; but of late it is become more common, being borne in some coats one, in others three, in others five, and in some semee, or spread all over the escutcheon in great numbers.

FLOWERS, in chemistry, a term formerly applied to a variety of substances procured by sublimation, and were in the form of slightly cohering powder: hence, in all old books, we find mention made of the flowers of antimony, arsenic, zinc, and bismuth, which are the sublimed oxides of these metals, either pure, or combined with a small quantity of sulphur: we have also still in use, though not generally, the terms flowers of sulphur, benzoin, &c.

FLUATES, in chemistry, salts of which the FLUORIC ACID (which see) is the chief ingredient. Finor spar, denominated fluate of lime, which is found in great plenty in many countries, and is very abundant in Derbyshire, where it obtains the name of Derbyshire spar, is the most important among the fluates. The chief properties of these salts are, 1. When sulphuric acid is poured upon them, they emit acrid vapours of fluoric acid, which corrode glass. 2. When heated, several of them phosphoresce. 3. They are not decomposed by heat, nor altered by combustibles. 4, They combine with silica by means of heat.

FLUENT, in fluxions, the flowing quantity, or that which is continually either increasing or decreasing, whether line, surface, solid, &c. See FLUXION.

FLUID, in physiology, an appellation given to all bodies whose particles easily yield to the least partial pressure or force impressed.

All fluids, except those in the form of air or gas, are incompressible in any considerable degree. The Academy del Cimento, from the following experiment, supposed water to be totally incompressible. A globe made of gold, which is less porous than any other metal, was completely filled with water

and then closed up; it was afterwards placed under a great compressive force, which pressed the fluid through the pores of the metal, and formed a dew all over its surface, before any indent could be made in the vessel. Now, as the surface of a sphere will contain a greater quantity than the same surface under any other form whatever, the academy supposed that the compressive power which was applied to the globe must either force the particles of the fluid into closer adhesion, or drive them through the sides of the vessel before any impression could be made on its surface; for although the latter effect took place it furnishes no proof of the incompressibility of water, as the Florentines had no method of determining that the alteration of figure in their globe of gold occasioned such a diminution of its internal capacity, as was exactly equal to the quantity of water for`ced into its pores; but this experiment serves to shew the great minuteness of the particles of a fluid in penetrating the pores of gold, which is the densest of all metals. Mr. Canton brought the question of incompressibility to a more decisive determination. He procured a glass-tube, of about two feet long, with a ball at one end, of an inch and a quarter in diameter: having filled the ball and part of the tube with mercury, and brought it to the heat of 50° of Farenheit's thermometer, he marked the place where the mercury stood, and then raised the mercury by heat to the top of the tube, and there sealed the tube, hermetrically; then upon reducing the mercury to the same degree of heat as before, it stood in the tube of an inch higher than the mark. The same experiment was repeated with water, exhausted of air, instead of mercury, and the water stood in the tube above the mark. Now, since the weight of the atmosphere on the outside of the ball, without any counterbalance from within, will compress the ball, and equally raise both the mercury and water; it appears that the water expands of an inch more than the mercury, by removing the weight of the atmosphere. From this, and other experiments, he infers, that water is not only compressible but elastic; and that it is more capable of compressibility in winter than in summer.

All fluids gravitate, or weigh, in proportion to their quantity of matter, not only in the open air, or in vacuo, but in their own elements. Although this law seems so consonant to reason, it has been supposed by

ancient naturalists, who were ignorant of the equal and general pressure of all fluids, that the component parts, or the particles of the same element, did not gravitate or rest on each other; so that the weight of a vessel of water, balanced in air, would be entirely lost when the fluid was weighed in its own element. The following experiment seems to leave this question perfectly decided: take a common bottle, corked close, with some shot in the inside to make it sink, and fasten it to the end of a scale beam; then immerse the bottle in water, and balance the weight in the opposite scale; afterwards open the neck of the bottle and let it fill with water, which will cause it to sink; then weigh the bottle again. Now it will be found that the weight of the water which is contained in the bottle is equal to the difference of the weights in the scale, when it is balanced in air; which sufficiently shews that the weight of the water is the same in both situations. As the particles of fluids possess weight as a common property of bodies, it seems reasonable that they should possess the consequent power of gravitation which belongs to bodies in general. Therefore, supposing that the particles which compose fluids be equal, their gravitation must likewise be equal; so that, in the descent of fluids, when the particles are stopped and supported, the gravitation being equal, one particle will not have more propensity than another to change its situation, and after the im、 pelling force has subsided the particles will remain at absolute rest.

From the gravity of fluids arises their pressure, which is always proportioned to the gravity. For if the particles of fluids have equal magnitude and weight, the gravity or pressure must be proportional to the depth, and equal in every horizontal line of fluid; consequently, the pressure on the bottom of vessels is equal in every part. The pressure of fluids upwards is equal to the pressure downwards at any given depth. For, suppose a column of water to consist of any given number of particles acting upon each other in a perpendicular direction, the first particle acts upon the second with its own weight only; and, as the second is stationary, or fixed by the surrounding particle, according to the third law of motion, that action and reaction are equal; it is evident that the action or gravity in the first is repelled in an equal degree by the reaction of the second; and in like planner, the second acts on the third, with

its own gravity added to that of the first, but still the reaction increases in an equivalent degree, and so on throughout the whole depth of the fluid.

The particles of a fluid, at the same depth, press each other equally in all directions. This appears to rise out of the very nature of fluids, for as the particles give way to every impressive force, if the pressure amongst themselves should be unequal the fluid could never be at rest, which is contrary to experience; therefore, we conclude, that the particles press each other equally, which keeps them in their own places. This principle applies to the whole of a fluid as well as a part. For if four or five glass tubes, of different forms, be immersed in water, when the corks in the ends are taken out, the water will flow through the various windings of the different tubes, and rise in all of them to the same height as it stands in the straight tube: therefore the drops of fluids must be equally pressed in all directions during their ascent through the various angles of the tube, otherwise the fluid could not rise to the same height in them all.

From the mutual pressure and equal action of the particles of fluids, the surface will be perfectly smooth and parallel to the horizon. If from any exterior cause the surface of water has some parts higher than the rest, these will sink down by the natural force of their own gravitation, and dif fuse themselves into an even surface. See HYDROSTATICS.

FLUIDS, motion of. The motion of fluids, viz. their descent or rise below or above the common surface or level of the source or fountain, is caused either, 1. By the natural gravity or pressure of the fluid contained in the reservoir, or fountain; or, 2. By the pressure or weight of the air on the surface of the fluid in the reservoir, when it is at the same time either taken off or diminished on some part in aqueducts, or pipes of conduit. 3. By the spring or elastic power of compressed or condensed air, as in the common water engine. 4. By the force of pistons, as in all kinds of forcing pumps, &c. 5. By the power of attrac tion, as in the case of tides, &c.

FLUIDITY. The state of bodies when their parts are very readily moveable in all directions with respect to each other. Many useful and curious properties arise out of this modification of matter, which form the basis of the mechanical science called hydrostatics, and are of considerable impor

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