bridge, or cock, screwed upon the same part of the rod, but omitted in the figure, to show the mechanism: g, g, are two screws entering at the edges, and reaching into the cavity near the centre of the ball. The ends of the screws next the centre are turned into the form seen in the figure, which, pressing with the weight of the ball against the longer arms of the levers, cause the short ends to press against the brass bar at b. Let us now suppose that the rod of the pendulum, and the brass annexed to it, grow longer by heat, and that the brass lengthens more than the iron of the same length; then the brass, by the excess of its dilation, will press the short ends of the levers downwards at b, and at the same time necessarily lit up the ball, which rests on the long ends of the same lever, at fƒ, to any proportion necessary for due compensations. The calculated proportion of the short arms of the levers must be to the long ones as the excess in the expansion of brass is to that of the whole length of iron; and, if this calculation be found on trial not perfectly accurate, the side screws g, g, will produce the exact compensation at a few adjustments. At ik, the inferior end of the iron verge, a strong double spring is fixed to bear the major part of the ball's weight, by its pressure upwards against two points of the ball, equidistant from the vertical line. This is the description of the first pendulum made in this way; and the only alteration that the inventor made afterwards was placing the side screws in the body of the ball. Cumming proposes, in his Elements of Clock and Watch-work, that the. brass bar should elongate between two iron bars, in order to keep it straight, and to prevent the jerks to which he conceives the foregoing construction liable: he proposes also to alter the structure of the short arms of the levers, by making them turn each on an axis of motion, and to change their places of pressure mutually, in order that their united action may be applied in the same point, at the centre of the brass bar, in direct opposition to the line of downward expansion. See his Elements, p. 106, and plate xi. Mr. Hardy of Clerkenwell has also improved considerably Elliott's pendulum. Mr. Troughton's mercurial pendulum.-This is an improvement on Graham's mercurial pendulum. About the year 1790 Mr. Edward Troughton, with a view of doing away the most material prejudice against this useful instrument, contrived a modification of the mercurial pendulum, which must be considered as a distinct invention; the materials being differently arranged both as to quality, quantity, and situation. The prejudice alluded to was that the metallic rod of Graham, and the vessel of mercury, would not be affected by changes of temperature in a contemporaneous manner, but that the mercury being below the rod, and having on that account a quicker motion, would cool sooner than the metallic rod, and be liable to more frequent changes from its greater susceptibility. Mr. Troughton therefore substituted a strong glass tube with a bulb at the lower extremity, to be filled to a certain height with mercury, which should rise and fall precisely as in a thermomewhich instrument, in fact, his tube is; and, to make it useful as such, it carries a graduated scale. The tube in question is about the size of a barometer tube, and the bulb large enough to contain forty-five ounces of pure mercury by the aid of one-balf the tube. Fig. 2 of plate II. exhibits Mr. Troughton's arrangement. A B is the mercurial rod filled with mercury to the middle point of the 10d; CD the bulb guarded by the surrounding lenticular bob of brass and lead made in the usual way, except that it is hollow in the centre: the metallic parts of the pendulum weigh about nine pounds exclusively of the mercury; the rim that surrounds the bulb, and by which the weight of the lenticular bob is supported, projects into two notches cut in the interior edges of the metallic lens, at each side of the cavity, and the nice fitting of the bulb to its rim renders the glass capable of bearing the weight of metal supported by it. The compensation of this pendulum is effected entirely by the ascent and descent, alternately, of the mercury up and down the glass tube as the heat varies; and as the expansion of glass varies much less than that of any of the metals, the small column of mercury contained in the tube is found sufficient to answer its purpose completely after a trial of more than twenty years. Ward's compensation pendulum.-This is an invention of Mr. Henry Ward, of Blandford in Dorsetshire, who, in March 1806, communicated it to the Society of Arts, accompanied by a model, which gained him the silver medal of the society. It consists of three bars, two of iron and one of zinc, arranged in a manner very similar to Deparcieux's improvement of Regnauld's old French pendulum, but without the adjustment lever. The instrument appears in fig. 3, plate II., where hh and ii are two flat rods of iron or steel, about half an inch wide and an eighth of an inch thick each; and k k is a rod of zinc, of nearly a quarter of an inch thick, interposed; the two extreme or iron rods are cranked, one at the top to receive the suspension spring, and the other at the bottom to hold the ball in the same vertiçal line with the zinc rod. These three parallel rods are united by four screws, l,l,l, l, which, passing through oblong holes in the bars h h and kk, screw into the rod ii, while the rod hh is fastened to the zinc one kk, by the single screw m near its lower extremity, which screw is the screw of adjustment for temperature, and requires several holes to be made in the bar hh, and also in k k, that the length of the zinc bar may be limited to its due proportion for exact compensation. The iron bar ii rests by a chinpiece on the upper end of the zinc bar, and therefore the ball supported by its lower tapped end stretches all the bars equally. If the zinc bar had rested on the crank at the bottom of the bar hh, instead of being held by the screw m, the arrangement would have been the same as in Deparcieux's, but with zinc substituted for brass, which consequently does not require the aid of a lever to increase its effect. The proportional expansions of zinc and iron were taken for this pendulum from Smeaton's table in the fortyeighth volume of the Phil. Trans. of London, and were made for hammered zinc as 373: 151; but subsequent observations on the rate of the clock, to which the pendulum was applied, proved that the expansion of the hammered zinc was greater than Smeaton's table gives it, though the quantity was within the reach of the adjustment. Reid's compensation pendulum.-Another compensation pendulum by Mr. Adam Reid of Woolwich was also presented to the Society of Arts in April 1809, and the inventor was rewarded with fifteen guineas for his contrivance. This is given in fig. 4, plate II., and has its compensation of a tube of zinc acting on the ball from the lower end of the steel verge thus: A B is the steel verge, made a little thicker where it enters the ball C, and also of a lozenge shape, to prevent the ball's turning, but above and below it is cylindrical; near the centre of the ball is a shoulder in the verge, against which the upper end of the zinc tube D presses the cross piece of the ball when the nut E is turned up close to its lower extremity, but when the nut is turned back, in adjusting for rate, the tube descends a little, and the ball with it, while it rests on the upper extremity of the tube. When the compensation is too much the tube may be shortened till it is found of the exact length, by a trial of the rate in extremes of temperature. In the figure the length of the zinc tube does not appear sufficiently long to compensate an entire verge of steel. The inventor observes that platina might be substituted for steel, and steel for zinc, for the formation of this kind of pendulum, but that the expense would be enhanced by the dearness of platina. Ritchie's and Nicholson's compensation pendulum.-In March 1812 Mr. David Ritchie, of Clerkenwell, laid before the society a model of a compensation pendulum, for which he received twenty guineas. The compensation was effected by the flexure of two compound horizontal bars interposed between the verge and the ball, which act on the same principle as the compound bars in the ordinary compensation balances of a chronometer. Fig. 5 represents the pendulum, in which A is the spring of suspension, B the ball, and C the steel verge as usual, with the nut of adjustment for rate at E, below the ball. The compensating bars are F and G, the upper part of F and the lower part of G being steel, and the other parts brass; so that any additional heat may bring the bars nearer together by the convexity of the brass faces of the compound bars being contiguous.. These compound bars have each a sliding piece above and below, and frespectively, by the sliding of which the bars may have their effective lengths altered, in the adjustment for temperature; and are connected by the slender springs e and f, which bear a portion of the ball's weight; the remainder being borne by the springs and m attached by screws at h, one to the verge piece d and the other to the ball piece b, while they themselves are united by screws at and m. The compensation frame, so constructed, is adjusted by sliding the compound bars, before they are fixed, till the centre of the ball falls in the vertical line of the verge, where the screws at h fix it for trial. It has been feared that when the crutch of the clock urges the verge the ball will not move with it till the springs e and fare bent a little; for when the ball is heavy, as is now customary in seconds' pendulums, its weight will place a great stress on the slender springs that connect it with the verge, and produce, probably, a vacillation, as in Doughty's, that must be very unfavorable to isochronism, allowing even that the compensation is perfect. To avoid this evil Mr. Nicholson placed a similar compensation bar on the cock of suspension above the verge of his pendulum, and also above the cock of limitation, as seen in fig. 6, but without any spring, and in this situation the varying curvature of the hori zontal compound bar, E E, altering the length of the suspension spring, produced the alternate rising and falling of the ball, as the verge carried it in an opposite direction, so that the centre of oscillation was comparatively stationary. Sec Phil. Journal, vol. i. 4to. ed., plate V. fig. 3. The same author also contrived a compensation pendulum composed of four rods of steel and one of a compound, or alloy, of zinc and silver, which is described in vol. ii. of his 4to. Phil: Journal, p. 205, plate IX. PENELOPE, in fabulous history, the daughter of Icarus, who married Ulysses, by whom she had Telemachus. During the absence of Ulysses, who was gone to the siege of Troy, and who staid twenty years from his dominions, several princes, charmed with Penelope's beauty, told her that Ulysses was dead, offered to marry her, and pressed her to declare in their favor. She promised compliance on condition they would give her time to finish a piece of tapestry she was weaving; but at the same time she undid in the night what she had done in the day, and thus eluded their importunity until Ulysses's return. PENELOPE, in ornithology, a genus of birds of the order of gallinæ, the characters of which are these: The beak is bare at the base; the head is covered with feathers; the neck is quite bare; the tail consists of twelve principal feathers; and the feet are for the most part bare. Linné, in his Systema Naturæ, enumerates six species. 1. P. crax cumanensis, called by Latham, &c., yacou. It is bigger than a common fowl. The bill is black; the head feathers are long, pointed, and form a crest, which can be erected at pleasure. The irides are of a pale rufous color; the space round the eye is naked, similar to that of a turkey. It has also a naked membrane or kind of wattle, of a dull black color. The blue skin comes forward on the bill, but is not liable to change color like that of the turkey. The plumage has not much variation; it is chiefly brown, with some white markings on the neck, breast, wing coverts, and belly; the tail is composed of twelve feathers, pretty long, and even at the end; the legs are red. This species inhabits Cayenne, but is a very rare bird, being met with only in the inner parts, or about the Amazons country, though in much greater plenty up the river Oyapoc, especially towards Camoupi; and indeed those which are seen at Cayenne are mostly tame ones; for it is a familiar bird, and will breed in that state, and mix with other poultry. It makes the nest on the ground, and hatches the young there, but is at other times mostly seen on trees. It frequently erects the crest, when pleased or taken notice of, and likewise spreads the tail upright like a fan, in the manner of the turkey. It has two kinds of cry; one like that of a young turkey, the other lower and more plaintive; the first of these is thought by the Indians to express the word couyovoit, the other yacou. 2. P. maralia, the marail, about the size of a fowl, and shaped somewhat like it. The bill and irides are blackish; the space round the eye is bare, and of a pale red; the chin, throat, and fore part of the neck are scarcely covered with feathers; but the throat itself is bare, and the membrane elongated to half an inch or more; both this and the skin round the eyes change color, and become deeper and thicker when the bird is irritated. The head feathers are longish, so as to appear like a crest when raised up, which the bird often does when agitated; at which time it also erects those of the whole body; and so disfigures itself as to be scarcely known. The general color of the plumage is a greenish black; the fore part of the neck is tipped with white; the wings are short; the tail is long, consisting of twelve feathers, which are even at the end, and commonly pendent, but can be lifted up, and spread out like that of the turkey; the legs and toes are of a bright red; the claws are crooked, and somewhat sharp. In a collection, says Latham, from Cayenne was a bird, I believe, of this very species. It was twenty-eight inches long; the bill is like that of a fowl, brown, and rather hooked; round the eyes bare; the head is crested; the feathers of the fore part of the neck are tipped with white; the breast and belly are rufous brown; the rest of the plumage is greenish brown; the tail is eleven inches long, and rounded at the end; the quills just reach beyond the rump; the legs are brown, and the claws hooked. This species is common in the woods of Guiana, at a distance from the sea, though it is less known than could be imagined; and generally found in small flocks, except in breeding time, when it is only seen by pairs, and then frequently on the ground, or on low shrubs; at other times on high trees, where it roosts at night. The female makes her nest on some low bushy trees as near the trunk as possible, and lays three or four eggs. When the young are hatched, they descend with their mother, after ten or twelve days. The mother acts as other fowls, scratching on the ground like a hen, and brooding the young, which quit their nurse the moment they can shift for themselves. They have two broods in a year; one in December or January, the other in May or June. The best time of finding these birds is morning or evening, being then met with on such high trees whose fruit they feed on, and are discovered by some of it falling to the ground. The young birds are easily tamed, and seldom forsake the places where they have been brought up: they need not be housed, as they prefer the roosting on tall trees to any other place. Their cry is inharmonious, except when irritated or wounded, when it is harsh and loud. Their flesh is much esteemed. Buffon supposes this bird to be the female of the yacou, or at least a variety; but that this cannot be, the anatomical inspection will at once determine. The windpipe of this bird has a singular construction, passing along the neck to the entrance of the breast, where it arises on the outside of the flesh, and after going a little way downwards, returns, and, then passes into the cavity of the lungs. It is kept in its place on the outside by a muscular ligament, which is perceivable quite to the breast bone. This is found to be the case in both male and female, and plainly proves that it differs from the yacou, whose wind-pipe has no such circumvolution in either sex. If this be the bird mentioned by Fermin, in his History of Guiana, p. 176, he says that the crest is cuneiform, and of a black and white color; and observes that they are scarce at Surinam; but it does not seem quite certain whether he means this species or the yacou. Bancroft mentions a bird of Guiana by the name of marrodée, which he says is wholly of a brownish-black: the bill the same; and the legs gray. These he says are common, and make a noise not unlike the name given it, perching on trees. The Indians imitate their cry so exactly as to lead to the discovery of the place the birds are in, by their answering it. The flesh of them is like that of a fowl: it is therefore most likely the marail. 3. P. meleagris cristata, called by Ray penelope jacupeme, and by Edwards the guan, or quan, is about the size of a fowl, being about two feet six inches long. The bill is two inches long, and of a black color; the irides are of a dirty orange color; the sides of the head are covered with a naked purplish blue skin, in which the eyes are placed beneath the throat, for an inch and a half, the skin is loose, of a fine red color, and covered only with a few hairs. The top of the head is furnished with long feathers, which the bird can erect as a crest at pleasure; the general color of the plumage is brownish black, glossed over with copper in some lights; but the wing coverts have a greenish and violet gloss. The quills mostly incline to a purple color; the fore part of the neck, breast, and belly, are marked with white spots; the thighs, under tail coverts, and the tail itself, are brownish black; the legs are red; the claws black. Some of these birds have little or no crest, and are thence supposed to be females. They inhabit Brasil and Guiana, where they are often made tame. They frequently make a noise not unlike the word jacu. Their flesh is much esteemed. 4. P. meleagris satyra, the horned pheasant. Latham calls it the horned turkey. This species is larger than a fowl, and smaller than a turkey. The color of the bill is brown; the nostrils, forehead, and space round the eyes are covered with slender black hairy feathers; the top of the head is red. Behind each eye there is a fleshy callous blue substance like a horn, which tends backward. On the fore part of the neck and throat there is a loose flap of a fine blue color, marked with orange spots, the lower part of which is beset with a few hairs; down the middle it is somewhat looser than on the sides, being wrinkled. The breast and upper part of the back are of a full red color. The neck and breast are inclined to yellow. The other parts of the plumage and tail are of a rufous brown, marked all over with white spots, encompassed with black. The legs are somewhat white, and furnished with a spur behind each. A head of this bird, Mr. Latham tells us, was sent to Dr. Mead from Bengal, together with a drawing of the bird, which was called anpaul pheasant. It is a native of Bengal. 5. P. pipile, or crax pipile, black in the belly, and the back brown, stained with black The flesh on the neck is of a green color. It is about the bigness of the yacou, and has a hissing noise. The head is partly black and partly white, and is adorned with a short crest. The space about the eyes, which are black, is white; the feet are red. It inhabits Guiana. 6. P. vociferans, the vociferating penelope, The bill of this bird is of a greenish color: the back is brown, the breast green, and the belly is of a whitish brown. Latham calls it the crying curassaw. It is about the bigness of a crow. PENESTICA, a town of the Helvetii, between Lacus Lausonius and Salodurum; called Petenisca by Peutinger; thought now to be Biel, the capital of a small territory in Switzerland.-Antonine. Cluverius. PENETRALE, a sacred room or chapel in private houses, which was set apart for the worship of the household gods among the ancient Romans. In temples also there were penetralia, or apartments of distinguished sanctity, where the images of the gods were kept, and certain solemn ceremonies performed. PENETRATE, v. a. & v. n.) PENETRABLE, adj. PENETRABILITY, n. s. PEN'ETRAILS, PENETRANCY, Fr. penetrer, penetrable, penetrant of Lat. penetro. To pierce; enter PENETRANT, adj. a body; enter PENETRATION, n. s. beyond the PENETRATIVE, adj. surface: hence to affect the mind or feelings; to make way mentally or otherwise: penetrable is, susceptible of being pierced, or of mental impression; sympathetic penetrability, the corresponding nounsubstantive: penetrails, an obsolete word for the interior parts of the body: penetrant, having power to pierce or enter; sharp, subtle, prevailing penetrative is synonymous with penetrant: penetration, the act of entering a body; mental entrance, acuteness, or subtlety. Peace! And let me wring your heart, for so I shall, Wouldst thou see If we reach no farther than metaphor, we rather fancy than know, and are not yet penetrated Locke. into the inside and reality of the thing. The subtilty, activity, and penetrancy of its effluvia their way through all bodies. no obstacle can stop or repel, but they will make Ray evacuated into the intestines, where it is further subThe food, mingled with some dissolvent juices, is tilized and rendered so fluid and penetrant that the finer part finds its way in at the streight orifices of the lacteous veins. Id. Id. There shall we clearly see the uses of these things which here were too subtile for us to penetrating. Marrow is of all other oily substances, the most pe Arbuthnot on Aliments. netrate. There being no mean between penetrability and impenetrability, passivity and activity, they being contrary; therefore the infinite rarefaction of the one quality is the position of its contrary. Cheyne. Court virtues bear, like gems, the highest rate, Born where heaven's influence scarce can penetrate: Though the same sun with all diffusive rays Smile in the rose, and in the diamond blaze, We praise the stronger effort of his power, And always set the gem above the flower. O thou, whose penetrative wisdom found The south sea rocks and shelves, where thousands drowned. Swift's Miscellanies. netrails to insinuate some time must be allowed. The heart resists purulent fumes, into whose pe Pope. Harvey. very swiftly. Grew's Museum. The penguin is very common in the West Indies, where the juice of its fruit is often put into punch, being of a sharp acid flavour: there is also a wine made of the juice of this fruit, but it will not keep Miller. good long. PENGUIN, in botany (sect. I. Def. 2), or wild ananas, is a species of bromelia. See BROMELIA. PENICHE, a fortified town of Portugal, on a peninsula in the Atlantic, surrounded by rocks. It has a harbour defended by a fort. In 1589 this town was taken by the English under Sir Francis Drake. Inhabitants 2800. Forty-eight miles N. N. W. of Lisbon. Long. 9° 23′ 56" W., lat. 39° 21' 48" N. PENICILLUS, among surgeons, is used for a tent to be put into wounds or ulcers. PENIEL, or PENUEL, a city beyond Jordan, near the ford or brook Jabbok, where Jacob wrestled with an angel. See Gen. xxxii. 24, &c. The city built afterwards in this place was given to the tribe of Gad. Gideon, returning from the pursuit of the Midianites, overthrew the tower of Peniel (Judges viii. 17), and put all the men of the city to death, for having refused bread to him and his people, and having answered him in a very insulting manner. Jeroboam I. rebuilt Peniel (1 Kings xii. 25); and Josephus says that he built a palace in it. PENJINSKAJA, a gulf of Eastern Siberia, forming the northern part of the bay of Okhotsk. It extends a considerable distance inland, and receives the Penjine River. PENINGTON (Isaac), a celebrated English Quaker, born in 1617. He was an early convert of George Fox; and both preached and wrote in defence of his system. Under the persecuting spirit of that age, he was several times imprisoned, although he was of a meek, quiet, and philanthropic spirit, and very much beloved. He died at Goodnestone in Sussex in 1679. PENINNAH, the second wife of Elkanah, the father of Samuel. Her fertility, and Hannah's barrenness, are recorded in 1 Sam. i., with several interesting circumstances, which show the folly and inconvenience of polygamy. PENINSULA, n. s. Į Fr. peninsule; Lat. PENINSULATED, adj. pene insula. A piece of land almost surrounded by the sea. Aside of Milbrook lieth the peninsula of Inswork, on whose neckland standeth an ancient house. Carew. PENITENCE, n. s. Fr. penitence, peniPENITENT, adj. & n. s. tent, penitentiel, of PENITENTIAL, adj. & n.s. Lat. penitentia. PENITENTIARY, N.s. Repentance; conPENITENTLY, adj. trition; sorrow for sin; repentant course of action: penitent is, sorrowful for sin; reforming or reformed; a person thus sorrowful and reformed; also one under a course of church penance or censure: penitential is expressing penitence, or enjoined as a course of discipline for sin; also a book directing such a course penitentiary is, one who prescribes penitential rules; one who observes them; or a place where they are observed. His frown was full of terror, and his voice Shook the delinquent with such fits of awe As left him not, till penitence had won Lost favour back again, and closed the breach. Couper. PENITENCE is sometimes used for a state of repentance, and sometimes for the act of repenting. See REPENTANCE. It is also used for a discipline or punishment attending repentance, more usually called penance. It also gives title to several religious orders, consisting either of converted debauchees and reformed prostitutes, or of persons who devote themselves to the office of reclaiming them. Of this latter kind are these: PENITENCE OF ST. MAGDALEN, AT PARIS, CONGREGATION OF, owed its rise to the preaching of F. Tisseran, a Franciscan, who converted a number of courtezans about the year 1492. Louis, duke of Orleans, gave them his house for a monastery, or rather, as appears by their constitutions, Charles VIII. gave them the hotel called the Bochaigne, whence they were removed to St. George's chapel in 1572. By virtue of a brief of pope Alexander, Simon, bishop of Paris, in 1497, drew them up a body of statutes, and gave them the rule of St. Augustine. None were admitted who were above thirty-five years of age, and, till the beginning of the last century, none but penitents; but after its reformation by Mary Alvequin in 1616, none were admitted but maids, who, however, still retain the ancient name peni tents. PENITENCE OF ST. MAGDALEN, Order of, established about the year 1272 by one Bernard, a citizen of Marseilles, who devoted himself to the work of converting the courtezans of that city. Bernard was seconded by several others, who, forming a kind of society, were at length erected into a religious order by pope Nicholas III., under the rule of St. Augustine. F. Gesnay says, that they also made a religious order of the penitents, or women they converted, giving them the same rules and observances which they themselves kept. PENITENTS, an appellation given to certain fraternities of penitents, distinguished by the different shape and color of their habits. These are secular societies, who have their rules, statutes, |