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Entered, according to the Act of Congress, in the year 1832, by

In the Clerk's office of the District Court of the Eastern District of Pennsylvania.

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Per, Writing-Pers. It is well known year 1433, extremely rare in Venice. We that the ancients employed a certain reed, learn from the familiar letters of learned the nature of which is not precisely ascer men of that time, that they were equally tnined, for writing. The reeds were split, troubled by the rarity of quills and by the and shaped to a point like our quills. difficulty of making good ink. Of late, When goose-quills first came into use, or steel pens have been much used and imwho first borrowed from the emblem of proved, and for certain purposes, as for folly the instruments of wisdom, is not signing bank notes, to make the signatures known. It has been asserted, that quills uniform, they appear well adapted; as also were used for writing as early as the fifth for people who cannot make pens; but, century, according to the history of Con- on the whole, the quill affords a much stantius. The oldest certain account is a easier and handsomer chirography. passage of Isidore, who died 636 A. D., Penal Law. (See Criminal Law.) and who, among the instruments employ PENANCE; every penalty borne for the ed for writing, mentions reeds and feath- expiation of an offence. In the early ers. There exists, also, a poem on a pen, Christian church, this ancient judicial written in the same century, and to be principle was transferred to religious penfound in the works of Adhelm, the first ance, that is, to the atonement which the Saxon who wrote in Latin. Alcuin (q. v.), sinner has to make, for his trespasses, to the friend and teacher of Charlemagne, God and the church. According to the mentions writing-pens in the eighth cen

doctrine of the Protestants, it is not among tury. After that time, proofs exist which the sacraments.

This doctrine considers put the question of their use beyond dis- compunction and faith as the only elepute. Mabillon (q. v.) saw a manuscript ments of repentance and reformation. gospel of the ninth century, in wbich the Penance is considered by the Catholic evangelists were represented with pens in church a sacramental institution. The their hands. Calami properly signify the conditions for the necessary transition Teeds which the ancients used in writing. from bad to good, are a humble consciousModern authors often use the word as a ness of guilt. The conversion itself is a Latin term for pens, and it is probable change in the soul of man, effected by the that the same was employed to signify power of God, but necessarily connected quills before the time of Isidore. Reeds with an exterior alteration. The power were used for a considerable time after the of forgiving sins, in the literal sense of the introduction of writing-pens. In convents, word, say the Catholics, has been transthey were retained a long time for the ferred by Christ to the apostles, and to initials only. By some letters of Erasmus the church; but the latter can forgive the to Reuchlin, it appears that the former re- sins only of the truly repentant and conceived three reeds from the latter, and verted sinner. To bring him to the expressed a wish that Reuchlin, when he knowledge of himself, the church has procured more, would send some of them established confession; to calm his conto a certain learned man in England. science, absolution ; for the instruction Quills, for some reason, were, about the and discipline of the converted, she in


flicts penance, as a satisfaction to his head of a ship-of-war, and usually terown conscience and to God. Confession minating in two ends or points, called the was not invented by Innocent III, but swallow's-tail. It denotes that a vessel is only enjoined by him

at least once a year. in actual service.-Broad pendant is a It is followed by absolution, according to kind of flag terminating in one or two the authority transmitted to the church, points, used to distinguish the chief of a and by the imposition of such penances squadron.-Pendant is also a short piece as are necessary to free from 'the conse of rope, fixed on each side, under the quences of sin. The council of Trent shrouds, upon the heads of the main and declares, in sess, xiv, c. 8, that satisfaction fore masts. for sin is effected only by Christ, and it is PENDULUM, in dynamics, is a simple left for the individual to bring forth fruits ponderous body, so suspended by a flexiworthy of repentance. Days of penance ble cord from an axis of suspension, that and fasting are holy days, which, in certain it is at liberty to vibrate by the action of countries, are fixed annually, or after gen- its own gravity alone, when it is once eral calamities, for the purpose of a gene- raised, by any external force, to the right ral expression of penitence, or with the or left of its quiescent position; and, in view of appeasing the anger of the Deity. demonstrating the theory of its motion, The great day of fasting among the Jews mathematicians are obliged to assume, is the Long Night. The Christians imic that there is no rigidity in the cord, no tated these fast-days.

friction at the axis of suspension, no rePerates; the private or public gods sistance to motion made by the air

, and of the Romans; in the former sense, they no variation in the total length of the cord, resembled the Lares (7.v.), with whom they arising from the variable temperature or are often confounded. Not only every moisture of the atmosphere; and if these house, but every city, had its Penates, and assumptions were strictly correct, a penthe latter were the public gods. The dulum, once put in motion, would conmost celebrated at Rome were those that tinue to move, ad infinitum, without a protected the empire. These were brought further accession of any external force; into Italy by Æneas, together with Vesta but, when the pendulum is applied as the and her eternal fire. According to Varro regulator of a clock, for which purpose it and Macrobius, the Penates were rude im- is admirably adapted, the assuniptions ages of wood orstone,furnished with aspear; which we have stated, require an equal and generals, on their departure, and con- number of mechanical corrections of suis, pretorsand dictators, when they retired which the theory, simply considered, from office, sacrificed victims before them. takes no notice. In horology, therefore,

Pencil; an instrument used by paint- the pendulum must be considered not ers for laying on their colors. Pencils are simply as a self-moving pendulous body, of various kinds, and made of various without any tendency to come to a state materials; the larger sorts are made of of rest, but as a body whose motion is boar's bristles, the thick ends of which are perpetuated by repeated accessions of bound to a stick, large or sipall, according force in aid of its own gravity, and whose to the uses they are designed for; these, vibrations are repdered isochronal by a when large, are called brushes. The nice adaptation of mechanical contrivfiner sorts of pencils are made of camels, ances, that prevent or remedy the influbadgers' and squirrels' hair, and of the ence of all natural impediments to unidown of swans; these are tied at the up- form and uninterrupted motion. The first per end with a piece of strong thread, and kind of pendulum (the theoretical) is called enclosed in the barrel of a quill. Good a mathematical or simple pendulum, the pencils, when drawn between the lips, other the physical or compound pendulum. come to a fine point.

In the mathematical pendulum, the matter Lead Pencils. (See Plumbago.) of the pendulous ball or bob is supposed

Pencil of Rays; a number of rays di to be collected into one point, so that the verging from some luminous point, which, centres of gravity and of oscillation coinafter passing through a lens, converge cide. The doctrine of the pendulum is again to a point.

of the highest importance, but, as it canPENDANT. Two paintings or prints of not be fully developed without the aid of equal dimensions, which are attached in mathematics, nor rendered clear without corresponding positions to the same wall, diagrams, we can state only some of the are called pendants to each other.

most obvious properties and circumPendant, or PENNANT; a sort of long stances connected with it. A pendulum, narrow banner displayed from the mast once put in motion, would never cease to

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oscillate in arcs, were it not for the fric- basis for a calculation of the length of the
tion at the point of suspension, and the degrees in the various latitudes; but actu-
resistance of the air. Neither of these al measurements have shown that the
circumstances can ever be avoided en- meridians contain some irregularities, from
tirely, but their effect may be rendered which it bas been justly concluded, that
comparatively slight by giving to the the earth has not a perfectly regular form,
weight a lenticular shape, and suspending but deviates more or less from the shape
the rod on a sharp edge, on which it of a sphere. We can, therefore, properly
plays with very little friction. The times draw conclusions from the oscillations of
of the vibrations of a pendulum depend, the pendulum respecting the power of
J. on the magnitude of the angle of elon- gravity only, and not respecting the form
gation, viz. that angle by which the heavy of the earth. Besides the friction of the
body of the pendulum is removed from rod, &c., and the resistance of the air,
the vertical line; 2. upon the length of there are also other circumstances which
the pendulum; and 3. upon the accele- influence the oscillations of the pendulum.
rating power of gravity. If all these cir- These are the changes of heat and cold.
cumstances are perfectly equal in the case Heat lengthens the rod of the pendulum,
of two pendulums, they will perform an cold contracts it; hence common pendulum
equal number of oscillations in the same clocks go much quicker in winter; and the
time; but if there is a difference in either change of temperature in rooms which are
of the circumstances, the oscillations will heated during the day influences them con- ,
differ immediately. Thus, if one pendu- siderably. Many contrivances have been
Jum is shorter than the other, and all the devised for overcoming this inconvenience.
other circumstances equal, the shorter One is, by making pendulums of the form
pendulum will move quicker than the of a gridiron, consisting of several parallel

. The law which has been found bars of different metals, so connected that to exist is

, that the lengths of the pendu- the effect of one set of them counteracts lums are in an inverse proportion to the that of the others. These have been squares of their oscillations; hence the very successful. Rods are sometimes times of the oscillations are inversely as made of certain kinds of wood, well seathe square roots of the lengths of the pen- soned, which are little influenced by the dulums. Hence a pendulum which is weather. Astronomical clocks of the four times as long as another, will vibrate present day do not err to the amount of with but half the rapidity, or the shorter one beat or oscillation of the pendulum in pendulum will perform two oscillations a year. A common clock is merely a whilst the larger performs but one. The pendulum with wheel-work attached to it, pendulum does not perform its oscillations to record the number of vibrations, and in equal times in all parts of the earth. with a weight or spring to counteract the This is owing to the third of the circum- retarding effects of friction and the resiststances enumerated above, upon which ance of the air. Huygens, who developed the oscillations depend. The gravity, or, the doctrine of the pendulum, which had what is the same thing, the power of at- been treated already by Galileo, first aptraction in the earth, does not operate ev- plied it to clocks, and thus became the ery where with equal force on the pendu- inventor of the pendulum clock in 1656). Jum, which, therefore, in some parts of the (See Clock.–For the application of penearth, oscillates more slowly than in others. dulums to horology, see Berthoud's The cause of this lies in the centrifugal Essai sur l'Horlogerie (Paris, 1763, 2 force (9.v.), or in the diminution of the vols., 4to.).—See, also, Biot's treatise Sur la power of gravity caused by it. This be- Longueur du Pendule à Secondes, in the comes more perceptible the nearer the third volume of his Traité d'Astronomie place where the pendulum is observed Physique (second edition, Paris, 1810).is to the equator. (See Earth.) At See, also, Bode's Anleitung zur Kenntniss the equator, therefore, a pendulum vi- der Erdkugel (second edition, Berlin, 1803). brating seconds must be somewhat shorter PENELOPE. (See Ulysses.) than at a distauce from it. The length PENGUIN. (See Pinguin.) of a seconds pendulum at the equator is,

PENITENTIARIES. (See Prisons.). according to Biot, 39.011684 inches; in Pens, William, was born in London, in latitude 45°, 39.116820, in 90°, 39.221956. 1644. He was the only son of William If the globe were a perfect spheroid, Penn, of the county of Wilts, vice-admiral the meridians would be perfect ellipses, of England in the time of Cromwell, and and in such case the length of seconds afterwards knighted by king Charles II, pendulums would immediately afford a for his successful services against the

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