PUN
PUP
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is rivetled firmly, and the part where it is to be fixed on the frame,or shell, of the piston, is grooved for the purpose of giving it pli-ancy, that it may work up and down as if on a hinge. Fig. 14shews the plan; and fig. 15 the profile of this valve, which ischeap, simple, and easily repaired, though it has the defect ofbeing liable to choke, and of not rising high enough to allow a suf-ficient passage for the water. Fig. 16 shews a button-valve, whichis merely a piece of turned metal, A, having a shank, B, of abouteight inches or a foot in length, according to the depth of theblock, .r t. The shank passes through the bar, C, at the bottomof the block, and is prevented from coming up too high by thestud, or nut, o, at its bottom. When the water rises, it forces upthe button, A, and passes through the hollow in the block, ofwhich the superior part is expanded so as to lit the button, whichBeing the frustrnm of a cone, necessarily fits close into the ex-panded part as the water presses it, after having passed upwards inconsequence of the descent of the piston ; which may either besolid, as in a forcing pump, or valved, as in a lifting or a suckingpump. This valve may be applied to a piston, as well as to thatpart of the pipe which retains the water, that it may be withinreach of the piston’s action. An improvement has been made tothis valve, by adding a hall of some weight to the bottom of theshank, B, and excavating the button, in order to reduce its weightin proportion: this insures the regular descent of the button to itsscat. The butterfly-valve, exhibited in fig. 17, varies from thetwo former, in having two semicircular flaps appended by hingesto a bar passing over the centre of the excavated piston. Thisvalve is peculiarly eligible, because if one part should he stiff, andadhere to the piston, the other will play with an increased effect,though not equal to the action of both valves. The simplest valvewith which we are acquainted is the sphere, which is made of me-tal, and fits into a seini-spherical cavity on the top of the piston orblock. When the piston (if it be on that) rises, the sphere fallsinto the socket; but when the piston is depressed, the rush of wa-ter from below forces the sphere upwards. The only inconve-nience attendant upon this valve, which is shewn at fig. 18, is,that its diameter being nearly equal to that of the bore, leaves avery narrow passage for the water. This, however, might perhapsbe obviated, by making an excavation in the pipe, as shewn bythe doited lines, and by driving nails through to obstruct the hailfrom rising too high. These are the valves in most general use;we might notice several others, but our limits will not permit usto enter more minutely into the subject.
PUN , an expression, in which the same word is applied to dif-ferent meanings.
PUNA, an island in the Pacific Ocean , near the W. coast ofAmerica , in the Bay of Guayaquil, about 35 miles long, 12 broad,and 60 in circumference.
Pox a, the capital of the above island. Lon. 81.6. W. Lat. 3.17. S.
PUNCH, an instrument of iron or steel, used in several arts,for the piercing or stamping of holes in plates of metals, &c. beingso contrived as not only to perforate, but to cut out and take awaythe piece. It is a principal instrument of jewellers, the metal-button-makers, shoe-makers, &c.
Punch, a compound liquor, much used in Britain , hut morefrequently in Jamaica, and other parts of the West Indies . Thebasis of this beverage ought to be good spring-water; which, beingrendered cool, brisk, acidulated with lemon-juice, and sweetenedwith fine sugar, forms an agreeable and wholesome drink, calledsherbet: on adding a proper quantity of brandy, rum, or arrack,the composition is then denominated punch.
PUNCHEON , PUNCH IN, or PUNCHION, a little blockor piece of steel, on one end whereof is some figure, letter, ormark, engraven either in creux or relievo, impressions whereof aretaken on medal, or some other matter, by striking it with a hammeron the end not engraved.
Puncheon , in carpentry, is a piece of timber placed uprightbetween two posts, whose bearing is too great; serving, togetherwith them, to sustain some large weights. This term is also usedfor a piece of timber raised upright, under the ridge of a building,wherein the legs of a couple, &c. are jointed.
Puncheon , in coining, is a piece of iron steeled, whereon theengraver has cat in relievo the several figmes, arms, el'figv, in-scription, &c. that are to be in the matrices, wherewith the speciesare to be marked. See Coinage,
Puncheon is also a measure for liquids, containing an hogsheadand one-third, or eighty-four gallons. Ruin is brought from thecolonies in puncheons, which are large casks, containing about130 gallons.
Puncheon is also used for several iron-tool 1 -, of various sizesand figures, used by the engravers en creux on metals. Seal-gravers particularly use a great number for tire several pieces ofarms, &c. to be engraven, and many stamp the whole seal from asingle puncheon.
Puncheon is also a common name for all those iron-instrumentsused by stone-cutters, sculptors, blacksmiths, See. for the cutting,inciding, or piercing, their several matters.
Puncheons used in stamping the matrices wherein the types ofprinting characters are cast. See Foundeky.
PUNCTATED HYPERBOLA, an hyperbola whose ovalconjugate is infinitely small, i. c. a point.
PUNCTUATION, in grammar, the art of pointing, or of dtviding a discourse into periods, by points expressing the pauses tohe made therein. The points used are four, viz. the period, co-lon, semicolon, and comma. See the particular use of eachunder its proper article, Colon, Comma, Period, and Semi-colon.
PI NCTUM, [Lat.] a point; a period; a full stop. Theword is also used in other senses: as, .
PtNCTUM Saliens, in anatomy, the first rudiments of the heartin the formation of the foetus, where a throbbing motion is per-ceived.
Punctum Stans, a phrase hv which the schoolmen vainly at-tempted to bring within the reach of human comprehension thepositive eternity of Clod. See Metaphysics.
PUNCTURE, in surgery, any wound made by a sharp-pointedinstrument.
PUNDITS, or PANDITS, learned Brant ins devoted to thestudy of the Shanscrit language, and to the ancient sciences, laws,and religion, of Idindostan. See Bramins.
PUNGO ISLANDS, a cluster ol islands, near the coast of Be-nin, at the mouth of the Gabon : The principal one is six miles incircumference. They are governed by a king.
PUNIC, [from Paul, or Phoenicia ,J a name given by the Ro-mans to any thing belonging to their rivals the Carthaginians.
Punic Faith, [Punka fiiks, Lat.] a proverbial expressionamong the Romans, for unfaithfulness to promises, or breach oftreaties: a crime to which they alleged the Carthaginians wereaddicted: hut of which they themselves were evidently moreguilty, from the whole history of their last war with that unfortu-nate people.
PUNICA, the Pomegranate Tree; a genus of the monogy-nia order, and icosandria class of plants ; natural order, Pomacex.Calvx five-cleft, superior; petals five; pome many-celled, many-seerfed. There are two species.
PUNISH MEN']', in law, the penalty which a person incurs onthe breach or transgression of any law. The forms and marinersof punishment are various in different ages and countries, and forvarious crimes, as treason, felony, adultery, parricide, tkc.Among us the principal civil punishments are fines, imprisonments,the stocks, pillory, burning in the hand, whipping, ducking-stool,hanging, transportation, &c. The ecclesiastical punishments arecensures, suspensions, deprivations, degradations, excommunica-tions, anathemas, penances, &e. The military punishments are,being shot, running the gantclope, riding the wooden horse, &c.
PUNITORY INTEREST, in the civil law, such interest ofmoney as is due for the delay of payment, breach of promise, &c.
PIJNO, a town of South America , in Buenos Ayres, the capitalof Paucar Colla, on the W. bank of Lake 'Titicaca , ()(.) milesN. E. of Arequipa .
PUNTADEST. ANDREA, a cape on the coast of Friuli ,on tire Adriatic. Lon. 12. 18. E. Lat. 45. 45. N.
PUPA, in entomology, a term now used by zoologists for thatstate of insects, formerly called anrelia, and chrysalis. See Chry-salis, Entomology, and Nymph .
PUPIL , in anatomy, a little aperture in the middle of the uveaand the iris of the eye, through which the rays of light pass to thecry>talline humour, in order to he painted on the retina, and causevision. Sec Anatomy..
Pupil,