Page:Cyclopaedia, Chambers - Volume 2.djvu/533

 PUM

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PUN

The Forcing-Tump, which afts by mere impulfe or pro- trufion, and ruifes Water to any Height at pleafure : — And Ctefebes's Pump, the firft and fineft of 'em all, which afts both by Suction and Expulfion. — The Structure of each is as follows.

StruSure and ASion of the Common or Sucking Pome.

1. A hollow Cylinder or Barrel A BCD, (Tab. Hy- drostatics, fig. 27.J is provided, of any folid Matter, ufually Wood 5 and erected perpendicularly in a Spring, or other Source of Water : The lower Bafe of the Cylinder being firft fitted with a Valve I, which opens upwards.

2. A Pifton or Embolus, call'd the Sucker, EK, fur- nifh'd with a Valve L.which likewife opens upwards, is let down the Cylinder ; and for the more eafy working upwards and downwards, furnilh'd with a Lever, as G H. See Em- bolus and Valve.

Now, the Embolus E L, being drawn up from I to L, will leave the Space L 1 void of Air, at leaft in a great meafure fo : The preffure, therefore, of the Air on the Surface of the ftagnant Water prevailing, will, by the Laws of Hydroflatics, lift up the Valve I, andraifeit to fill the Cavity L I. Sec Air and Siphon.

If, then, the Embolus be again let down ; the lower Valve being nowfaft clofed with the Weight of the incum- bent Water, upon preffing the Pifton, the Water muft open the upper Valve, and get into the Embolus, by which it is raifed up and difcharged out at the Spout H.

Thus is the Embolus alternately raifed and depreffed, £tfc. See the theory of the Pump more accurately laid dozen under the Article Syringe.

StruSure and ASionof a Forcing Pomp.

1. In a Cylinder A B, (Fig. 28.) is divided by a Dia- phragm, or tranfverfe piece, CD, fitted with a Valve E, opening upwards; and thus immergedin Water.

2. An Embolus F, furnilh'd with a Valve G, is fo fitted to an Iron Rod I H, moveable on a Hinge at H, as that it may be conveniently raifed and depreffed by the Hand ap- ply'd in K.

Now, upon depreffing the Embolus F, the Water will open the Valve G, and thus afcend into the Cavity of the Cylinder B C : But upon railing it again, the Valve G is fbut ; fo that there is no Paffage for it that way : The Valve E, therefore, becomes open'd, and the Water mounts hro'it; and by repeating the Agitation of the Embolus, fs at length driven out through the Spout M. ' The great difficulty of rectifying this 'Pump when it happens to be out of Order, on account of the chief Seat of Action's being under Water, makes People decline the Ufe of it, when they can do well without it j notwithstanding its Advantage of railing the Water toany given Height.

StruSure and ASion o/Ctefebes Pump.

1. A brafs Cylinder A BC D, {Fig. 29.) fumifli'd with a Valve in L, is placed in the Water. 2. In this is fitted the Embolus M K, made of green Wood which will not fwell in the Water, and adjufted to the Aperture of the Cy- linder with acovering of Leather 5 but without any Valve. In H is fitted on another Tube N H, with a Valve that opens upwards in I.

Now, the Embolus E K being raifed, the Water opens the Valve in L, and rifes into the Cavity of the Cylinder. — And when the fame Embolus is again deprefs'd, the Valve 1 isopen'd, and the Water driven up thro the Tube H N.

This is the Pump ufed among the Antients ; and that from which both the others are deduced. — Sir S. Morland has endeavour'd to increafe its Force, by leflening the Friction ; which he has done to good effea : Infomuch as to make it work without, almoft, any Friction at all.

Pumps, ufed in Ships, are of feveral Kinds : As, the Cham-Tump, ufed in large Veffels. This yielding a great Quantity of Water, works eafily, and iseafily mended.

Bare-Tumps are fmall ones made of Cane, ora piece of Wood bored thro', ufed in lieu of Cocks, i$c. to pump Beer or Water out of the Casks.

Bur-Tumps, call'd alfo Bildge-Titmps, are chiefly ufed by the 2>utch, who have 'em by their Ships-fides. In thefe is a long Staff with a Bur at the End like a Gunner's Spunge, toptimp up the Bildge-Water. See BvB.-Tump.

Air-Vvuv, in Pneumatics, is aMachine by means whereof the Air is emptied out of Veffels, and a fort of Vacuum produced therein. See Air and Vacuum.

For the Invention, StruSure, and Ufe of this Tump ; fee Aw.-Tump.

PUN, or Punn, a Lufus Verborum, or Point, the Wit whereof depends on a refemblance between the Sounds or Syllables of two Words, which have different, and, per- haps, contrary Significations. See Point and Wit.

Such are Cane ^Decane Cane— Far Mole, Mole, Molt.

Lex 2)ei, LuxlJiei All-houfes are Ale-houfes.

The holy State of Matrimony, is become Matter of Money.

Some Men's Paradife is a pair of Dice. Was it fo in

the time of Noah i Ah no.^—Z'Ordre tire du -Uifordre, ou SJifcrdre Ordotme, is the Title of a French Book.

Tuns, when they come eafily, and are very ingenious, poignant, and appofite, are atlow'd of in Converfation, Letters, Epigrams, Madrigals, and the like Compositions 5 but are ablolutcly banijh'd out of the grave, feriuus, and fublime, by reafon they weaken its Force and diminiih its Beauty which confifts in fomething great and elevated. The Greeks and Romans, 'tis true, tometimes indulged themlelves the Practice, and ufed them as Ornaments in the moft ferious Difcourfes. But the more fevere and phi- lofophical Genius of our Age, is by no means futisfy'd with fuch an outride of Wit. — Devifes, Symbols, Rebus's, Motto's, cifc- are their proper Sphere, where they fhine to moft avantage. See Devise, Rebus, £$c.

PUNCH, an lnftrument of Iron or Steel, ufed in fe- veral Arts, for the piercing or ftamping Holes in Plates of Metals, £S?c. being fo contrived, as not only to perforate, but to cut out and take away the Piece ; whence the French call it Emporte-piece, q.d. take-off piece.

The Punch is a principal lnftrument of the Metal-Button- Makcrs, Wafer-Makers, Patch-Makers, Shue-Makers, SSc.

The Tunch ot the Makers of Plate Buttons ferves to cut and parcel out the Plates of Gold and Silver wherewith they cover their Moulds. — 'Tis large, round, four, or five Inches high, the bottom hollow for about half an Inch, well fteel'd, and the Edge very (harp.

To ufe it, they extend the Plate of Metal on a leaden Table or Block, and with a pretty heavy Hammer; firike the Head of the Punch, i^c. See Button -Making.

In the Manage, a Punch Horfe, is a well let, well-knit Horfej fhort-back'd, and thick-fhoulder'd, with a broad Neck, and well lined with Flefti.

Punch, is alfo a foft of compound Drink, frequent in England, and particularly about the Maritime Pans thereof j tho' little known elfewhere- See Drink.

Its Bafis is Spring- Water, which being render'd cooler, brisker, and more acid with Lemon-Juice, and fweeten'd again to the Palate with fine Sugar, makes what they call Sherbet 5 to which a proper Quantity of a fpirituous Li- quor, as Brandy, Rum, or Arrac being fuper-added ; the Liquor commences Tunch.

Several Authors condemn the Ufe of Tunch as prejudi- cial to the Brain, and nervous Syftem. — Dr. Cheyne infills that there is but one wholefome Ingredient in it, which fome now begin to leave out, viz. the mere Element. See Water, Brandy, Rum, Arrac, Sugar, i$c.

The proportions of the Ingredients are various 5 ufually the Brandy and Water are in equal Quantities.

Some, inftead of Lc on- Juice, ufe Lime-juice, which makes what they call ^unch Royal ; found lefs liable to affcel the Head, as well as more grateful to the Stomach.

Some alfo make Milk-Punch, by adding near as much Milk to the Sherbet as there is Water ; which Tempers the

Acrimony of the Lemon. Others prefer lea-Tunch,

made of green Tea inftead of Water, and drank hot.

Laftly,What they call Punch for Chamber- Maids is made without any Water ; of Lime-juice, fharpen'd with a little Orange and Lemon-Juice ; twice as much white Wine as Lime-juice, and four times as much Brandy, with Sugar.

PUNCHIN, orPuNCHioN, in Building. See Pun-

CHION.

PUNCHION, a little Block, or Piece of Steel, on one End whereof is fome Figure, Letter, or Mark engraven either in Creux, or in Relievo; Impreffions whereof are taken on Metal, or fome other Matter, by ftriking it with a Hammer, on the End not engraved. See Engraving tic.

There are various Kinds of thefe Tunchions ufed in the Mechanical Arts— —Such, for inftance, are thofe of the Goldfmiths, Cutlers, Pewterers, e?c. See Mark.

Punchion, in Coining, is a piece of Iron fteel'd, where- on the Engraver has cut, in Relievo, the feveral Figures, Arms, Effigy, Infcription, igc. that are to be in the Ma- trices, wherewith the Species are to be mark'd. See Ma- trix, &c.

Coiners diftinguifh three Kinds of Tunchions, according to the three Kinds of Matrices to be made : that of the Effioy, that of the Crofs or Arms, and that of the Legend or In- fcription.

The firft includes the whole Portrait, in Relievo. — The fecond are fmall, each only containing a piece of the Crofs or Arms, v.gr. a Flower-de-Lys, a Harp, a Coronet, Zye. by the Affemblage of all which, the entire Matrix is form'd. — The Tunchions of the Legend only contain each a Letter, and ferve equally for the Legend on the Effigy- fide, and the Crofs-fide, See Coining.

For