Page:Cyclopaedia, Chambers - Volume 2.djvu/542

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PYR

that the Solids do not vibrate fufficiently to keep the Fluids and the Appulfe of the Chvle See Digestion Twin-t- in their due Velocity, fication, &c. ' ' ' In thefe Cafes the Pulfe is low, and the Flefh cooler than At the bottom of the Pylorus is a laroe Cavity which

^Tt ft aTer m ufed for Powder of ca.cined Tin. See RS ^^^^trnt^^Z

T PUTURA,, jfttai claim'd by the Keepers of Forefls, ^ t", ^£t&1$X&j&$&

and fometimes Bailiffs of Hundreds, to take Man's Meat, of the Stomach, fuch. a Provifion /hould feem unneceflVv

Horle's Meat, and Dog's Meat, of the Tenants and Inha- See Lacteal.

bitants gratis y within the Perambulation of the Foreft, Hundred, £ffc. See Purlieu, Perambulation, &c.

This Cuftom within the Liberty of Knaresburg was long fince turned into the Payment of four Pence pro Putura.

The Land fubjeft to this Service, is calPd Terra Putu- rata. The learned Sommr erred in his Exposition of this

Word Johannes clamat unam Puturam in prior tttu de

<penevoftham,_ qui eft qiitsdam Cella Abbatice de Boejhmi pro fe & Miniftris, Equis £f; Garcionibus fuis per mmm diem & duas nocfes de trims Sefiimanis in tres Septimanas,

The Word is derived from the Greek wk»& ( Janitor, Door-keeper.

PYRAMID, in Geometry, a Solid flanding on a fquare Bails, and terminating a-top, in a Point : Ora Body whofe Bafe is a Polygon, and whofe Sides are plain Triangles ; their feveral Tops meeting together in one Point. See Solid.

Euclid defines it a folid Figure, confiding of feveral Triangles.'whofe Bafes are all in the fame Plane, and have

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, one common Vertex. See Triangle and Vertex. viz. de vittualibus, ut in efculentis & pocidentis, ad Coftas ffldfm defines it a Solid bounded by as many Trian- frioratus frtdlffi indebite— — Placit. apud Prefton. 17 flies, A DC, D C B, and A D B, terminating in one Point,

D5 as the Bafe ABC, has Sides. (Tab. Geometry, fig. 78.;

The pyramid is faid to be triangular, £>ziadr a uvular > ' guinquangidar, $§c. as the Bafe is triangular, quadran- gular, $$c — ThePyramid may becalPd a fquare,triangular, ££c. Cone 5 or the Cone, a round Pyramid. See Cone.

PYANEPSIA, in Antiquity, a Feafl: celebrated by the Athenians in the Month Fyanepfion ; which, according to the generality of the Critics, was their fourth Month, and correfponded to our September. See Feast.

Plutarch refers the Inflitution of this Feaft to T'hefeus 5 who, at his Arrival from Crete, made a kind of Sacrifice to Apollo of all the Provisions remaining in his Veffel 5 putting with his fix Companions 3 which Cuftom was afterwards continued.
 * em all into a Kettle, boiling 'em together, and eating 'em

ThcScholiaftof Arifiopfoanes fays, it W3s to acquit him- felf of a Vow he made to Apollo in a Tempeft.

M. Saudelot writes Tuanepjia ; and takes it to be a Feafl: inftituted in memory of T'hefeush Return after killing the Minotaur. See Minotaur.

The Greeks vary as to the Origin and Signification of the the word Pyanep/ion, whence the Feaft is denominated. — Harpocratian calls it P<sanopfia ; he adds, that others call it Panopfia, becaufe then the Fruits all appear to the Eye. Hefychius writes Pyanepfia b and derives it from srv*jt©-, Bean, and esrfa, I gather : becaufe in this Feaft the Athenians gathcr'd their Beans, and made a kind of Broth of 'em.

PYCNOSTYLE, or Pychnostyle, in the antient Ar- chitecture, a Building where the Columns ftand very clofe to one another j one Diameter and a half of the Column being only allow'd for the Intercolumination. See In- tercolumin ation.

The Pycnofiyle is the fmalleft of all the Intercolumi- nationsmention'd by Vitruvius.

The Word is form'd from the Greek mvw®' t clofe, and bvh@- t Column.

Some make the Pycnofiyle the fame with the Syfiyle 5 others diftinguifh the latter, by its allowing half a Module more in the Corinthian Intercolumination. See Systyle.

The Pycnofiyle, Mr. Evelyn obferves, chiefly belong'd to the Compofite Order 3 and was ufed before the mod mag- nificent Buildings, as at prefent in the Ferijlyle of St. Pe- ter's at Rome, confining of near 300 Columns 5 and fuch as yet remain of the Antients among the late difcover'd Ruins at' Palmyra.

PYCNOTICS, Medicines of an aqueous Nature, and which have the Faculty of cooling and condenfing, or thickening the Humours.

Such are Purflain, the Nenuphar, or "Water-Lilly, Sola- num, &c.

The Word in its original Greek, 4?vmqtik'oi>, fignifies fomething that has the power of thickening.

PYGMY, or Pigmy, or Pigmveus, a&warf, or Perfon of exceedingly fmall Stature, not exceeding a Cubit in height. See Dwarf and Giant.

The Appellation is given among the Antients to a fabu- lousNation, faid to have inhabited jfhrace, who generated and brought forth Young at five Years of Age, and were Old at eight 5 famous for the bloody War they waged with the Ccanes.

The Word is form'd of the Greek vvyjtH, Cubit. See Cubit.

PILING the Ground,, for Foundations. See Foun- dation.

PYLORUS, in Anatomy, the lower Orifice of the Sto- mach, whereby it difcharges itfelf into the Jnteftines. See Stomach and Intestines.

The Pylorus is fituate on the right fide of the Stomach, and paffes by an oblique Afcent to the 1>uodenum 5 to pre- v ent the too precipitate Paffage of the Aliment out of the Stomach. See Duodenum.

For this end, it is likewife fuminVd with an extraordi- nary Series of Fibres, to conftringe it more than any other part : Thefe running round it, ferve as a kind of Sphinc- ter, which is open'd by the Contraction of the Stomach,

Properties of the Pyramid.

t. All pyramids and Cones flanding on thefameBafe,and having the fame Altitude, are demonstrated to be equal.

2. A triangular Pyramid is the third part of a Prifm, flanding on the fame Bafe, and of the (ame Altitude, See Prism.

3* Hence, fince every Multangular may be divided into Triangulars; every Pyramid is the third part of a Prifm, flanding on the fame Bafis, and of the fame Alti- tude.

4. If a Pyramid be cut by a Plane abc, parallel to its Bale A BC 5 the former Plane, or Bafe, will be fimilar to the latter.

5. All Pyramids, Prifms, Cylinders, &t. are in a Ratio compounded of their Bafes and Altitudes : The Bafes, therefore, being equal, they arc in proportion to their Al- titudes ; and the Altitudes being equal, in proportion to their Bafes.

6. Pyramids, Prifms, Cylinders, Cones, and other fimi- lar Bodies, are in a triplicate Ratio of their homologous Sides.

7. Equal Pyramids, &c. reciprocate their Bafes and Al- titudes ■■} i. e. the Altitude of the one is to that of the other, as the Bafe of the one to that of the other, &e,

A Sphere is equal to a Pyramid, whofe Bafe is equal to the Surface, and its Height to the Radius of the Sphere.

8. A Pyramid is one third of the perpendicular Altitude, multiply'd by the Bafe.

To meafure the Surface and Solidity of a 'Pyramid ■ ■» Find the Solidity of a Prifm that has the fame Bafe with

the given Pyramid: Sse Prism. And divide this by

three 3 the Quotient will be the Solidity of the Pyramid.

Suppofe, v.gr. the Solidity of the Prifm be found 67010528 5 the Solidity of the Pyramid will be thus found 22356770-

The Surface of a Pyramid is had, by finding the Areas both of the Bafe ABC, and of the lateral Triangles ACD, CBD, BDA. See Triangle. The Sum of thefe is ■the Area of the Pyramid*

The external Surface of a right Pyramid, flanding on.* regular Polygon Bafe, is equal to the Altitude of one of the Triangles which compofe it, multiply'd by the whole Cir- cumference of the Bafe of the Pyramid.

¥0 defcribe a Pyramid on a Plane. — -;. Draw the Bafe, v.gr. the Triangle ABC; (if the Pyramid requir'd be triangular) fo as that the Side A B, fuppofed to be turned behind, be not exprefs'd. 2. On A C and C B, conftruct the Triangles ADC, and CDB, meeting in any afliimed or determined Point, v.gr. D, and draw A D, C D, BD ; Then will A D B C, be a triangular Pyramid.

To confr-uH a Pyramid of Paft-board, Wc, Suppofe,

v.gr. a triangular Pyramid required. 1. With the Radius AB, defcribe an Arch B E ; (fig. 79.) and thereto apply three equal Chords, B C, CD, and D F. 2. On D C con- flrucT: an equilateral Triangle D F C 3 and draw the right Lines AD and AC. This Paft-board, &c. being cut off by the Contour of the Figure, what remains within, will turn up into a Pyramid.

Pyramid, in Architecture, is a folid mafiive Edifice 5 which from a fquare, triangular, or other Bafe, rifes dimi- riiftiing, to a Point, or Vertex.

Pyramids are fometimes ufed to preferve the Memory of fingular Events, and fometimes to tranfmit to Posterity

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