P Y R 



P Y R 



The ftone coffin, he apprehends, was a trough or rcfervoir 

 for water, whicli, by me.iiis of the well, they drew from the 

 Nile. The priells of Egypt dehghted in obfcurity, and 

 they probably came by tht- fubterrareous pallagcs of the 

 building to the dark chambers within ; where they per- 

 formed their lullrations, and other noclurnal rites. Many, 

 he adds, of the ancient temples in this country were caverns 

 in the rock, enlarged by art, and cut out into numberlefs 

 dreary apartments ; for no nation upon the earth was lo 

 addidied to gloom and melancholy as the Egyptians. From 

 the top of the pyramids they obferved the heavens, and 

 marked the conftellations ; and upon the fame eminence 

 it is probable that they offered up vows and oblations. See 

 on this article Greaves's Works, vol. i. p. i, &c. Shaw's 

 Travels, fol. p. 413, &c. Pococke's Dcfcript. of the Ealt, 

 vol. i. p. 41, &c. Perry's View of the Levant, p. 413, &c. 

 Bryant's Anal, of Ancient Myth. vol. iii. p. 523, &c. 

 Farmer's Worfhip of Human Spirits, &c. p. 379, &c. 

 Savary's Letters, vol. i. 



The tomb of Porfenna, kmg of Etruria, at Clufuim in 

 Italy, is an ancient monument of fquare ftone, eacii fide of 

 which is three hundred feet broad, and fifty feet high. 

 Within the fquare bafe there is an inextricable labyrintli ; 

 apon this fquare there ftand five pyramids, four in the 

 angles and one in the middle, feventy-iive feet broad at 

 the bottom, and a hundred and fifty feet high, and ter- 

 minating in a point ; at top they are covered with a brafs 

 circle, from which are fulpended bells, which are put in 

 motion by the wind, fo as that tlieir found may be heard 

 at a great diftance. Upon this circle there are four other 

 pyramids, each a hundred feet high, above which, upon 

 one plane, there are five other pyramids. Such is the ac- 

 count which Phny gives from Varro, lib. xxxvi. cap. 13. 



Pyramid, Scenography nf a. See SceNography. 



Pyramid, Oj>lic. See Optic Pyramid. 



PYRAMIDAL Fountain. See Fountain. 



Pyramidal Mirrors. See Mirror. 



Pyramidal Numbers are the fums of polygonal numbers, 

 collefted after the fame manner as the polygonal numbers 

 themfelves are extrafted from arithmetical progrefTion. See 

 Numbers. 



Thefe are particularly called^^y? pyramidals. The fums 

 of firft pyrsmidals are called fecond pyramidals. And the 

 fums of thofe third pyramidals ; and fo on, ad infinitum. 

 Particularly, thofe arifing from triangular numbers are called 

 prime triangular pyramidals ; thofe arifing from pentagonal 

 numbers are called prime pentagonal pyramidal?, &c. The 

 numbers I, 4, 10, 20, 35, &c. formed by the addition of 

 the triangular numbers I, 3, 6, 10, &c. are .ufually called 

 by the fimple name of pyramidals ; and the general formula 



for finding them is « x x ; i. e. the fourth 



pyramidal may be found by fubflituting 4 for « ; the fifth, 

 by fubftituting 5 for «, &c. 



PYRAMIDALIA Corpora, in Anatomy, two pro- 

 minences in the medulla oblongata. See BEain, and Ner- 

 vous Syjlem. 



PYRAMIDALIS Abdominis, one of the abdominal 

 mufcles. See Obliquu.s. 



Pyramidalis Na/i, a name given by fome anatomifts to 

 that portion of mufcular fibres whicli defcends from the 

 fronto-occipitalis along the fide of tlie nofe. See Epi- 



CRANIUS. 



PYRAMIDOID, called alfo parabolic fpindle, a fohd 

 figure, formed by the revohition of a femiparabola r 

 flue of its ordinate;-. 



femiparabola round 



According to the method of indivifibles, this may be con- 

 ceived to confift of an infinite fcried of circles, wliofe 

 diameters are all parallel to the axis of the revolving 

 parabola. 



The parabolic fpindle is equal to T'jths of its circun 

 fcribing cylinder. See Spindle. 



Pyramidoid, Parabolic. See Parabolic Pyramidoid. 



PYRAMIDS, in Geography, rocks in the Eaft Indian 

 fea, near the E. coait of the ifland of Myfol. S. lat. i' 

 55'. E. long. 130^ 59'. 



PYRAMUS, GlHON, in Ancient Geography, a rjvei of 

 Afia, rifing in the country of Cataonia, where it begins to 

 be navigable, and traverfing mount Taurus through the 

 rocks, it enters the plain of Cilicia, paffes by the foot of the 

 mountain of Anazarbus, and leaving it to the right, throv,;, 

 itfclfinto Mopfuete, and at length lofes itfclf in the Mediter- 

 ranean, at the point where was formerly fituated the town 

 of Megarfus. 



PYRBAUM, in Geography, a town of Bavaria, and 

 capital of a lordfliip united to Salzburg; 13 miles SJi. 

 of Nuremberg. 



PYREN^UM PuoMONTORiUM, Cape de Creus, in 

 /Indent Geography, a promontory of Hifpai-iia Citeriur ; 

 which terminates the Pyrenees eaftwards, and projects inti. 

 tin- fea. 



PYREN^US Saltus, a name given by Cornelius 

 Nepos and Livy to that part of the Pyrenxan mountains- 

 winch Hannibal traverfed in his way to Italy, pafling from 

 Spain to Gaul. 



PYRENE, a town of Gallia Celtica, near the place 

 where the Danube rife?, according to Herodotus. 



Pyrene, in Natural Hi/lory, the name of a ftone found 

 always in the fhape of the ftone of an olive. It is of the 

 lapis Judaicus kind, being no other than the petrified fpinc 

 of fome fpecies of echinites. 



PYRENE'ES, in Geography, a chain of mountains, 

 celebrated fincc the time of Herodotus, forming the bound- 

 aries between France and Spain, and extending from the 

 Mediterranean to the Atlantic, about 200 miles in length, 

 and in its greateil breadth 100 miles. Its various branches 

 are diftinguidied by different names, and may be confidered 

 as belonging either to France or Spain. The higheit fummits 

 of thefe mountains, which are in the centre of the chain, 

 have prefented to the refearck of the naturalift not only cal- 

 careous appearances, but even fhells. The higheft elevation 

 of the Pyrenees is Mont Perdu, for an account of which, 

 we refer to that article. The Canigou was formerly 

 reckoned the highell fummit, though it does not exceed 

 8544 Englifli feet. Other noted heights are Tuccarroy, 

 Marbore, the pic de Midi, 9300 feet high, the pic de 

 los Reyes, 7620 feet high, the pic d'Offano 11,700 feet 

 in height, the pic d'Arni, the Niege Veille, the Vigne 

 Mali, La Breche de Roland, &c. At a diftance the 

 Pyrenssan chain appears like a fhaggy ridge, prefenting 

 the fegment of a circle fronting France, and defcending at 

 each extremity till it difappears in the ocean and Mediter- 

 ranean. Thus, at St. Jean de Luz, only high hills appear, 

 and in like manner on the eaft beyond the fummit Canigou, 

 the elevations gradually diminifh. The higheft fummits are 

 covered with perpetual fnow. Blocks of granite are inter- 

 fperfed with vertical bands, argillaceous and calcareous, the 

 latter primitive or fecondary, and fupplying the marbles of 

 Campan and Antin, of beautiful red fpotted with white, 

 though the general mountain mafs be grey. To the S. and 

 W. the Pyrenees prefent nothing but dreadful fterihty, but 

 on the N. and E. the defcent is more gradual, and affords 

 frequent woods and paftures. Befidcs the dreadful fall of 



3 rocks. 



