Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/227

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ferent fliapes, according to their various fpecies j in fome they , are round, and in others angular, and in fome the columns are perfectly feparatej in others, the ftrite of the feveral co- lumns run one into another. The ftones which contain the hollowed liars, are often befet with numerous tubercles, and the ftars are often elegantly hollowed, and not unufually they are full of cavities, round at their external furface, and only ftarr'd at the bottom : The cavities of thefe alfo often run very deeply and irregularly into the fubftance of the flone.

ASTROLUS, in natural hiflory, a name given by authors to a white and fplendid ftone, final I in fize, and of a roundifh fi- gure, refembling the eyes of fifties.

ASTROMETEOROLOGIA, the art of foretelling the wea- ther, and its changes, from the afpects and configurations of the moon and planets. Wolf. Lex. Math. p. 198. This makes a fpecies of aflrology, diftinguifhed by fome under the denomination of Meteorological Aflrology. Dr. Goad publifhed a large work in folio, exprefs on this fubjeft, 1686, which he afterwards tranflatcd from Englifh into Latin, and publifhed it at London in 1690. 4 . con- taming a fort of fyftem of prognostications of the weather. To the fame head alfo belong Coke's Meteor ologia, firft pub- lifhed in Englifh, and fince in High Dutch at Hamburgh, 1691, 8°.

AS rOMI, Arofioi, in anthropology, people feigned without mouths. Pliny (peaks of a nation of Aflomi in India, who lived only by the fmell or effluvia of bodies, taken in by the nofe. Brown, Vulg. Err. 1. 3. c. 21. p. 131. Men without mouths are certainly fables ; or, at heft, mon- fters ; for we have inftances of children born, not only with- out mouths, but heads.

The pond mufcle is obferved by naturalifts, to be a fort of ajlomofe animal. It takes in it food by the anus, that is, at the fame aperture whereby it evacuates it again.

ASTROPECTEN, in natural hiftory, a name given by fome authors, to a fpecies of ftar-fifh, compofed of a body, or cen- tral nucleus, furrowed in the manner of the fhells of the com- mon fcallop, and parting into five principal rays, from each of which there illiie feveral tranfverfe procefles, covered with a hairy down.

AS EROSCOPE, Afirofcopium, a kind of aftronomical inftru- ment, compofed of two cones, on whofc furface the conftel- lations, with their ftars, are delineated, by means whereof the ftars may eafily be known. Wolf. Lex. Math. p. 207. , The Ajlrofcope is the invention of Wil. Schukhard, formerly profeflbr of mathematics at Tubingen, who publifhed a trea- tife exprefly on it, in 1698.

AS'I ROSCOPIA, the art of obferving, and examining the liars, by means of telefcopes, in order to difcover their nature and properties. Wolf Lex. Math. p. 206. Huygens improved this art confiderably, in his AJlrofcopi 'a com- pendiaria tubi optid molimine liberata \ where he thews how to manage the largeft glaftes without help of a tube. Wolf. Elem. Dioptr. §. 372. See Telescope.

ASTROTHEMATA, in aftrology, the places or pofitions of the ftars, in a theme of the heavens. Vital. Lex. Math.

P- 73:

ASTROTHESIA is ufed by fome for a conftellation, or image in the heavens, compofed of feveral ftars. Vital, loc. cit.

ASTRUM, or Astron, a conftellation, or affemblage of ftars. In which fenfe it is diftinguifhed from After, which denotes a fingle ftar.

Some apply the term in a more particular fenfe, to the great dog, or rather to the great bright ftar in his mouth. Vital. Lex. Math. p. 72. In this fenfe we meet with In Afro, extra Aftrum, &c.

ASTURIS, in zoology, a name by which fome authors have called the Accipiter Palumbarius, or Gofhawk. Ray's Orni- thol. p. 51. Seethe article Palumbarius Accipiter.

ASTYNOMUS, Art™,*©., (Cyd.) in antiquity, an officer at Athens, appointed to take care of the ftreets, infpe£t the buildings, waters, &IV. Pott, Archasol. 1. 1, c. 15. Pitifc Lex. Ant. p. 194.

The Aflynomi at Athens were much the fame with the ^diles at Rome. Ariftotle, as cited by Harpocratian, makes ten Aflynomi, five in the city, and as many in the Piraeus. Sam, Petit, imagining a corruption in the numbers of Harpocratian 5 : text, inlarges their number to fifteen, of which he diftribut.es ten to the city, and five to the Piraeus. The Aflynomi were officers of weight and authority, and are frequently called, in the antient laws, curators, or fathers of the ftate ; fometimes fimply fathers, patres. Papinian wrote a treatife exprefs concerning the A/rynomi. Pitifc. loc. cit.

ASYMPTOTE {Cycl)—Afymptotes are diftinguifhed into va- rious orders.

An Afymptote h faid to be of the firfi order, when it coincides with the bafc of the curvilinear figure : Of the fecond order, when it is a right line, parallel to the bafe ; of the third order, when it is a right line oblique to the bafe ; of the fourth order, when it is a common parabola, that has its axis perpendicular to the bafe j and, in general, of the order r-f-2, when it is a parabola, the ordinate of which is always as a power of the

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bafe, whofc exponent is r. See Maclaurin\ Fluxions, Art. 334, feq.

The Afymptote is oblique to the bafc, when the ratio of the firft fluxion of the ordinate to the fluxion of the bafc, ap- proaches to an aflignable ratio, as its limit ; but it is parallel to the bafe, or coincides with it, when this limit is not affien- able. 6

The determination of the Afymptotes of curves, is a curious part of the higher geometry. Mr. de Fontenelle has given feveral theorems relating to this fubjecl:, in his Geometric de Vlnfim. But this matter is treated of with greater accuracy by Mr. Mac laurin, in his fluxions, book I. chap. 10. where he has been careful to avoid the modern paradoxes, not to fay jargon, concerning infinites and infiniteumals. The areas bounded by curves, and their Afy?nptotes, though indefinitely extended, fometimes have limits to which they may approach, fo as to differ lefs from thofe limits, than by any given quantity. This happens in hyperbolas of all kinds, except the firft, or Apollonian. The fame is alfo true of the area, comprifed between the logarithmic curve and its Afymptote. V. Maclaurin, B. 1. c. 10. See Loga- rithmic Carve.

Thofe who do not fcruple to fuppofe the curve and its ^/ym^/a/t', to be infinitely produced, fay, that the infinitely extended area becomes equal to its limit.

The afymptotical area in the common or Apollonian hyper- bola, and in many other curves, has no limit ; and' it is ufual to fay, thefe areas are infinitely great ; by which, how- ever, no more is meant, than that the curve, and its Afymp- tote, may be extended, till the fpace comprehended between them, exceeds any given magnitude.

Some authors, and Dr. Wallis among the reft, have talked of fome of thefe areas, as if they were more than infinite. This happened from an analogy they imagined between pofi- tive, nothing, and negative, and what is finite, infinite, and and more than infinite. Lib. cit. Art. 294. See the article Hyperbola.

Solids generated by hyperbolic areas, revolving about their Afymptotes, have fometimes alfo their limits ; and fometimes they may be produced, till they exceed any given folid. See Art. 307, 309, of the before-mentioned author. When a curve, and its Afymptote, are fuppofed to be pro- duced infinitely, and the area, comprifed between them, to revolve about the Afymptote, the furface generated will be fi- nite, or infinite, according as the area of the generating figure is finite or infinite. Cotes, Harm. Menf. p. 94. Schol. Maclaur. Flux. Art. 339. p. 283.

For the Afymptotes of curves, defcribed by the interfections of of right lines revolving about given poles, fee Mr. Maclau- rin's Fluxions, Art. 313. feq.

Parabolic Asymptote. See Parabolic Ajymptote.

ATABULUS, in phyfiology, a provincial wind in Apulia, of a dry pinching quality, and very noxious in its effects. V. Plin. Hift. Nat. 1. 17. c. 24. Senec. Queft. Nat. 1. 5. c. 17. Vital. Lex. Math. p. 73.

The antient naturalifts fpeak of the Atabulus in terms of hor- ror, on account of the ravage it made among the fruits of the earth, which it fcorched, or withered up.

ATANTA, in botany, a name given by the people of Guinea to a kind of fumach, called, by Petiver, Rhus Guineevfe tri- foliatum ferratum fcabium, from its being trifoliate, and hav- ing rough and ferrated leaves. This fomewhat refembles the hoary trifoliate African fumach ofPlukenet, but it differs in this, that its leaves are edged with prickles, whereas thofe of Plukenet's kind are only deeply finuated. The people of Guinea are very fond of this, for its medicinal virtues ; they give it as a reftorative, boiled in water. Phil. Tranf, N°. 232.

ATCHE, in commerce, a fmall filver coin, current in the ftates of the Grand Seignor, equal to about a third part of the Englifh penny.

The Atcbe is the fmalleft coin ufed in Turkey ; where there is no copper money current, except in the province of Baby- Jon.

Some call the Atcbe the little Afper ; It is ftamped like the Para, with Arabic characters. Three or four Atches are commonly given in exchange for the Para. Savar. Diet, Comm. Suppl. p. 35. feq.

ATEGAR, a weapon among the Saxons, which feems to have been a hand dart. The word comes from the Saxon Aeton 9 to fling, or throw, and Gar, a weapon. Spelma?: and Blount, in voc.

ATELEIA, AteXuk, or Ate^ehj, denotes an exemption from tribute, taxes, or other burthens. Calv. Lex. Jur. p. 96. a. AnHiw >.nTH(yyi(i.aCim, is particularly ufed, in fome antient laws, for an exemption from offices, granted the Egyptian clergy by Conftantius. Bing. Orig. Ecclef. 3. 5. c. 3. §. 12.

ATH, Atha, orATHE, among our Anglo-Saxon Anceftors, fignifies an oath, efpecially that taken by way of Purgation. Du Cange, GlofT. Lat. T. 1. p. 369. In this fenfe we meet with breaking of Ath, privilege of Ath, Atha, and Ordela.

ATHENA, Ahvu, in the antient phyfic, a plaifter, or liniment, commended againft wounds of the head and nerves, of which