Page:Cyclopaedia, Chambers - Volume 2.djvu/299

 QBJ

(M)

OBJ

charg'd with Infcriptions and Hieroglyphics. See Monu- ment.

The difference between Obelisks and Pyramids, according to fome, confifts in this, that the latter have large Bafes, and the former very fmall ones.

ThoCardan makes the difference toconfifl in this, that Obe- lisk arc to be all of a piece, orconfift of a fingleStone, and Pyramids of feveral. See Pyramid.

The Proportions of the Heighth and Thicknefs are nearly the fame in all Obelisks i that is, their Height is nine, or nine and a half, fometimes ten times their Thicknefs; and their Thicknefs, or Diameter a-top is never lefs than half, nor greater than three fourths of that at bottom.

This kind of Monument appears very anfient; and we are told was firft made ufe of to tranfmit to Pofterity the principal Precepts of Philofophy, which were engraven in hieroglyphical Characters hereon.

In After-times they were ufed to immortalize the Actions of Heroes, and the Memory of Perfons beloved.

The 6rft Obelisk we know of, was that raifed by Ramifes, King of Egypt, in the time of the Trojan War. It was 40 Cubits high, and, according to Herodotus, employ'd 200GO Men in the Building. Pbius, another King of Egypt, raifed one of 45 Cubits; and Ptolemy Pbiladelphus another of 88 Cubits, in memory ctt~ Arfime.

Augujlus erected one at Rome in the Campus Martins, which ferv'd to mark the Hours on a horizontal Dial drawn on the Pavement. See Dial.

F.Kircber reckons up 14. Obelisks celebrated above the reft, viz. that of Alexandria, that of the Barberins, thofe of Gonftantinople, of the Mons Efnuilinus, of the Campus Flami- tiius, of Florence, of Heliopolis, of Ludoviflo, of S.Mabut, of the Medici, of the Vatican, of M. delists, and that of Pam- pbila.

The Egyptian Priefls call'd Obelisks the Sun's Fingers, be- caufe ferving as Styles, or Gnomons to mark the Hours on the Ground. The Arabs flill call them Fbaraob's Needles : whence the Italians -call them Aguglia 5 and the French, Aiguilles.

Borel derives the Word from the Greek Ifchlc, a Broach, Spindle, Point, or a kind of long Javelin.

Pliny fays, the Egyptians cut their Obelisks in form of Sun- Beams; and that in the Pbasnician Language, the word Obelisk fignifies Ray.

Obelisk, in Grammar, is a Character, in form of a Dagger (tj ferving to refer the Reader to fome Note, or other Matter in theMargin. See Character.

OBELUS, in Antiquity, is a little Line, or Stroke, like a Needle; whence its Name, ofchos, Needle.

The Word is chiefly ufed in fpeaking of Origeu't Hexapla; wterein he diflinguifhes, with an Afterisk, or Star, the Sup- plements he makes to the Text of the Septuagint, where it falls fhort of the Hebrew meaning; and with an Obelus, or little Line ( — j thofe Places where the Septuagint had any thing not in the Hebrew. See Hexapla.

St. 'jenm fays, the Oie/«i was only ufed in thofe Places where fomething was to be rctrench'd from the Seftuagint, as fuperfluouJ j and the Afterisk in thofe that were defective.

Thele Marks frequently occur in anticnt Manufcripts. TJfually the Obelus is accompanied with two Dots; the one above, the other underneath, as (--); and the Afterisk, a St. Andrew'&Croi~s, canton'd with four Points.

OBESITY, Fatnefs, in Medicine, the State of a Perfon too much charged with Fat, and Flefh; otherwife call'd Corpulency. See Fat.

Etmuller defines it to be fuch an increafe both of the Ven- ter and Limbs, as impedes the Aflions of the Body, efpe- cially Motion and Refpiration.

Obejity, Boerbaave obferves, does not confift in the Solids of the Body being increafed, but by their being diftended to a greater Pitch by the abundance of Humours collefted in them. SeeSoi.iD, l$c.

Hence, Obefity occafions feveral Difeafes; ufually Apo- plexies.

It was held Infamous among the Lacedemonians. Hiflory tells us of a Spaniard who had been fo exceedingly Fat, that when he became lean again, his Skin would make feveral turns or folds quite around him. Semscrtus mentions a Man that weigh'd 600 Pounds.

Emuller affirms, that there is no better Remedy againft Obefay than Acetum Scilliticum. Eorel recommends the Chew- ing of Tobacco; which Etmuller diffuades, left it induce a Confumption.

OBJECT, in Philofophy, fomething apprehended, or preff.tcd to the Mind, by Senfation, or by Imagination. See Sensation and Imagination.

Or, Object is fomething that affecls us by its Prefence - or fomething that moves the Eye, Ear, or fome of the other Organs of Senfe; or, at leaft, is reprefented to us by the

'"TLnt^saretheimmediateO^of the Mind in ,hi„ k . SS^V^di P* f*? *" £ «- fa*, Bodies, their Relations, Attributes,^, themediat fhe otjeB^M^jL " ^ humM B ° dy "

Formal

be that about which a Power, Aft, or Habit, is employ'd. Thus, Good is the ObjeB of the Will; Truth of the Under- Handing : So, Colour is the Ob Je a of Sight; Sound of Hearing, iSc. See Objective.

There are feveral Conditions requifite to an ObjeB of Senfe ■ as, that it be Material; that it be within a certain diftance of a competent extent, its fenfible Qualities fufficientlv in- terne, £$c. '

Tis the Oiy'eS that reflects or emits the Rays of Light which occafion Vifion. ObjeBs of themfelves are invifible; we only feem to perceive them becaufe the different Tex- ture of their Surface, difpofing them to rcflefl differently colour d Rays, occafion in us feveral Senfations of Colour &c. which we attribute to them. See Colour, Vision SSc '

The ObjeBs of the Eye, or of Vifion, are painted on the Retina; tho not erefl.but inverted, according to rhe Laws of Optics This is eafily (hewn from Cartes's Experiment of laying bare the vitreous Humour on the back part of the Eye 3 and clapping over it a bit of white Paper, or the Skin of an Egg, and then placing the fore-parr of the Eve to the Hole of a darkned Room.

By this means is had a pretty Landskip of the ObjeBs a- broad, painted invertedly on the back of the Eye. See Retina.

How, in this Cafe, the ObjeBs which are painted inverted ihould be feen erefl, is matter of Controvcrfy. See See-

INC.

TheSchoolmen diftinguifh ObjeBs into next, proximo which are thofe the Power, or Habit is immediately employ'd on; in which fenfe, Colour is the next ObjeB of Sight : And remote, which are thofe only perceiv'd by means'of the former; in which fenfe, the Wall is the remote Object of Sight, fince we only fee it by means of its Colour £<?c.

Hence it appears that there is a fort of fubo'rdination of ObjeBs. But, note, that a next ObjeB, with regard to a re- mote one, is properly a Subjeft, not an ObjeB. See Sub- ject.

They alfo diftinguifh Objects perfe,vi\\\ct\ are what pro- perly move or affefl our Senfes; and thefe are the fenfible Qualities : And ObjeBs fer Accidens, which are Subflances, and only affect us by being invefted with fenfible Qualities. See Quality and Suestance.

Again, they diftinguifh between Common Objects, which are fuch as affeft divers Senfes, as are Motion, Figure, £J?c. And PriyerOBjECTs, which only affefl one. SeeSENSE.

Object-G&/> of aTelefcope.or Microfcope, is the Glafs placed at that end of the Tube which is next the ObjeB. See Telescope, Microscope, and Glass.

To prove the Regularity and Gninefs of an Otsjucr-GIafs.

Sttike two concentric Lines on a Paper, the one having its diameter the fame with the Breadth of the ObjeB-Glafs^ the other half that Diameter! Divide the inner Circumfe- rence into fix equal parts, and making fix fine fmall Holes therein with a Needle; cover one fide of the Glafs with this Paper. Then expofing it to the Sun, receive the Rays that pafs thro thele fix Holes, on a Plane, at a jufl diftance from rhe Glafs; and by withdrawing or approaching this Plane from or to the Glafs, we fhall find whether the Rays that pafs thro thefe fix Holes, unite exaaiy together at any diftance from the Glafs; if they do, we may be affuredof the Regularity of the Glafs; that is, of its jullForm- and at the fame time we obtain exaaiy the Glafs's Focal Length.

Indeed, there is fcarce any better way of proving the Excellency of an ObjeB-Glafs, than by placing it in a Tube and trying it with fmall Eye-Glaffes at feveral diftant Ob' jeas; for that ObjeB-Glafs that reprefents Obiea s the bnghteft, and moft difti n a, that bears the greateft Aper ture, and moft convex, and concave Eye-Glafs. without colouring or hazinefs, is the bell.

To prove wbetber Objefl-Glaffesoe well center',!.

Hold the Glafs at a due diftance from the Eye; and ob ferve the two refleaed Images of a Candle; where thofe Images unite or coalefce, there is the true Centre If this be in the middle, or Central- Point of the Glafs, 'tis trulv centred. s

Object is alfo ufed for the Matter of an Art or Sci- ence ,5 or that about which it is employ'd : in which Senfe, the Word coincides with SubjeB. See Subject, e?c.

The School-Philofophers diftinguifh divers kinds'of Ob- jeBs in the fame Science, viz