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Show 0f Seeing. 90+ Book III. and fewer lucid Raysh ( not difiraéting each other, are tranfmitted to the Paper, whence cometh a more clear reprefentation of the Obieét Upon it. > . , m maimcr The whole image of a thing tranfmitted from any darkened, point of a mm" Image isob- Convex-Glafs into a Paper, is obfcured Without any change of its miantity 333.13:pya 0,. Figure, by reafon the {pecies of the whole Obielét Ihath its1fCone rendred iiomwf 1: Emu. more acute againfl every pomt of the Gla s ,_ iti w )lC'l it is a o everted, and {.0 far extended» till all its points are conioyned With the Homogeneous Rays of any other everted Species, f0 that they agree With each otherin fome common Bafis of the Paper : VVhence it followeth that there are fo man diltiné‘t evertcd Bafes of the Image, placed over each other, and difpofed after the fame manner, as there are found divers points of Everfion and Inter- feéiion in the Convex-Glafs, ( which is not found in a hole free from it) and is caufed by the refraction of Rays in aConveX-Clafs. . . a rilibicOb- This may be farther illuftrated by this inflance, That an Object emittetli li""‘""‘,"‘,, Rays from all its points into a Convex-Glafs, and maketh direét Pyramids iitiiyririu m, at every point of it', but ifthe hole be naked, as divelted of any Glafs, the points will make their progrefs fo direé‘tly, that the Angles of their Vertices may become equal on each fide; f0 that everted Pyramids, can no where in concurr or meet, as all to obtain one common Bafe : But ifany point he intercepted iria Convex-Glafs, the whole Bafe of the Picture mull be fomc. what darkened; and ifmore points of tlic Glafs be obfcured, the common Bale ofrhe Image, belonging to the Object, will be more eclipled; Audthe reafon, ( as I humbly conceive) may be this, That the Whole Image of the Objt'a doth emit Rays into one point of the Convex-Glafs , after which, all Rays interfeéi each other, and make their progrefs in everted politicos; to that one Ray follows another, and afterward pafleth into one Ray, and the femblance ofthe whole Object is painted upon the Bafe in an everted poliure', Hence it may be inferred, that thcfame Object agreeth in a point of a Con\‘ex-Glal‘s, and afterward parteth in an everted courfe, according to thePyiamid made in the Safe, which is intercepted in a point of an opace Body; fo that a line drawn from a common Bafe, doth interfeét an everth Pyramid, after the fame manner placed upon the Bafe ofthe Pyramid, becaufe the Rays coming from the point ofa Vertex, arc traiifinittcd to a point ofthe ConvexSurface ofthe Glafs, and are like as equal both in refpeét to theirlrmgthimd refraction, and do intend each other by a mutual fuper-impofition. Hence it may be made evident by Reafon and Experience, that every vilible point doth emit a radious Cone to the furface of all the Glafs; the Bafe of which Cone is placed in the ambient part of the Glafs, and the Vertex of the Ray in the vilible point, and the whole Pyramid is reftaéled in the Glafs, and all the Rays being trajcé'red the Glafs, have an inclination and tendency to each other, till they feem according to fenfe to agree, and 35 it were concenter in one point. tumu- [Kat's iiihiiiiiiio $331233; igfi‘z‘gfl fame;- " Ifa viiible point emit a Cone, in whofe conick Surface many intermfdl' al Rays do (him: through the whole furface of the Glafs (whether it be Plane 01‘ Convex) they are all refracted into one point; whence it cometh,thi |t the Vlftble point is fo clearly and lively reprefented by the conjuncti on of many Rays in a Cone 3 hence the lenticular Convex-parts of very little Sphazres, i'eprefent very fmall Images ofvifible Objeéts after a clear manner, by reafon many vifible lpecies are united in one point,and the Pyramids flCll‘tC, then they are in the fegments of greater Sphaeres ; as are render more alfo becaufe the Bates are rendrcd more neat to the 012.1%, and fo are endued With more M Book Ill. 0f Seeing. {bong Rays, and from hence it is, that ifone point of the Chi]; be obt‘cm-cd and its Ray eclipfed, yet notwithflanding the viiible point may be dike-rim}, by other Rays, by reaibn the whole Objeét is tranfmitt ed by a right pro~ grefl- of the Rays into every point of the Glafs 5 and from this afterward, a Refraction and everth pofition is made of united Rays, painting the Obie-6ft upondrhe oppofite Paper, as a Bafe common to tliC everted Cortes, and Py. mm s. The former Difco‘urfesof experimental Opticlts, drawn from Art, hold lin‘nral clingreat correfpondence with things ofnaturc, and d: much c ntribtite to the Til"? " better undetflandingofthe manner ofSight, as natural Operations are illu- by"? Lin {hated by artificialinflances 5 f0 that the many faid Hl‘POfltelEs, lullanccs. and Experiments are fitly applicable to the parts and Sight of the Eye. The hole made through a Wall into a dark Chamber, fomewhat refembles Attaicmzi: the Pupil (leading into the more inward recefles ofthe Eye) as it is receptive WM" " of Images, {treaming from a viflble Object; and the Rays coming in direét [inhibit lines interfeét each other, before they enter the perforation ofthe Wall, as Eliziigjl'u‘ Well as the lucid beams admit a decutfation, before they arelreceived into the Pupil; and the progrefs of the Rays is made in a Pyram idal Figure, as they are endqu with 3 Cone, where they are tranfi nitted through the Forum: ofthe Wall ; after the fame manner the vifibl e Rays are more enlarged toward the Objet‘}, from whence they are reflcéled, and after into a Cone, where they are immitted into the hole ofthe ward are lefleiied liq/ea. If the hole of the Wall be too large, the Objec t is confu fedly paint h hole ""197 ?" . , , upon the Paper, by reafon the beams of light beingr . rcuil r too bright, do oblcu re thctrmizci~ the Colour and Figure of the Image, which haPpens in like manner in 1121- Ziriiigii rure,wherein the Species is clothed with over-l ucid Rays, tranfiiiitted throngh too open a Pupil ; whereupon the vilible femblances are eclipf ed, as the dark chamber ofthe Eye are reached too bright, to that the Sight is confounded by over-much l ight. The Paper placed at a due diflance from the hole of , the {hape and colour of an Objeét, pailing throug the Wall, receiiketh Tthaptr h the Forearm of the duetlillante WW" Wall. from the Eye, l'Cmeblcth The Retina is not unlike the faid Paper, as the Image being emitted from KIN-WNany point ofan Object, is carried thrmigh the Pupil of the Eye, and at laft imprinted on the Retina. , Every point ofa Convex-Glafs ( covering the hole of the Wall ) receiveth the Cone of the Objeét,whereby it is more clearly feen, and as the Rays grow more united in the Surface of a Convex~Clafs,th ried to the furfacc of the Paper, where the Colou ey are trajeéted and carr and Figure of the Objea: may be more clearly difcemed. The Crif'calline Humor of the Eye hath fame likenefs with a Convexlafs, as it is tranfparent and endqu with a parabolical Figure , in which the Vifible Rays arayed With Light, are more contra cted, whereby the Image 0‘ the Object is painted more lively upon the Raina : And alfo an interfeétton of the Rays is made, as well in Criftalline from the Pupil of the Eye )' as in the Convex-Gla Humor ( feared not far fs placed near the hole of the Wall. Ahole open and uncovered, giveth a faint repref entation of an Obieft; Quffi'gjj‘r‘i-‘ {it » . u the addition of a Convex-Glafs rendreth the Imag e more clear and di- givcthan ob"151' Upon the fin-face of the Paper: after the fame manner fture reti‘ina (Iconceive ) it hl.:n(e of an Would be in the Eye, ' if the Criftalline Humor had been deficient, whereb y Ob' ‘il‘ the {Emblartce of the Objee‘t,being appar'allel'd with Rays ofLight ,and tranf- thong mitted i 5. |
