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will hokl ili lookistg at thc Sun through very darlc Glafles, which render tbr-Sight thereof as inoffensive to the Eyc, as that; of a Green Field ; but per-;haps he will then siy, that this other Reason hold;, which is, Secondly, Thunthe greater imaginary Distance at which we think the Moon near the Hori-zon, than when more Elevated, makcs us Contemplate her as if really Ihewas so, d/j'. with Ample Pupils, Cc. But this I have fuffieiently overthrownin my Remarks against Des Cartcs Therefore I paß ic pver, only liibjoyn-ing, that if there were any thing in this Surmise, my-thinks thc HorizontalMoon should bc fansied nigher to us than farther from us ; for if we aivfor trying Natural Thoughts, let us take Children to determino the Matter,vvho are apt to think, that could they go to the edge of that space that bouncvtheir Sight, they should be able (as they call it) to touch thc Slcy ; and pon-.lequently the Moon sccms then rather nigher to us than farther from us.

After I had writ thus far, I accidcntally cast my Eyc upon Rjccioii's Trta-tise of RjefrnBion, at thc end of his second Volume of the Almngeß , Lib.'ia.Sccl. 6. Cup. i. Queß. 13. wherein he speaks of our prescnt diificulty ; but tomy wonder I find him assert, That he and Father Grimaldi had often taken•the Horizontal Sun and Moon’s Diameters by a Sextant, when to the naked'Eye they appeared very large ; ( Gümnldus directing his Siglit to the lest edge,and RJccioha to the right) and that even by the Instrument they alwaysfoundthe Diameters greater than when morc Elevated, the Sun often sobtending ar»Angle öf almost a Degree, and frequcntly 45- Minutes, the Moon also 38-or 40 Minutes. This is down-right contrary to the matter of Fact whichI have before alledged, and directly repugnant to the matter of Fact afl'ertedby the forcmention’d French Abbe Whither of us be in the right I leave toto accurate Experiment to determine, and sobmit the whole to the Decisionof the lllustrious J\oynt Society. Only give rae leave to add one word : againstRjccioli, for had his Experiments been accurately prosecuted, he should have;tried them when thc Horizontal Moon had look’d 1 o times more karge inDiameter than ordinary ; and then if it be true, that even by an InstrumentIhe will be found proportionaliy broader than really, she should Subtend anAngle of 300 Min. or 5 Deg. for very often I have seen the Moon whenIhe appear’d 1 o times broader than ordinary, which the finali Addition of &or 10 Min. to her usoal Diameter will ncvev cause. ■

2.. I dilcoursed of this Appearance near 40 yeavs ago with Mr. Frßer, thenProfessor of Aßrommy in Grcsham College , who did then affine nie, (from hisown Observation I soppose) that the apparent Magnitude taken by In-struments, (however thc fancy may apprehend it) is not greater at the Hori-zon than when higher. Mr. Coswcll affirms the säme thing ; And I donot doubt but the thing is so : For though Resraction near the Horizon alterthe Altitude of the thing seen ; yet it cannot alter the-Azimuth at all. Forlincc this eqdWly respects all Points of the Horizon ■; lct tlie Resraction bewhat it will, the whole Hofi/on can be but a Circlc : so that there is noroom for the ’breadth of a thing ("as to ,the Angle at. the ,Ey.e). to lie madegreater, whatever its tallness may Ahe Resraction not eqpally aftecting allparts in thc Circles oT Altitude.) Nor is there any Reason,. why tliiy- (lipuldVoll. G g rather

T/h’/ Thtnorncnon confidere lby Dr. Wall'Ibid. f. Z2>

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