[ 3^^ 3 
After I had writ thus far I accidentally caft my Eye up- - 
on Ricciolts Treatife of RefraQion, at the end of his 2d, 
•Volume of the Almagefl^ Lib. 10. Se6t. 6. cap. i. J^eji-. 33, 
wherein he fpeaks of our prefent Difficulty ; But to my 
wonder I find him Affert, that he and Father GrimaLdi had 
often taken th& HorizontaUSun and Moons Diameters by 
a Sextant, when to the naked Eye they appeared very 
large; {Grimaldm direfting his Sight to the left edg, and 
Ricciolm to the right, ) and that even by the Inftrument 
they always found the Diameters greater than when 
more elevated, the Sun often flibtending an Angle of al- 
moft a Degree, and frequently 45 Minutes, the Moon 
alfo 38 or 40 Minutes. This is down right contrary to 
the matter of Fafl:, which I hav€ before alkdged, and 
diredly repugnant to the matter of Fa£l afferted by the 
French Abbe in the forecited Journal. Whether of us be 
in the right I leave to Accurate Experiment to determine, 
and fubmit the whole to the Decifion of the llluftriom 
Koyal Society. Only give me leave to add one word a- 
gSLitiA Riccioli, for had his Experiments been Accurately 
profecuted,he fhould have tryed thGm when the Horizontal 
Moon had lookM ten times more large in Diameter than 
ordinary; and then if it be true, that even by an Inftru- 
ment fhe will be found proportionally broader than re- 
ally, fhe fhould fubtend an Angle of 30c Minutes, or 5 
Degrees: for very often I have feen the Moon when fhe 
appeared 1 o times broader than ordinary, which the fmall 
addition of 8 or 10 Minutes to her ufual Diameter will 
never Caule. 
Laftly asan Apology for my reviving this difquifition 
to that Noble Company of Engli/h Philofophers, I fhall 
only intimate the words of the forementioned Abbe^ Let- 
ter. Pavr la Raifon de cette Apparence^ & de la tromperie 
de nos Sens ^ je la t tens plus Difficile a trouver, que les plus 
grands Equations £ Algehre,& qu and vousy aurez hi en fenfe^ 
vo'ds rn Obltgerez de nr en dire vojtre Sentement, &cc. 
After 
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