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XCIV. Certain Reafons for a Lunar Atmo - 
fphere\ by Mr. Samuel Dunn. 
Rea f 7 62. y ** T T ^as ^ een a q ue ^i° n which has been 
X I° n g debated among aftronomers, whe- 
ther the Moon has an atmofphere or not ? and, as far 
as I have been able to learn from reading and verbal 
inquiry, the queftion is yet undecided. The bell 
aflronomers I have talked with about this matter, have 
told me they never could difcover any atmofphere 
about the Moon. But this being unfatisfadtory to me, 
I began to conlider with myfelf, by what methods, 
not already ufed, this problem was likely to be lolved ; 
and, among feveral others, thought of one, which I 
don t know that it has been ufed before j namely, by 
amice examination of the two ends of Saturn’s ring, at 
liich time when the planet is on the dark edge of the 
Moon. For the ring of Saturn being of a confider- 
able length, and gradually emerging or immerging 
almoft at right angles, either from or to the dark 
difk of the Moon, the two extremities of this ring, 
and the body of Saturn, being duly obferved, if both 
the preceding and fubfequent extremities of the ring, 
and the body of Saturn alio, fhould happen to appear 
not perfectly defined, exceedingly near to the Moon’s 
dark limb, but perfectly defined a little further there- 
from ; from fuch an appearance, I conclude it might 
be fhongly prefumed, that there is a. lunar atmo- 
fphere j and for want of fuch appearance, that there 
is none, 
Such 
t 
