I7« On the Queftlon, whether the Sun, Moon, and 



Thoughts on the Lunar Atmofphere*, 'and T. Mayer's 

 Proofs that the Moon has no Atmofphere f : but, without 

 tranfcribing them, I fhall here give a fliort view of them, 

 and in the fame order as I have related the grounds on which 

 the opinion of the lunar atmofphere is founded. 



In regard to the bright ring (i) which has appeared round 

 the moon during total folar eclipfes, it is evident that, even 

 if we aclmit that the moon has an atmofphere, it mufl; have 

 been occafioned by its refraftion. But experience has fhown 

 that bright rings of the like kind are produced around all 

 opaque bodies when they are placed oppofite the fun or any 

 ftrong light. This was found to be the cafe by De la Hire, 

 who oppofed this circumftance to the opinion of Louville, 

 who was a ftrenuous advocate for the lunar atmofphere. For 

 this purpofe he took an unpoliflitd globe of ftone, and, placing 

 it bet^veen his eye and the fun, faw the interior edge of the 

 ring, which was formed around it, broken and uneven, as 

 Louville had feen the interior part of the ring around the 

 moon. A like experimeilt was made by De I'lfle junior. 

 He caufed the rays of the fun to pafs through a fmall hole 

 into a darkened room ; held a circular piece of lead between 

 him and the fun ; and obferved, on a fheet of white paper, 

 that the fhadow of the lead was evidently furrounded by a 

 Juminous ring|. John Caffini explained the ring feen 

 around the moon during total eclipfes of the fun from the 

 folar atmofphere; and this was carried ftill farther by De 

 Plantade. But this explanation is not neceffary, as it ap- 

 pears that the whole phenomenon may be explained as well, 

 if not much better, from refraftion. Du Sejour, however, 

 js of opinion, that refraftion of the fun's rays at the moon's 

 jimb cariubt be admitted unlefs we firtl admit a lunar atmo- 

 fphere : and he {hows, from Short's Obfervation of the Solar 

 Eclipfe in 1764, that the vefraftion of the fun's rays which 

 touched the moon's limb amounted to 4^^''. 



* Qedanken lilier die atmofphure des mondes, Ldpftc 1746, 4to. 



t Kofmologifche nachrichten und fammlungen aiif das jahr, 1748. 

 yiurn. 1750, 4to. p. 397. 



J See his Paper on the Atmofphere of the Moon, in the Mituoirfs de 

 }i'4cinlemie dts Sciences f9r 1715. Ffiris 1718; p. 147, 



One 



