Solar Eclipse. 293 



" J'ai decouvert vers le milieu de Teclipse, sur la surface de 

 la lune, comprise entre les comes du soleil, des rayons de 

 lumiere rouge*," Sfc. 



A general conclusion from these appearances is, that " they 

 are flashes of lightning, such as a spectator in the moon would 

 see in our earth if its whole hemisphere were interposed be- 

 tween him and the sunt. Hence it is inferred, that " the 

 moon has an atmosphere similar to ours, wherein vapours and 

 exhalation may be supported, and furnish materials for clouds, 

 storms, and tempests]:." 



Of these phenomena, another explanation has been given, 

 in which it is assumed, that cavities in the body of the moon, 

 acting as concave mirrors, reflect the solar light obliquely to 

 the eye of the observer, and that the progressive motion of the 

 planet in its orbit, by constantly changing the position of the 

 reflecting surfaces, in relation to the line of vision, causes the 

 ray:s thus suddenly turned from their former direction, to appear 

 in momentary streams or coruscations of light §. 



Without insisting on the numerous objections which are 

 opposed to the former of these hypotheses, such as the casual 

 nature of the occurrence on which it rests, the small space over 

 which its influence could be visible, the weakness of the illumi- 

 nation which it could produce, as compared with the extent, 

 duration, and brilliancy of the effects observed — the very cause 

 assumed would remove the possibility of viewing the effect 

 from which it is inferred. Granting that such an atmosphere 

 as is contended, does actually surround the moon, an observer 

 on the earth would not, in that case, be able to discern the 

 lightning, since the whole mass of vapour must necessarily 

 intervene, and conceal it from view ; as, by the laws which 

 regulate its motions, the flash would pass between the surface 



• Mem. de I' Acad, des Sciences, 1748, page 56. 

 t Phil. Trans., as quoted above. 

 I Long's Astronomy. 



§ Astron. de La Lande ; M. De I'sle, Memoirea pour servir H I'Hist, de 

 I'Aitron.y 1733, page 248 ; and Mem, de I' Acad, des Seientes. 

 Vol. XI. X 



