LUNAR CELESTIAL PHENOMENA.

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light outside of the moon during totality is sunlightrefracted by the moon, simply because the part where

one observation, I had worked myself up to a belief that the globesof Saturn and Jupiter were more affected under occultation thancould be assigned to the inflection of their light in passing by thelunar surface ; and I also thought that I had seen the satellitesof Jupiter change their figure at the instant of immersion. Thusprejudiced, so to say, I prepared to establish the point by theoccultation of the 1st of June, 1831, and certainly observed itunder a train of favouring circumstances ; but my result, as statedin the second volume of the Astronomical (Society's Memoirs, p. 37,is this: Although the emersions of the satellites were perfectlydistinct, they were certainly not so instantaneous as those of thesmall stars, which I think was owing more to light than disc.Jupiter entered into contact rather sluggishly; but though thelunar limb was tremulous from haze, there was not the slightestloss of light. Faint scintillating rays preceded the emersion, whichwas so gradual, that, as the planet reappeared, the edge of themoon covered it with a perfectly even and black segment, whichcut the belts distinctly, and formed clear sharp cusps, slowlyaltering until the whole body was clear. There was no appearanceof raggedness from lunar mountains, and Jupiter ’s belts weresuperbly plain while emerging; but there was not the slightestdistortion of figure, diminution of light, or change of colour. . . .Schroter concluded that there existed a lunar atmosphere, but heestimated it to be only 5,742 feet high ; and Laplace considered itas being more attenuated than what is termed the vacuum in anair-pump. The slowness of the moon’s motion on its axis mayaccount for such result.” (There is, however, no basis for thissupposition.) . . . “ MM. Miidler and Beer , whose selenographicalresearches have been carried to an unprecedented extent, arrive atthe conclusion that the moon is not without an atmosphere, butthat the smallness of her mass incapacitates her from holding anextensive covering of gas, and they add, ‘ it is possible that thisweak envelope may sometimes, through local causes, in somemeasure dim or condense itself,’ the which would explain some ofthe conflicting details of occultation phenomena.”