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LUNAR CELESTIAL PHENOMENA.

a ring of light close to the moon’s edge, while theparts nearer the sun’s edge would form outer andbrighter parts of the ring of glory round the moon.A very shallow lunar atmosphere indeed would sufficeto bring the parts close to the edge of the sun’s discinto view. It was, indeed, once supposed that thesierra of red light seen round the moon’s disc duringtotal eclipse (that ring of red light which Mr. Lockyerso strangely supposed that he had discovered in 1868)was produced by the refraction of the sun’s light bythe moon.* We now know that no part of the

* Thus Admiral Smyth wrote in 1844 :—“ The red flames orprotuberances of light, observed during total eclipses, and so cor-rectly noted by the Astronomer Royal and Mr. Baily duringthat of July 1842, seemed to be attributable to an atmosphericeffect, albeit there may be no distinguishable atmosphere. Solong ago as 1706, Captain Staunyan, at Berne, observed of the sun,‘ that his getting out of the eclipse was preceded by blood-redstreaks of light from the left limb, which continued not longerthan six or seven seconds of time.’ On this Flamsteed remarksin a letter to the Royal Society : ‘ The Captain is the first man Iever heard of that took notice of a red streak of light precedingthe emersion of the sun’s body from a total eclipse ; and I takenotice of it to you, because it infers that the moon has an atmo-sphere ; and its short continuation of only six or seven seconds oftime tells us that its height is not more than the five- or six-hundredth part of her diameter.’ This phenomenon was againnoted during the total eclipse of the sun in April 1715, by CharlesHayes, the author of A treatise on Fluxions, who states in hisphilosophical dialogue Of the Moon that there was a streak of‘ dusky but strong red light ’ preceding the sun’s reappearance.There is much uncertainty, however, in all these observations,from their being liable to so many conditions of place, weather,instrument, and wind.” I quote the remainder of Admiral Smyth ’sremarks as bearing importantly on our subject“ From more than