“Then your old friend Riccioli certainly did not bestow the appellation.”
“No, it was one of his more fanciful, or, if you prefer, more poetical predecessors, perhaps the same who imagined the ‘Marsh of a Dream.’”
“Oh, that gives me another reason to think of him with admiration and gratitude. He, at least, had a soul that rose above mere prosaic facts.”
“Perhaps. But do not think too lightly of the facts of the moon. After all the human mind must base itself upon the solid ground of fact. Without that we should become mere dreamers, and be suited only to inhabit your favorite ‘Marsh.’”
“The other mountain ranges of which I have spoken,” I continued, “are faintly distinguishable eastward from the Mare Serenitatis. They are the Apennines, the Caucasus, and the Alps. But perhaps we had better turn at once to photograph No. 8 where they are much more clearly seen, because the sunrise there has advanced a couple of hundred miles farther east.”
“But, dear me, how slowly the sun rises on the moon! Was this photograph taken a day later than the other?”
No. 8. August 31, 1903; Moon’s Age 9.22 Days.
“Almost exactly two days later. When it was made the moon was nearly nine and a quarter days old, and its age at the time No. 7 was made was only seven and a quarter days. But, owing to the effects of libration, an explanation of which I have put into a note for your private reading when you feel like it, [see p. [57], footnote], the difference of phase amounts to less than two days. You are right, however, in remarking that sunrise is a very slow process on the moon. It requires about two weeks to pass from the western side of the moon to the eastern side, and both day and night at any point on the moon last about a fortnight. This results from the fact that, as I have told you, the moon does not turn rapidly on its axis like our own globe, but keeps always the same side directed toward the earth. Accordingly, a lunar day and night are together about a month long.”
“And was it so when, as I must persist in believing, there were inhabitants on the moon?”