After the sun’s broad beams have tired the sight, the moon with more sober light charms us to descry her beauty, as she shines sublimely in her virgin modesty. There is always a most fascinating freshness in the first sight of the new moon. The superstition of centuries adds to this charm. Why boys and girls like to turn over a coin in their pocket at this sight one cannot tell: yet it is done. No young lady likes to look at the new moon through a pane of glass. And farmers are always confident of a change of weather with a new moon: at least in bad weather they earnestly hope for it.
But, banishing all superstition, we welcome the pale silver sickle in the heavens, once more appearing from the bosom of the azure. And no language can equal these beautiful words of the youthful Shelley:—
“Like the young moon,
When on the sunlit limits of the night
Her white shell trembles amid crimson air,
And while the sleeping tempest gathers might,
Doth, as the herald of his coming, bear
The ghost of its dead mother, whose dim form
Bends in dark ether from her infant’s chair.”
That is a more charming way of putting the ordinary expression, “the old moon in the new moon’s arms.” We are regularly accustomed to the moonshine, but only occasionally is the earthshine on the moon so regulated that the shadowed part is visible. This is not seen at the appearance of every new moon. It depends upon the positions of the sun and moon, the state of the atmosphere, and the absence of heavy clouds. I never in my life saw the phenomenon so marvellously beautiful as on May 7th, 1894, at my manse in Strathmore. I took particular note of it, as some exceedingly curious things were connected with it.
At nine o’clock in the evening, the new moon issued from some clouds in the western heavens, the sun having set, about an hour before. The crescent was thin and silvery, and the outline of the shadowed part was just visible. The sky near the horizon was clear and greenish-hued. As the night advanced the moon descended, and at ten o’clock she was approaching a purple stratum of clouds that stretched over the hills, while the position of the sun was only known a little to the east, by the back-thrown light upon the dim sky. Through the moisture-laden air the sun’s rays, reflected by the moon, threw a golden stream from the crescent moon, for the silvery shell became more golden-hued.
The horns of the moon now seemed to project, and the shadowed part became more distinct, though the circle appeared smaller. By means of a field-glass I noticed that this was extra lighted, with points here and there quite golden-tinged. The darker spots showed the deep caverns; the brighter points brought into relief the mountain peaks.
Why was the surface brighter than usual? I cannot go into detail about the phases of the moon; but, in a word, I may say that, while the sun can illuminate the side of the moon turned towards it, it is unable to throw any light on the shadow, seeing that there is no atmosphere around the moon to refract the light.
If we, in imagination, looked from the moon upon the earth, we should see the same phases as are now noticed in the moon; and when it is just before new moon on the earth, the earth will appear fully illuminated from the moon. We would also observe (from the moon) that the brightness of the illuminated part of the earth would vary from time to time, according to the changes in the earth’s atmosphere. More light would be reflected to the moon from the clouds in our atmosphere than from the bare earth or cloudless sea, since clouds reflect more light than either land or sea. Accordingly, we arrive at this curious fact—that the extra brightness of the dark body of the moon is mainly determined by the amount of cloud in our atmosphere.
Accordingly, I concluded that there must be clouds to the west, though I could not see them, which reflected rays of light and faintly illuminated the shadowed part of the moon. It had become much colder, and I concluded that during the night the cloud-particles, if driven near by the wind, would condense into rain. And, assuredly, next morning I was gratified to find that rain had fallen in large quantities, substantiating the theory.
There is much pleasure in verifying such an interesting problem. The dark body of the moon being more than usually visible is one of our well-known and oldest indications of coming bad weather. And at once came to my memory the lines of Sir Patrick Spens, as he foreboded rain for his crossing the North Sea:—