CHAPTER XVII

THE OLD MOON IN THE NEW MOON'S ARMS

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:--

"I saw the new moon late yestreen

Wi' the auld moon in her arm;

And if we gang to sea, master,

I fear we'll come to harm."

This lunar indication, then, has a sound physical basis, showing that near

the observer there are vast areas of clouds, which are reflecting light

upon the moon at the time, before they condense into rain by the chilling

of the air. According to the old Greek poet, Aratus: "If the new moon is

ruddy, and you can trace the shadow of the complete circle, a storm is

approaching."

Meteorology; or, Weather Explained · 第 17 / 35 章