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ANNUAL MOTION.
The ship was much delayed in the Region of the Calms, as it is called; that is, near the equator.

After a while the astronomical dialogue was resumed.

“Well, James, look now at your twinkling friends, and tell where you are.

I suppose by the North Polar star resting upon the waters to the north, that we must be now nearly on the top of the hill, by the equator.

We are so, my lad. But what time did the sun rise this morning?

At six, and it set at exactly six this evening.

Do you know what day of the month it is?

The twenty-third of September.

Have you ever observed the sun to rise and set at six o’clock before, on the voyage?

No, father.

Well, then, you will recollect hereafter that[Pg 20] you were upon the equator on the twenty-third of September, when there was equal day and night. But did you not know of equal day and night at home?

Yes; about half-way between winter and summer.

Just so; that is, at the end of September.

Why should it be so there in England and here too?

We will try and find out. I think I have pointed out to you the Pleiades.

I know them well. They are in the Bull cluster.

There happens to be a band of twelve constellations forming a broad circle of the heavens.

Is that what is called the Signs of the Zodiac?

The same. Can you repeat them?

Yes, father. Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, Virgo the Virgin, Libra the Scales, Scorpio the Scorpion, Sagittarius the Archer, Capricornus the Goat, Aquarius the Water-bearer, Pisces the Fishes.

Over there to the eastward is one of these that rose as the sun was setting. The sun is seen opposite one or other of the twelve constellations in each month of the year. It is observed, for instance, to rise each morning for a month in the constellation of the Ram, and for the next month in the Bull.

How can it be among those stars when you say they are so much farther off?

By saying it is in such a constellation, I[Pg 21] mean that it is in a line between us and that cluster of stars.

Why, then, the sun appears to go a journey between the stars and us for a whole year. Then it will rise in the Ram twelve months after it had been seen opposite that constellation. I wonder how this can be. Did you not say, father, that neither the stars nor the sun really moved?

I did.

Well, then, it must be either the stars turning about the sun, or the sun taking an annual trip about them, and yet the stars do not move, and the sun does not.

Let us leave the sun and his trip for a little, while we have another talk about the stars.

Notice that red star just rising there on the larboard side.

I have it, father.

As I want you to remember it, take my pocket-book and mark off with the pencil a picture of the star and its four neighbours, putting a cross under the one that has just risen.

There it is,—the under one of this cluster I have sketched. I shall know him again.

Now, then, you must go below, and resume your observations to-morrow. I took the exact time—seven p.m.—when you saw the star rise. You must look for it at seven to-morrow evening.”

At four minutes before seven the next night, up rose the pretty object, and stole a glance at the boy across the ocean.

[Pg 22]“Father, father! it’s up, it’s up!” sang out the happy lad.

His father looked at his watch, and said—

“Your star did not come to his time. It was four minutes to seven o’clock when he appeared, and that is four minutes too soon.

How is that, father? I must ask you, for it is of no use asking the star.

Perhaps you will still wonder when I tell you that to-morrow evening it will be eight minutes to seven before it gets up at this place.

Why, this is like the sun among the stars—always getting out of his place. But the sun gets right after a year.

Do you think our star will ever get right—so as to rise at seven some other evening?

I do not know, father.

If it rise four minutes earlier every day when will it be an hour earlier?

In half-a-month; and twenty-four hours earlier in twelve months. But that is the time when it will be visiting at night again.

So you have ascertained that the stars go an apparent journey round the earth in a year; like as the sun takes a year to go his apparent course among the stars.

Then both must have the same cause. As I found the daily motion of the stars was owing to the real daily motion of the earth, I suppose this yearly motion of the stars must be caused by some yearly motion of the earth.

Either the sun turns round the earth once a year, or the earth does round the sun.

[Pg 23]Well, father, the sun appeared also to turn round the earth once a day. I do not think I could run round the deck in two minutes while I am two hours doing it. Then, as I am satisfied it did not have a daily motion, I am the more disposed not to trust to this apparent yearly motion. It is more likely, too, that the little world should run round the great sun, than that the great sun should revolve round the earth.

I perceive you are as settled upon the annual or yearly motion as you were upon the diurnal or daily revolution.”

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