PART II

THE SKY

EVERY FAMILY A "STAR CLUB"

The best family hobby we have ever had is the stars. We have a star club with no dues to pay, no officers to boss us, and only three rules:

1. We shall have nothing but "fun" in this club--no hard work. Therefore no mathematics for us!

2. We can't afford a telescope. Therefore we must be satisfied with what bright eyes can see.

3. No second-hand wonders for us! We want to see the things ourselves, instead of depending on books.

You can't imagine what pleasure we have had in one short year! The baby, of course, was too young to learn anything, and besides he was in bed long before the stars came out. But Ruth, our seven-year-old, knows ten of the fifteen brightest stars; and she can pick out twelve of the most beautiful groups or constellations. We grown-ups know all of the brightest stars, and all forty-eight of the most famous constellations.

And the whole time we have given to it would not exceed ten minutes a day!

And the best part is the _way_ we know the stars. The sky is no longer bewildering to us. The stars are not cold, strange, mysterious. They are friends. We know their faces just as easily as you know your playmates.

For instance, we know Sirius, because he is the brightest. We know Castor and Pollux, because they are twins. We know Regulus, because he is in the handle of the Sickle. And some we know by their colours. They are just as different as President Taft, "Ty" Cobb, Horace Fletcher and Maude Adams. And quite as interesting!

What's more, none of us can ever get lost again. No matter what strange woods or city we go to, we never get "turned around." Or if we do, we quickly find the right way by means of the sun or the stars.

Then, too, our star club gives us all a little exercise when we need it most. Winter is the time when we all work hardest and have the fewest outdoor games. Winter is also the best time for young children to enjoy the stars, because it gets dark earlier in winter--by five o'clock, or long before children go to bed. It is pleasant to go out doors for half an hour before supper and learn one new star or constellation.

Again, it is always entertaining because every night you find the old friends in new places. No two nights are just the same. The changes of the moon make a great difference. Some nights you enjoy the moonlight; other nights you wish there were no moon, because it keeps you from spying out some new star. We have a little magazine that tells us all the news of the stars and the planets and the comets _before_ the things happen! We pay a dollar a year for it. It is called the _Monthly Evening Sky Map_.

When we first became enthusiastic about stars, the father of our family said: "Well, I think our Star Club will last about two years. I judge it will cost us about two dollars and we shall get about twenty dollars worth of fun out of it." But in all three respects father was mistaken.

Part of the two dollars father spoke of went for a book called "The Friendly Stars," and seventy-five cents we spent for the most entertaining thing our family ever bought--a planisphere. This is a device which enables us to tell just where any star is, at any time, day or night, the whole year. It has a disc which revolves. All we have to do is to move it until the month and the day come right opposite the very hour we are looking at it, and then we can tell in a moment which stars can be seen at that time. Then we go down the street where there is a good electric light at the corner and we hold our planisphere up, almost straight overhead. The light shines through, so that we can read it, and it is just as if we had a map of the heavens. We can pick out all the interesting constellations and name them just as easily as we could find the Great Lakes or Rocky Mountains in our geography.

We became so eager not to miss any good thing that father got another book. Every birthday in our family brought a new star book, until now we have about a dozen--all of them interesting and not one of them having mathematics that children cannot understand. So I think we have spent on stars fifteen dollars more than we needed to spend (but I'm glad we did it), and I think we have had about two hundred dollars worth of fun!

Yes, when I think what young people spend on ball games, fishing, tennis, skating, and all the other things that children love, I am sure our family has had about two hundred dollars worth of fun out of stars.

And there is more to come!

You would laugh to know why I enjoy stars so much. I have always studied birds and flowers and trees and rocks and sh.e.l.ls so much that I was afraid to get interested in stars. I thought it wouldn't rest me. But it's a totally different kind of science from any I ever studied! There are no families, genera, and species among the stars, thank Heaven!

That's one reason they refresh me. Another is that no one can press them and put them in a herbarium, or shoot them and put them in a museum. And another thing about them that brings balm to my spirit is that no human being can destroy their beauty. No one can "sub-divide" Capella and fill it with tenements. No one can use Vega for a bill-board. Ah, well! we must not be disturbed if every member of our family has a different point of view toward the stars; we can all enjoy and love them in our own ways.

How would you like to start a Star Club like ours? You ought to be able to persuade your family to form one, because it need not cost a cent.

Perhaps this book will interest them all, but the better way is for you to read about one constellation and then go out with some of the family and find it. This book does not tell about wonderful things you can never see; it tells about the wonderful things all of us can see.

I wish you success with your Star Club. Perhaps your uncles and aunts will start clubs, too. We have three Star Clubs in our family--one in New York, one in Michigan, and one in Colorado. Last winter the "Colorado Star Gazers" sent this challenge to the "New Jersey Night-Owls:" "_We bet you can't see Venus by daylight!_"

That seemed possible, because during that week the "evening star" was by far the brightest object in the sky. But father and daughter searched the sky before sunset in vain, and finally we had to ask the "Moonstruck Michiganders" how to see Venus while the sun was shining. Back came these directions on a postal-card: "Wait until it is dark and any one can see Venus. Then find some tree, or other object, which is in line with Venus and over which you can just see her. Put a stake where you stand. Next day go there half an hour before sunset, and stand a little to the west. You will see Venus as big as life. The next afternoon you can find her by four o'clock. And if you keep on you will see her day before yesterday!"

That was a great "stunt." We did it; and there are dozens like it you can do. And that reminds me that father was mistaken about our interest lasting only two years. We know that it will not die till we do. For, even if we never get a telescope, there will always be new things to see. Our club has still to catch Algol, the "demon's eye," which goes out and gleams forth every three days, because it is obscured by some dark planet we can never see. And we have never yet seen Mira the wonderful, which for some mysterious reason dies down to ninth magnitude and then blazes up to second magnitude every eleventh month.

Ah, yes, the wonders and the beauties of astronomy ever deepen and widen. Better make friends with the stars now. For when you are old there are no friends like old friends.

THE DIPPERS AND THE POLE STAR

I never heard of any boy or girl who didn't know the Big Dipper. But there is one very pleasant thing about the Dipper which children never seem to know. With the aid of these seven magnificent stars you can find all the other interesting stars and constellations. So true is this that a book has been written called "The Stars through a Dipper."

To ill.u.s.trate, do you know the _Pointers_? I mean the two stars on the front side of the Dipper. They point almost directly toward the Pole star, or North star, the correct name of which is Polaris. Most children can see the Pole star at once because it is the only bright star in that part of the heavens.

But if you can't be sure you see the right one, a funny thing happens.

Your friend will try to show you by pointing, but even if you look straight along his arm you can't always be sure. And then, if he tries to tell you how far one star is from another, he will try to show you by holding his arms apart. But that fails also. And so, we all soon learn the easiest and surest way to point out stars and measure distances.

The easiest way to tell any one how to find a star is to get three stars in a straight line, or else at right angles.

The surest way to tell any one how far one star is from another is by "degrees." You know what degrees are, because every circle is divided into 360 of them. And if you will think a moment, you will understand why we can see only half the sky at any one time, or 180 degrees, because the other half of the sky is on the other side of the earth.

Therefore, if you draw a straight line from one horizon, clear up to the top of the sky and down to the opposite horizon, it is 180 degrees long.

And, of course, it is only half that distance, or 90 degrees, from horizon to zenith. (Horizon is the point where earth and sky seem to meet, and zenith is the point straight over your head.)

Now ninety degrees is a mighty big distance in the sky. The Pole star is nothing like ninety degrees from the Dipper. It is only twenty-five degrees, or about five times the distance between the Pointers. And now comes the only thing I will ask you to remember. Look well at the two Pointers, because the distance between them, five degrees, is the most convenient "foot rule" for the sky that you will ever find. Most of the stars you will want to talk about are from two to five times that distance from some other star that you and your friends are sure of.

Perhaps this is a little hard to understand. If so, read it over several times, or get some one to explain it to you, for when you grasp it, it will unlock almost as many pleasures as a key to the store you like the best.

Now, let's try our new-found ruler. Let us see if it will help us find the eighth star in the Dipper. That's a famous test of sharp eyes. I don't want to spoil your pleasure by telling you too soon where it is.

Perhaps you would rather see how sharp your eyes are before reading any further. But if you can't find the eighth star, I will tell you where to look.

Look at the second star in the Dipper, counting from the end of the handle. That is a famous star called Mizar. Now look all around Mizar, and then, if you can't see a little one near it, try to measure off one degree. To do this, look at the Pointers and try to measure off about a fifth of the distance between them. Then look about one degree (or less) from Mizar, and I am sure you will see the little beauty--its name is Alcor, which means "the cavalier" or companion. The two are sometimes called "_the horse and rider_"; another name for Alcor is Saidak, which means "the test." I shall be very much disappointed if you cannot see Saidak, because it is not considered a hard test nowadays for sharp eyes.

Aren't these interesting names? Mizar, Alcor, Saidak. They sound so Arabian, and remind one of the "Arabian Nights." At first, some of them will seem hard, but you will come to love these old names. I dare say many of these star names are 4,000 years old. Shepherds and sailors were the first astronomers. The sailors had to steer by the stars, and the shepherds could lie on the ground and enjoy them without having to twist their necks. They saw and named Alcor, thousands of years before telescopes were invented, and long before there were any books to help them. They saw the demon star, too, which I have never seen. It needs patience to see those things; sharp eyes are nothing to be proud of, because they are given to us. But patience is something to be eager about, because it costs us a lot of trouble to get it.

Let's try for it. We've had a test of sight. Now let's have a test of patience. It takes more patience than sharpness of sight to trace the outline of the Little Dipper. It has seven stars, too, and the Pole star is in the end of the handle. Do you see two rather bright stars about twenty-five degrees from the Pole? I hope so, for they are the only brightish stars anywhere near Polaris. Well, those two stars are in the outer rim of the Little Dipper. Now, I think you can trace it all; but to make sure you see the real thing, I will tell you the last secret.

The handle of the Big Dipper is bent _back_; the handle of the Little Dipper is bent _in_.

Now, if you have done all this faithfully, you have worked hard enough, and I will reward you with a story. Once upon a time there was a princess named Callisto, and the great G.o.d Jupiter fell in love with her. Naturally, Jupiter's wife, Juno, wasn't pleased, so she changed the princess into a bear. But before this happened, Callis...o...b..came the mother of a little boy named Arcas, who grew up to be a mighty hunter.

One day he saw a bear and he was going to kill it, not knowing that the bear was really his own mother. Luckily Jupiter interfered and saved their lives. He changed Arcas into a bear and put both bears into the sky. Callisto is the Big Bear, and Arcas is the Little Bear. But Juno was angry at that, and so she went to the wife of the Ocean and said, "Please, never let these bears come to your home." So the wife of the Ocean said, "I will never let them sink beneath the waves." And that is why the Big and the Little Dipper never set. They always whirl around the Pole star. And that is why you can always see them, though some nights you would have to sit up very late.

Is that a true story? No. But, I can tell you a true one that is even more wonderful. Once upon a time, before the bear story was invented and before people had tin dippers, they used to think of the Little Dipper as a little dog. And so they gave a funny name to the Pole star. They called it Cynosura, which means "the dog's tail." We sometimes say of a great man, "he was the cynosure of all eyes," meaning that everybody looked at him. But the original cynosure was and is the Pole star, because all the stars in the sky seem to revolve around it. The two Dippers chase round it once every twenty-four hours, as you can convince yourself some night when you stay up late. So that's all for to-night.

What! You want another true story? Well, just one more. Once upon a time the Big Dipper was a perfect cross. That was about 50,000 years ago.

Fifty thousand years from now the Big Dipper will look like a steamer chair. How do I know that? Because, the two stars at opposite ends of the Dipper are going in a direction different from the other five stars.

How do I know that? Why, I don't know it. I just believe it. There are lots of things I don't know, and I'm not afraid to say so. I hope you will learn how to say "I don't know." It's infinitely better than guessing; it saves trouble, and people like you better, because they see you are honest. I don't know how the stars in the Big Dipper are moving, but the men who look through telescopes and study mathematics say the end stars do move in a direction opposite to the others, and they say the Dipper _must_ have looked like a cross, and will look like a dipper long, long after we are dead. And I believe them.

CONSTELLATIONS YOU CAN ALWAYS SEE