Mars so" lar (ler) Ve" nus plan" ets Mer" cu ry di am" e ter com" pa.s.s es sat" el lite tel" e scope grad" u al ly in" ter est ing cir c.u.m" fer ence
THE SUN"S FAMILY
"Please tell me a story, Frank" said Philip, as the two boys sat in the shade of a large tree.
"I have heard and read many wonderful stories. I will try to recall one," said Frank.
"Let me see. Well--perhaps--I think that the most wonderful story I have ever read is that of the solar system, or the sun"s family."
"Solar system!" repeated Philip. "That certainly sounds hard enough to puzzle even a fairy. Please tell me all about it."
"That I should find much too hard" answered Frank. "But I"ll try to tell you what little I know. You see the sun there, don"t you--the great shining sun? Do you think the sun moves?"
"Of course it moves," said Philip. "I always see it in the morning when I am in the garden. It rises first above the bushes, then over the trees and houses; by evening it has traveled across the sky, when it sinks below the houses and trees, out of sight on the other side of the town."
"Now that is quite a mistake," said Frank, "You think that the sun is traveling all that way along the sky, whereas it is really we--we on this big ball of earth--who are moving. We are whirling around on the outer surface, rushing on at the rate--let me think--at the rate of more than one thousand miles a minute!"
"Frank, what do you mean?" cried Philip.
"I mean that the earth is moving many times faster than a ball moves when shot from the mouth of a cannon!"
"Do you expect me to believe that, Frank! I can hardly believe that this big, solid earth moves at all; but to think of it with all the cities, towns, and people whirling round and round faster than a ball from the mouth of a cannon, while we never feel that it stirs one inch,--this is much harder to believe than all that the fairies have ever told us."
"Yes, but it is quite true for all that," replied Frank.
"I have learned much about the motions of the planets, and viewed the stars one night through a telescope. As I looked through this instrument, the stars appeared to me much larger than ever before. The earth is a planet, and there are besides our earth seven large planets and many small ones, which also whirl around the sun. Some of these planets are larger than our world. Some of them also move much faster.
"The sun is in the middle with the planets moving around him. The one nearest to the sun is Mercury."
"It must be hot there!" cried Philip.
"I dare say that if we were in Mercury we should be scorched to ashes; but if creatures live on that planet, G.o.d has given them a different nature from ours, so that they may enjoy what would be dreadful to us.
"The next planet to Mercury is Venus. Venus is sometimes seen shining so bright after sunset; then she is called the evening star. Some of the time, a little before sunrise, she may be seen in the east; she is then called the morning star.
"Venus can never be an evening star and a morning star at the same time of the year. If you are watching her this evening before or after sundown, there is no use getting up early to-morrow to look for her again. For several weeks Venus remains an evening star, then gradually disappears. Two months later you may see her in the east--a bright morning star.
"Our earth is the third planet, and Mars is the fourth from the sun. Now let us make a drawing of what we have been talking about.
"First open the compa.s.ses one inch; describe a circle, and make a dot on its circ.u.mference, naming it Mercury. Write on this circle eighty-eight days; this shows the time it takes Mercury to travel around the sun.
Make another circle three and one-half inches in diameter and make a dot on it. This represents Venus. It takes Venus two hundred twenty-five days to journey around the sun.
"The next circle we have to draw is a very interesting one to us. The compa.s.ses must be opened two and one-half inches. The path made represents the journey we take in three hundred sixty-five days.
"One more circle must be drawn to complete our little plan. This circle must be eight inches in diameter. You see Mars is much farther from the sun than our earth is. It takes him six hundred eighty-seven days to make the trip around the sun. The other planets are too far away to be put in this plan."
"O, Frank, you have missed the biggest of all--the moon!" said Philip.
"O, no, no!" exclaimed Frank. "The moon is quite a little ball. It is less than seven thousand miles around her, while our earth is twenty-five thousand miles around."
"Is that a little ball, Frank?"
"Yes, compared with the sun and the planets. The moon is what is called a satellite--that is, a servant or an attendant. She is a satellite of our earth. She keeps circling round and round our earth, while we go circling round and round the sun.
"How fast the moon must travel! If I were to go rushing round a field, and a bird should keep flying around my head, you see that the movements of the bird would be much quicker than mine."
"I can"t understand it, Frank," said Philip. "The moon always looks so quiet in the sky. If she is darting about like lightning, why is it that she scarcely seems to move more than an inch in ten minutes?"
"I suppose," said Frank, after a thoughtful silence, "that what to us seems an inch in the sky is really many miles. You know how very fast the steam cars seem to go when one is quite near them, yet I have seen a train of cars far off which seemed to go so slowly that I could fancy it was painted on the sky."
"Yes, that must be the reason; but how do people find out these curious things about the sun and the stars--to know how large they are and how fast they go?" asked Philip.
"That is something we shall understand when we are older," said Frank.
"We must gain a little knowledge every day."
"Is the earth the only planet that has a moon?" asked Philip.
"Mercury and Venus have no moons. Mars has two, and Jupiter has four, but we can see them only when we look through a telescope." replied Frank.
"Are all the twinkling stars which one sees on a fine clear night, planets?" inquired Philip.
"Those that twinkle are not planets; they are fixed stars," said Frank.
"A planet does not twinkle. It has no light of its own. It shines just as the moon shines, because the sun gives it light."
"But our earth does not shine!" said Philip.
"Indeed it does," explained Frank. "Our earth appears to Venus and Mars as a shining planet."
"There must be many more fixed stars than planets, then, for almost every star that I can see twinkles and sparkles like a diamond. Do these fixed stars all go around the sun?" asked Philip.
"O, Philip! haven"t you noticed that they are called fixed stars to show that they do not move like planets? The word _planet_ means to _wander._ These fixed stars are suns themselves, which may have planets of their own. They are so very far away that we cannot know much about them, except that they shine of themselves just as our sun does.
"We know that our sun gives light and heat to the planets and satellites with which he is surrounded. We know that without his warm rays there would not be any flowers or birds or any living thing on the earth. So we can easily imagine that all other suns are shining in the same way for the worlds that surround them."
Make a drawing of the sun and the three planets nearest it, as directed in the lesson.
Fill each blank s.p.a.ce in the following sentences with the correct form of the action-word _draw_:
My boys like to --.
Yesterday they -- the picture of an old mill.