Part 4

Harry was so surprised that he had to try it for himself, and he looked forward with much delight to a visit from his cousin Nellie.

"Won't I have a lot to tell her?" he said to his sister: "all about the sun's melting her dollie, and how to make the sun burn a hole through a leaf. But the sun cannot be very far away, can it?" he asked.

DISTANCE OF THE SUN.

"Yes, it is very far away," replied Mary. "If a railroad could be made from the earth to the sun, and a train started going at the rate of a mile a minute, it would take days and weeks and years to get there.

"Let me see," said Mary, making a little note in her note-book. "There are sixty minutes in an hour, and twenty-four hours in a day, and three hundred and sixty-five days in a year. Why, Harry, do you know it would take that train nearly one hundred and seventy-five years to get there?"

"It must be very far away, then," said Harry, "more than a hundred miles."

"It is more than a million miles," said Mary. "It is nearly ninety-three millions of miles away. Now let us suppose you want to go to the sun. You would call at the railroad office and ask for a ticket to Sunland. The officer in charge would appear a little surprised, because that is quite a long trip. Then he would look up the cost of the journey in his book, and hand you a mileage book, saying: 'Sir, if you want to save money on this trip, you had better take a mileage book with you, costing two cents for every mile. Even then your fare will be nearly two million dollars.'"

"Then I would say: 'Dear sir, I cannot go, as I know my sister could not spare all that money. I think I would rather walk to the sun.' How long would it take me to walk there, supposing I could walk?" asked Harry thoughtfully.

"Dear, you would have to keep walking a very long time before you would ever get there. Supposing you walked four miles an hour, and ten hours a day, and kept this up for hundreds of years, you would be more than six thousand years on the way. When you reached the sun you would be footsore and weary, and as old as the hills."

Harry laughed heartily at the idea, and thought again of poor Nellie's doll and the melting wax running like tears down its cheeks.

"But suppose," he asked, his eyes bright with excitement, "someone fired a big cannon at the sun. Would the cannon-ball ever get there?"

Again Mary brought out her little note-book, and, with rather a look of surprise, she said: "Supposing the cannon-ball went as fast as it could go, it would take nine years to reach the sun, and the sound of the explosion would reach there in fourteen years. The cannon-ball would come along first, and five years afterward, if you were living on the sun, you would hear the sound made when the cannon was fired off.

"It takes time for me to walk from the garden to the house, so it takes time for sound to travel from the earth to the sky; and sound travels only one-fifth of a mile in a second. Do you remember the thunderstorm the other day, Harry, that frightened you so?"

"I shall never forget it," said Harry, trembling at the thought. "You said, 'Count slowly'; and I counted one, two, three, four, five, up to fifteen."

"Then I said: 'Don't be afraid, brother; the storm is three miles away.'"

"Yes, I remember," said Harry; "and I thought you were very clever, and wondered how you knew."

"It was not so wonderful, after all, was it?" said Mary, laughing.

"Now tell me, sister," said Harry. "Supposing I had a very long arm, and stretched it out toward the sun, and touched it with the tip of my little finger. What would happen?"

"You would never know that you had burned it, for the pain of burning would be one hundred and fifty years going along your little finger, and down your giant arm nearly ninety-three millions of miles long, before it at last reached your brain. Then it would let you know that one hundred and fifty years before you had burned your little finger."

Harry stretched out his little arm in the direction of the sun, and, looking at it critically, laughed at the idea of a giant arm millions of miles long.

"It is too short by several inches," said his sister, reading his thoughts, and joining in the laugh. "It would take hundreds and hundreds of little arms as long as yours, would it not? Now what else do you want to know about the sun?"

SIZE OF THE SUN.

"If you are not very tired, sister," said Harry coaxingly, "I should like to know how large it is. Is it as large as the earth?"

"Ever so much larger," replied Mary. "It is so large that if it were cut up into a million parts, each part would be larger than the earth. If we could weigh the sun in a pair of giant scales, it would take over three hundred thousand globes as heavy as the earth to make the scales even. If the sun were hollowed out, and the earth placed in the center, there would be room for the moon as well. Now the moon is thousands of miles from the earth, and yet the edge of the sun would be thousands of miles from the moon, as you will see in the picture. If a tunnel could be made through the center of the sun, and a train started going at the rate of a mile a minute, it would take six hundred days for the train to reach the other side of the tunnel. If this same train went around the edge of the sun it would take five years. A train going around the earth would take seventeen days to complete the journey."

"But suppose we went around the sun in a big steamer, like the one Uncle Robert came over in; how long would that take?" asked Harry curiously.

"Only fifteen years," said his sister, laughing. "If you had started when you were a little baby you would still have five more years to travel before you would get back again to the starting-point."

"Then the sun must be very large," said Harry thoughtfully. "Let us call it GIANT SUN. Has it always been as large as it is now?"

THE SUN IN THE DAYS OF ITS YOUTH.