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?"