The boys then went back to the front door of the barn, and, to their surprise and alarm, found that fastened too.
"What shall we do?" said Rollo; "Jonas has fastened us in." As Rollo said this, his face a.s.sumed an expression of great solicitude, and Nathan began to cry.
"Don"t cry, Nathan," said he; "we can find some way to get out. But I don"t see, I confess, what made Jonas lock us in."
The truth was, that Jonas did not know that the boys were in the barn when he fastened it up. As they did not come back after they had gone to answer the bell, he supposed that they had gone into the house; and when he was ready to come in himself, he shut and fastened the back doors of the barn, as he usually did when he left the shop. He then came around to the front barn door, and although that was on the sheltered side, so that the wind did not blow in, he thought it possible that the wind might change, and so drive the snow in upon the barn floor; and therefore, to make all safe, he thought that he would shut them, too. He accordingly shut the great doors, and put the fid into the staple. The fid is a wooden pin, to be pa.s.sed through the staple when the doors are shut, to fasten them. The doors cannot be opened again until the fid is taken out.
Rollo went all around the barn, trying to find some place where he could get out; but he could not find any place at all.
"Let us go up stairs," said he, at length, to Nathan.
"O, it will not do any good to go up stairs," said Nathan. "It would kill us to jump out the window."
"I know we can"t jump out the window," said Rollo, "but perhaps we can find out some way to get down. O, there is a ladder; I remember now, Nathan, there is a ladder. We can get down from the window by the ladder."
"I shall be afraid to go down the ladder," said Nathan.
"O no," said Rollo, "I will go first, and see if it is safe."
By this time they had reached the barn chamber. There was a window in it, with gla.s.s, over the great barn door; but Rollo could not get it open. He told Nathan that, if he could only get it open, and could find a long pole, he could reach it down, and knock the fid out, and so open the great doors. But, with all his efforts, he could not raise the window.
There was another window, which had no gla.s.s, but was closed by a wooden shutter, which opened upon hinges like a door. Rollo said he meant to open this window. Now, it happened that this window was upon that side of the barn which was exposed to the wind and storm; and, the moment that Rollo had pushed open the shutter a little way, the wind forced it instantly from his hand, and slammed it back against the side of the barn, with great violence. It almost pulled Rollo himself out of the window.
Nathan looked frightened. Rollo himself looked somewhat astonished at such an unexpected effect; but presently said,--
"Well, Nathan, I rather think that, if you had had hold of that shutter, you would have thought that air was a real thing."
"O, that was the _wind_, Rollo; that was the _wind_," said Nathan.
Rollo did not answer, but went to the ladder, which was standing up against the hay-loft. It was a pretty long, but yet a very light ladder; and Rollo and Nathan succeeded, after some difficulty, in getting it down, and in running the end out of the window. When the lower end reached the ground, the upper end was two or three feet above the bottom of the window; so that Rollo could easily get upon it to descend. The wind and storm, which raged with great violence, were somewhat terrifying; but he knew that the ladder was secure, the upper part being confined in the window; and so he resolutely descended. When he had fairly reached the ground, he looked up, with an expression of great satisfaction upon his countenance, and said,--
"There! now, Nathan, for your turn."
But Nathan was afraid to venture; and Rollo himself was half afraid to have him make the attempt. While they were standing in this perplexity, Rollo heard a voice behind him, calling out,--
"Rollo."
Rollo turned, and saw Dorothy standing by the door.
"What are you doing, Rollo?" said Dorothy.
"I am trying to get Nathan out of the barn," said Rollo.
"How came he in the barn?" said Dorothy.
"Why, Jonas locked us in, and I had to come down the ladder; but Nathan is afraid, and I can"t get him out."
"Why don"t you go to the door, and let him right out?"
"O," said Rollo, laughing, "I never thought of that. Go down, Nathan,"
he continued, "to the door, and I will go round and knock out the fid."
So Nathan went down, and Rollo, meeting him there, knocked out the fid, and released him from his imprisonment.
QUESTIONS.
What was the first experiment with the bellows, described in this chapter? Why could not Nathan press the two sides of the bellows together, while the nose was stopped? What was the second experiment? What was the effect produced by turning the bellows bottom upwards, as in the third experiment? What was the fourth experiment? What was the use of the smoke of the paper?
How were the experiments interrupted? What evidence did Rollo and Nathan have that the air was a real substance, when in the barn chamber?
CHAPTER V.
PRESSURE.
One evening, just after tea, Rollo came to his father, who was sitting by the side of the fire, and said,--
"Father, I wish we could see the air, as we can the water, and then perhaps we could try experiments with it."
"O, we can try experiments with the air as it is," said his father.
"Can we?" said Rollo; "I don"t see how."
"We cannot see the air, it is true; but then we can see its effects, and so we can experiment upon it."
"Well, at any rate," said Rollo, "we can"t build a dam, and make it spout through a hole, like water."
"No," said his father, "not exactly. In your dam, for instance, when it was full, you had water on one side of the board, and no water on the other; and then, by opening a hole in the board, the water spouted through; but we cannot very well get air on one side of a part.i.tion, and no air on the other; if we could, it would spout through very much as the water did."
"Why can"t we do that, sir?" said Rollo.
"Because," replied his father, "we are all surrounded and enveloped with air. It spreads in every direction all around us, and rises many miles above us. Whereas, in respect to water, you had one little stream before you, which you could manage just as you pleased. If you were down at the bottom of the sea, then the water would be all around you and above you; and there, even if you could live there, you could not have a dam."
"No, sir," said Rollo, "the water would be everywhere."
"Yes," replied his father, "and the air is everywhere. If, however, we could get it away from any place, as, for instance, from this room, then bore a hole through the wall, the weight of the air outside would crowd a portion of it through the hole, exactly as the weight of the water above the board in your dam crowded a part through the hole in the board."
"I wish we could try it," said Rollo.
"We _can_ try it, in substance," said his father, "in this room; or--no, the china closet will be better."
There was a china closet, which had two doors in it. One door opened into the parlor, where Rollo and his father were sitting. The other door opened into the back part of the entry. Rollo"s father explained how he was going to perform the experiment, thus:--
"If we could, by any means, get all the air out of the closet for a moment, then the pressure of the air outside would force a jet of it in through the key-holes of the doors, and the crevices."