"O," said Rollo, "I can easily make a hut of hemlock branches, and we can go into that for shelter."
"But, Rollo," said Nathan, "how do you know but that it will snow all day? We can't stay in the woods all day."
"No," said Rollo; "when it snows in great flakes, it is not going to snow long. Jonas told me so."
So the children went into the woods, and Rollo began to make his hut; but he was soon interrupted, and the attention of all the children was called off by a little bird, which they saw there, hopping about, and appearing benumbed with cold. After some effort, Rollo succeeded in catching her in his cap.
"We'll carry her home," said Nathan; "we'll carry her home, and show her to mother."
"Yes," said Rollo, "I'll carry her in my cap."
"No," said Lucy, "you must have your cap on your head, or you will take cold. Let me carry her in my hands."
"No," said Rollo, "you will have to lead Nathan. I'll tell you what we will do. We will put her into the basket, for a cage."
Lucy, on the whole, liked this plan, and they accordingly put the bird in the basket, and Rollo contrived to make a cover of boughs, to keep her from getting away.
By the time that this was all arranged, the children found, to their great satisfaction, that it had ceased snowing; and they immediately set out for home. Rollo drew the sled, with the basket and bird upon it, secured as before with the cord; and Lucy led Nathan. They now had no difficulty in finding their way, and soon reached home in safety.
They kept the bird until the next day, and then, as it was mild and pleasant, they let her fly away.
QUESTIONS
By what process had the snow become hardened at this time? Did Rollo's father expect that it would continue hard till noon? Why not? Did it continue hard? What prevented its melting? How did Rollo get sticks for his fire? What name did he give to the hill which they ascended? What occasioned the difficulty in the way of Rollo's finding his way home? What conversation took place when he found the track? Was this track in the new snow, or in the old snow? How had it become partly obliterated? How did they carry the bird home?
CHAPTER II.
FLYING
Nathan became very much interested in the bird, and that evening, as his father was sitting by the fire, with a book in his hand, which he had been reading, Nathan came up to him, and said,—
"Father, are you busy now,—thinking, or anything?"
"No," said his father.
"Because," said Nathan, "if you are not, I want to read you something out of my little book."
So Nathan's father took him up into his lap, and Nathan opened his little book, and began to read as follows:—
"'With fins for the water, and wings for the air,
And feet for the ground, I could go everywhere.'
"Isn't that funny?" said Nathan.
"Rather funny," said his father.
"I wish I had wings," said Nathan.
"Why?" said his father.
"Why, then I could fly."
"That is not certain," said his father. "There are two difficulties which prevent boys from flying. One is, they have no wings; and the other is, they have not strength to use them."
"O father," said Nathan, "I could use them; I am pretty strong. I can wheel Rollo's wheelbarrow."
His father smiled. "Very possibly," said he; "but I do not think that you would be strong enough to use wings, even if you had them."
"Why, at any rate, I am stronger than a bird," said Nathan.
"Yes," said his father, "you have more actual strength than a bird, but not more in proportion to your size. You are absolutely stronger, but not relatively."
"What do you mean by that?" said Nathan.
"Why, you have actually more strength than a bird,—a robin, for instance; you could hold him so that he could not get away; and you could lift more than he could too. But then you are a great deal larger, and you are not as much stronger than he is, as you are larger. If you are a hundred times as heavy as he, you are not a hundred times as strong. That's what I mean by saying that you are absolutely stronger, but not relatively. That is, you are not as many times stronger, as you are larger and heavier. You are absolutely stronger, but not relatively; that is, in proportion to your size and weight.
"Now I can prove to you," continued his father, "that you would not be strong enough to fly with wings, even if you had them. Suppose there was a pole fastened across the room, and another pole just above it; could you pull yourself up, from one pole to the other, by your hands alone, without touching your feet?—Or a ladder," continued his father,—"it will be better to suppose a ladder. Now, if there was a ladder leaning up against a building, could you climb up on the under side by your hands, drawing yourself up, hand over hand, without touching your feet?"
Here Rollo, who was reading in a little chair at the back part of the room, when his father first commenced the conversation with Nathan, but who had been listening for a few minutes past to what his father had been saying, jumped up, and came across the room to his father, and said,—
"Yes, sir, yes, sir; I can. I have done it often in the barn."
"How high up could you go?" said his father.
"O, almost up to the loft," said Rollo. "Only, you see, father, the rounds are too far up. I can't reach up very well. If they were nearer together, I could climb up so, very well."
"Well," said his father, "a bird, when flying, has to climb up in much the same way. He has to pull himself up by the air, with his wings, just as you do with your hands and arms, by the rounds of the ladder; only the air is not fixed, like the ladder, but constantly gives way under his wing; and so, to make the case the same, you must suppose that the ladder is not firm, but is floating in the air, and sinks down with your weight, so that you have to climb up faster than you pull the ladder down. Do you think you would have strength enough in your arms to do that?"
Rollo and Nathan looked very much interested in what their father was saying, but they both admitted that they could not climb up such ladders as those.
"The air," added their father, "gives way continually under the bird's wing; and yet they have to pull themselves up by it. And this is very hard. They must either have very large wings, and prodigious strength to use them, so as to pull upon the air with very hard and heavy strokes, or else, if they have small wings, they must have strength to strike very quick and often with them.
"The wings of sparrows move so quick, that you cannot count the strokes; and those of humming-birds, which are smaller still, so fast that you cannot see them. They make a hum."
"I could make my wings go so fast," said Nathan; and he began to imitate the flapping of the wings of a bird, with his arms, as rapidly and forcibly as he could.
"So can I," said Rollo; and he made the same motions. "That is as fast as crows' wings move, when they are flying."
"Yes," said his father, "crows move their wings as fast as that, whereas you only move hands and arms. If you had great wings, as long, in proportion, as the crows, you could not move them so fast."
"How large would they be?" said Rollo.
"O, I don't know,—perhaps as big as the top of the dining-table."
"O father," said Rollo, "I don't think they would be as big as that. The crow's wings are not longer than his body, and so mine would not be longer than my body."
"Perhaps you never saw a crow's body," said his father. "His feathers and his tail, which are very light, swell out his body, and make