Rollo's Experiments Part 8

"You know that boards are made from the stems of tall trees."

"Yes," said Rollo.

"Well, now when trees are growing, there are little channels running up and down from the roots to the branches."

"What are they for?" said Rollo.

"They are for the sap. The sap flows up and down in them. But then there are no channels across from one side of the tree to the other, because there is no sap to go across. The sap all has to go up from the roots to the branches; and so the channels must all be up and down the tree.

"Now," continued Jonas, "when they cut down the tree, the trunk will split easily, up and down, the way the channels and fibres all go; but it won't split easily across. And just so, when they saw it up into boards, the boards will all split lengthwise, from end to end, for this is the way the channels and fibres all lie; but it won't split across, for that would be across all the fibres, and the wood is made very strong in that direction, and it is well it is so."

"Why?" said Rollo.

"Because, if trees would split across, as easily as they do up and down, the first good wind would blow down all the forests in the world."

"O, Jonas!" exclaimed Rollo, "all the forests in the world?"

"Yes," replied Jonas, "if the wind blew all over the world."

HOROLOGY.

One day, at eleven o'clock, Rollo, after having put away his books carefully into his desk, went out to play. It was a calm and pleasant autumnal day. Brown and yellow leaves were falling from the trees, and lying about the yard. Rollo found Nathan sitting upon the steps of the door which looked toward the garden yard. He felt satisfied and happy, for he had studied his lessons diligently, and, when he saw Nathan, he concluded to have a little play with him.

"Now, Nathan," said Rollo, "I will lie down upon the steps, and make believe I am a bear gone to sleep, and you come and poke me with your stick, and then I will growl at you."

"Well," said Nathan, "I will."

So Rollo laid down upon the steps, putting his arms upon the threshold of the door for a pillow, and his head upon his arms, and pretended to be asleep; but he did not look much as if he was asleep, after all, for he could not look quite sober. He tried to look sober; but there was a lurking smile upon his face, which made his countenance look quite different from that of a bear. Nathan came creeping along softly, and when he got near enough, he began to poke him with the end of his little whip-handle; then Rollo would start up and begin to growl, when Nathan would scamper away, shouting with laughter, Rollo after him, upon all-fours.

This play lasted several minutes, until at length Nathan spoiled it by punching Rollo too hard with his whip-handle. A great many plays are spoiled by roughness on the part of some who are engaged. Rollo, being hurt a little, got out of patience. He ought to have asked Nathan, pleasantly, not to punch him so hard. Instead of that, however, he declared that he would not play any more, and got up and went away.

Nathan followed him, lashing the ground and the leaves with his whip.

They both went into a corner of the yard, where Rollo used to have his sand-garden. This sand-garden was made of clean sand, which Rollo and his cousin James once wheeled up from the brook; and then, after they had smoothed it out, and raked it over, they used to get plants and flowers, without any roots, and stick down, and then call it their garden. They used to water the plants, and so they could keep them green and bright for several days, which was long enough for them; for, after that, they generally preferred putting down fresh ones. But, now, the sand-garden had been for a long time neglected. The remains of some of the old plants were there, withered and dried, and the leaves of autumn were scattered over its surface.

Rollo began to rake off the leaves with his fingers, and then sat down, and went to digging a hole in the sand. It was very dry upon the top, but on digging down a little way, he found it damp, and so it would hold together pretty well, and he could pat it into any shape. A load of clean sand makes a very good place for children to play in, in a corner of a yard.

Rollo sat down on one side of the sand-garden, and Nathan on the other, and both busied themselves in digging and building little houses. They both became very much interested, and sat some time very still, until, at length, Rollo looked around to see what Nathan might be doing.

"What are you doing, Thanny?" said he.

"O, I'm making the sand run down through."

Rollo observed that Nathan had an old tin dipper, which he was holding up in one hand, and putting some dry sand into it with the other. There was a very small hole in the bottom of the dipper, for it was an old one which had been worn out and thrown away; and the sand ran out of this little hole in a fine stream, and it was this which interested Nathan so much.

"O, Nathan," said Rollo, "let me have the dipper."

"No," said Nathan, "I want it myself."

Rollo would not take it away from Nathan, though he wanted it very much indeed.

"Yes, Nathan," said he, "let me have the dipper, and I will make you an hour-gla.s.s out of it."

But Nathan said, "No, no," and moved away a little farther.

Rollo then remembered that such a little boy was generally not interested in any one thing very long, and that, if he should let Nathan alone, he would soon put the dipper down, and then he could have it without any difficulty. So he went on making houses in the sand, and in a few minutes Nathan put the dipper down. Then, soon after, Rollo took it up and put some dry sand into it, and he found that the sand would run very smoothly, in a fine stream, through a small hole there was in the bottom of it.

He determined to make an hour-gla.s.s of it. He had seen an hour-gla.s.s at his uncle George's. It was made of gla.s.s, big at the bottom and at the top, and narrow in the middle between the two. Through the narrow part in the middle, there was a very small hole, to let the sand run down through; and there was just sand enough put in to run through in an hour. So that, if a person should set the sand to running, he would know when an hour had expired, by observing when the sand had all run through.

Rollo thought that he could make an hour-gla.s.s; and he thought it would be a great convenience to him to have an hour-gla.s.s in the yard; because it often happened, when he came out to play, that his mother would tell him that he might stay out an hour; and then he had to go in very often to look at the clock, in order to know exactly when the hour had expired.

There were, however, so many little sticks and old leaves in the sand, that it kept getting continually clogged up, and at last Rollo began to get discouraged. He tried to pick out the little sticks; but he found he could not do that, and at last it occurred to him that probably Dorothy had some sand in the house that was cleaner.

He accordingly went in and asked her. She told him that he must wash his own sand, and that would make it clean.

"But haven't you got some that is clean already?" said he.

"Yes," said Dorothy; "but you will like your hour-gla.s.s better if you make it all yourself."

So Dorothy told him how to wash sand, for Rollo said that he did not know. She said he must put a little in a basin, and then pump water into it. "When the basin is nearly full of water, you must stir it round, and then pour off the water, and pump in more;--do this until the water comes off clear."

So Rollo took the basin which Dorothy gave him, and went out to his sand-garden, and put in a little sand. Then he went to the pump, and pumped water into it. Then he stirred it about with his hand. The water immediately became very turbid, and a great many little sticks and leaves came floating up to the surface. Rollo was surprised to find how rapidly the water separated the light things which would float upon the top, from the heavy sand which would sink to the bottom. He kept pouring off the water, and pumping in more, until at length no more sticks and leaves came off, and the water appeared pretty clear. Then he carried the sand away, and spread it out upon a clean board in the sun to dry.

While he was thus at work preparing the sand for his hour-gla.s.s, Jonas happened to come by, and asked Rollo what he was doing. Rollo told him that he was making an hour-gla.s.s. Jonas looked on for a few minutes, and then he told Rollo that he thought that was a pretty good plan. "And _I_ am going to have a time-keeper, too," said he.

"Are you?" said Rollo. "What?"

"I am going to make a dial," said he.

"A dial!" said Rollo; "what, a real dial?"

Rollo had an idea that a dial was exceedingly complicated and difficult to make, or to understand; and, in fact, it is difficult to make one that shall be exact in its indications. He did not think it possible that Jonas could make one.

"Yes," said Jonas, "a real dial; and I have got a noon mark already."

"A noon mark!" said Rollo; "what is a noon mark?"

"It is a mark to show when it is exactly twelve o'clock."

"Let me go and see it," said Rollo, "while my sand is drying."

Rollo followed Jonas off into the barn, and when there, Jonas pointed to a small line which he had cut with his penknife upon the barn floor. It began at the foot of one of the posts, by the side of the door, and extended back into the barn exactly straight.

"Is that the noon mark?" said Rollo. He was surprised to see that a noon mark was nothing but a cut with a penknife upon a barn floor.