"THERE!" said little Margaret Darnley, in despair, as she stood, broom in hand, at the north door. The dust, and sits of paper, and string, and clippings of cloth, which she had been collecting from all over the room with her broom, kept drifting back persistently when she tried to sweep them out at the door; and worse than all were the feathers from the pillow of Myra's doll, which were scattered in every direction. Myra did sew dreadfully, and a pillow was the last thing she ever ought to have made. And everybody knows what hard things to sweep up feathers are. Margaret leaned against the wall, tired out.

"Why don't you try the other door, Maggie?" asked her brother Jack, who sat by the window.

"That is just the queer part of it," said Margaret. "I tried the other door first, and it is just as bad there. The wind can't blow in exactly opposite directions at once, can it?"

"May be it shifted while you were sweeping the dirt across the room," said Jack.

"Well, that would be funny," said Margaret; "but I'll try it again. It will be a sort of experiment, I guess."

"A sort of what?" asked Jack.

"A experiment," said Margaret. "I listened to your philosophy teacher the other day, and Mr. Baird said that everything in science had to be—something by experiments."

"Verified by experiments," said Jack, laughing.

"Yes, that's so, and now we'll see if there's any philosophy about this dirt."

So Margaret swept the dirt carefully across the room again, while Jack looked on.

"There!" exclaimed Margaret, "look at that." Jack did look, and had to confess that it was too much for his philosophy. "Stop," said he,

"I'll see which way the wind is really blowing." Margaret shut the door, and sat down to wait. The poor little arms were quite tired by this time; for Margaret was only ten years old, and was but just learning to sweep.

"It's the stillest day we've had this season," cried Jack, bursting in. "The weather-cock turns tail to the south, so whatever wind there is comes from the north. Let's try the south door again."

To the surprise of both Jack and Margaret, the dirt, which had been so perverse and contrary, went out this time without making much trouble.

"Tha 's it—the wind shifted, don't you see, Maggie?" said Jack, with a wise look. "That's the way with science. Science believes nothing till it has thoroughly proved it. That's what experiments are for, and that's "the beauty of science."

"Open the draft, Jack, and put in some more wood.  What makes this room so cold?" called their father from a small adjoining room, which he used as a study. "What's that you were saying about science?" he added, with a quizzical look on his face.

Jack, with a very grave and scientific look, explained their experiment in natural philosophy.

"Ah!" said his father, "the wind shifted, did it.  How many times?"

" Why, four times, father," said Margaret.

"Just as quick as lightning—almost," she added, seeing her father raise his eyebrows. "I swept the dust from, one door to the other just as quick as I could; but by the time I got there, the wind got there too, and blew the dirt back every time."

"Suppose we try the experiment again," said Mr. Darnley.

"Oh, I've swept all the dirt out now," said Margaret, "for after we had tried and, tried, it finally went out quietly."

"Well, here -are a few feathers which gave you the slip, little Pearlie," said her father. "We can try the experiment with them. Put in some more wood, and make the room pretty hot."

"What for, father?" asked Jack, who was not very fond of carrying wood.

"It is necessary to our experiment," said his father. Jack put in the wood. This was mysterious and interesting.

"Now, Maggie," said her father, when the room was uncomfortably warm, "get your broom and sweep out these feathers."

"Which door, father?" asked Margaret.

"It makes no difference," said her father,

"either door will do."

"Better let me look at the weather-vane again," said Jack.

"It is not necessary," said his father, smiling. Margaret tried again, but the feathers all blew back, some entirely across the room.

"There they are, Maggie, close to the south door," said Mr. Darnley. "I'll shut this door, and you may sweep them out at that one." But Margaret had no better success than before.

"Isn't it curious!" said Jack. "There must be witches standing in the door, blowing the feathers back."

"That is what ignorant and superstitious people would have said years ago, Jack," said his father, "but science shall teach us better than that."

"Now," continued Mr. Darnley, "let us make two piles of the feathers—one near the south and the other near the north door. Jack, get another broom for this pile. Now, both sweep in opposite directions at the same time. That will show us whether it is caused by the shifting of the wind." Jack and Maggie tried faithfully, but the feathers went every way but out of the doors, some of them even rising toward the ceiling.

"It's the cold day," said Jack; "they don't like to go out."

"Father, what is the reason, please?" asked Margaret, earnestly.

"Hot air always rises," replied Mr. Darnley.

"Why?" asked Margaret.

"Because," answered her father, "hot air is lighter than cold.  When it rises, of course cold air rushes in to fill its place. When you open the door, currents of cold air rush in at the bottom, while the hot air is escaping at the top. Open the door, Jack, and try to drive out a feather above your head, while Maggie tries one at the floor."

The children did so, and found that, while the feather at the bottom blew in, the one at the top floated out.

"But, father," said Maggie, "we did sweep the dirt out at last. Why was that?"

"Because you had let the room grow cold while you were trying your experiments," said her father, "and as the temperature became more like that outside, the currents were less strong. That is the way your 'wind shifted.' " Jack looked foolish.

"Science is a fine thing, my son," continued his father, "and great beauty and interest, as well as importance, attach to its discoveries.  But the life and soul of science lie in its exactness and thoroughness.  A scientific experiment, to be worth anything, must be thorough. You tried an experiment half-way, and then jumped to a conclusion."

"Mother," said Margaret, "how do you sweep the dirt out?"

"I take it up on the dust-pan, Maggie, dear," said her mother, smiling.  Jack and Maggie had both learned something that morning.




Jane Eggleston Zimmerman.