Uncle Robert's Geography Part 12

"But what makes all this happen just now?"

"It's the sun," answered Donald from the floor, where he was playing with his great St. Bernard dog, Barri. "You know it rises earlier and sets later every day now than it did a while ago. It's hotter too."

"It goes higher at noon," said Frank. "In the middle of summer it is almost straight over our heads, and in the winter it seems ever so much farther to the south. I've often noticed that."

"So have I," said Donald. "And in the winter the shadows are longer than they are in summer. It must be because the sun isn't so high up."

"Aren't shadows funny?" said Susie. "One day when I was coming in to dinner, just for fun I tried to walk on my shadow, and I could step on my head."

"I've done that lots of times," said Donald. "But it's a strange thing.

Sometimes I can step clear over my head--I mean in the shadow--and then again I have to step on it."

"And when you jump," said Susie, "it spoils it. The shadow always jumps too."

"What kind of weather was it when you had to jump to it?" asked Uncle Robert.

"I don't remember," said Donald. "Would the weather make any difference?"

"I remember," said Susie, "because one time when I was jumping that way I fell down and was almost buried in the snow.

"Then it was winter, wasn't it?" asked Uncle Robert.

"It must have been," said Frank.

[Ill.u.s.tration: Shadow stick.]

"And since you told us that the shadows at noon tell why it is warmer in summer than in winter I've been watching them. They get shorter all the time." "How would you like to measure the shadows every day," said Uncle Robert, "and see if you can find out when they are shortest and when they are longest?"

"How can we?" asked Susie. "Shadows are so queer."

"Yes," said Uncle Robert, "shadows are queer, but, if we take one that doesn't jump as yours does, don't you think we can measure it?"

"Of course we can," said Frank. "We can use the house. That always stands still."

"The house might do," said Uncle Robert; "but wouldn't it be better to have a shadow stick?"

"Where can we get one?" asked Donald.

"What is it made of?" asked Frank.

"It is like this," said Uncle Robert, taking paper and pencil from his pocket. "There is one long piece of board, and one short one nailed to the end--so," drawing it on the paper.

"Oh, that's easy enough made," said Donald. "We can do it ourselves right here in the tool house."

"Let's make it to-morrow, Don," said Frank.

"It must be set up some place with the upright end turned toward the south, so that just at noon the shadow of the short piece may fall straight on the board. By drawing a line across the board at the top of the shadow and marking the date on it, we can tell how the length of the shadow changes."

"Uncle," asked Donald, "when it is winter here, is it summer in some other part of the world?"

"Yes," was the reply, "and now that our summer is coming, the people there are beginning to have winter."

"Then," said Frank, "when it gets cooler here in the fall it is growing warmer there, and that would make their spring come in September, wouldn't it? Do you see, Susie?"

[Ill.u.s.tration: Eskimo scene.]

"Yes," answered Susie, "but it seems all mixed up. I thought it was the same as it is here all over the world."

"Oh, I didn't," said Donald. "I've read about countries where it is summer all the time, and is so hot that the people don't do anything but lie under the trees and sleep. And there are other countries where it is winter all the time, and the people dress in furs and make their houses of snow and ice. I read all about it in a book once, but it didn't tell why it was so. I knew, of course, the sun had something to do with it."

"Why, you know, Don," said Frank, "we learned all that in our geography at school."

"Yes," said Donald, "but I never thought about that in the geography as meaning any real country."

"What did you think it meant?" asked Uncle Robert.

"Oh," said Donald, "just a lesson in the book."

"Well," said Frank, "I always thought it was some country, but I never knew where. I didn't think much about it after I said the lesson."

"I should think not," said Uncle Robert, not sorry that the teacher had gone away and the school had been closed.

"I wish when books tell things they'd tell why they're so," said Frank.

"Perhaps if we think about these things," said Uncle Robert, "we may be able to answer some of the 'whys' for ourselves."

"We can tell by the thermometer just how warm it is every day," said Susie, "but it won't tell us why."

"The shadow stick may help us there," said Uncle Robert.

"I am afraid I shall forget," said Donald.

"I have some little notebooks in my trunk," said Uncle Robert. "Suppose I give you each one and let you write down what the thermometer and the shadow stick say every day."

"What fun that'll be!" cried Susie. "When may we begin?"

"To-morrow morning, if you like," replied her uncle. "I will get the books for you now."

He went away to his room, and soon returned with the notebooks.

"I'll tell you, uncle," said Frank as he thanked Uncle Robert for his book, "how would it do for each of us to look at the thermometer at a different time of the day?"

"The very thing!" replied Uncle Robert, well pleased. "You are always up early, Frank, so suppose you look at six in the morning, Susie at twelve o'clock, and Donald at six in the evening. How will that do? Then we shall have the record for the whole day."

"I think it will be such fun!" said Susie. "I wonder if our books will be very different."

"What makes you think they will be different?" asked Uncle Robert.

"It's always hotter at noon than it is at night or in the morning," said Susie.