"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?" [Illustration: 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. "Do you know," said Uncle Robert, "there are places all over the United States where such records are kept? They are published, and I am to have them sent to me every week."