"I know of a country where it is spring in September," replied Uncle
Robert.
"How can it be?" asked Susie. "I thought springtime always came in May."
"What makes us know that it is spring?" asked Uncle Robert.
"Oh, it gets warmer all the time. The birds come, things begin to grow, and the flowers bloom."
"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."