"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.
[Illustration: 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?"