It was a busy time on the farm. Only when the day's work was over and
they were gathered in the sitting-room was there time for the long talks
with Uncle Robert that they all enjoyed so much.

"It's wonderful," said Mr. Leonard one evening, looking up from his
paper, "how fast the corn is growing. Even the late planting is coming
on."

"That's because the weather is so warm," said Donald.

"I wonder what makes it warm?" said Uncle Robert.

"Why, Uncle Robert," exclaimed Susie, "it's spring! That's what makes it
warm."

"But what makes it spring, little girl?" asked Uncle Robert.

"Why, it is always spring in May," said Susie.

"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?"