them food. "Eat, little sons," she would say. "You must
not die."

The brothers worked all day. They were real students.
One brother was Halfoff. He was taller than the other
and stronger. The other brother was Kwitoff. He was not
so tall as Halfoff and not so strong.

One day Serge went to the room of the brothers. The
brothers were at work. Halfoff sat at a table. There was
a book in front of him.

"What is it?" asked Serge.

"It is solid geometry," said Halfoff, and there was a
gleam in his eyes.

"Why do you study it?" said Serge.

"To free Russia," said Halfoff.

"And what book have you?" said Serge to Kwitoff.

"Hamblin Smith's _Elementary Trigonometry_," said Kwitoff,
and he quivered like a leaf.

"What does it teach?" asked Serge.

"Freedom!" said Kwitoff.