of
figures. They seemed like old friends. Before, a figure had only been
something in a "sum," but now he felt that each one had a long history
of its own. Little did he realize that the biggest step of his
mathematics was accomplished. Never again would he be able to look at a
page of figures with revulsion. They had come to life for him.

The next morning, Eric found the old puzzle-maker busy with a
chess-board.

"Aren't we going to do any work to-day, either?" he asked,
disappointedly.

"Soon as I finish," the old man answered. "Get pencil and paper. As I
move knight from square to square, you draw."

Shrugging his shoulders slightly, but not so noticeably that the
puzzle-maker could see, Eric obeyed. It seemed very silly to him. But as
the knight went from square to square in the peculiar move which belongs
to that piece in chess, the boy was amazed to find a wonderful and
fascinating geometrical design growing under his hand.

"Another way, too," said the old man thoughtfully, the instant the
figure was finished, not giving the boy a chance to make any comment.
And, without further preface he started again. This time an even
stranger but equally perfect design was formed.

"But that's great!" said Eric, "how do you know it's going to come out
like that! I wonder if I could do it?"

"Try him," the puzzle-maker answered, getting up from the board. For
half an hour Eric moved the knight about, but never got as perfect an
example as the old man.

"Are there only those two ways?" said the boy at last.

"Over thirty-one million ways of moving the knight so that he occupies
each square once," was the reply. "Every one makes a different design."

"I'll try some this evening," said the boy. "But it's funny, too. Why
does it always make a regular design?"

"You want to know? Very well." And the puzzle-maker quietly explained
some of the most famous mathematical problems of all time, working them
out with the chessmen and the board.

"You know what they call him, magic?" queried the old man.

"Magic! No!" exclaimed Eric pricking up his ears at the word. "Tell me
about it, Dan."

"Numbers all friends, live together, work together," the puzzle-maker
answered. "I show you." And, taking pencil and paper, he dotted down in
forms of squares and cubes rows and rows of figures. "Add him up," he
said, "up and down, cross-wise, any way. He all make same number."

"They do, sure enough," said Eric, after testing half