r he was a keen baseball fan. As the sketch grew the old man
talked, describing a queer entanglement of play.

"Now!" said the old man, "what shall he do?"

The boy, judging from his knowledge of the game, made a suggestion,
which the other negatived. As soon as the boy made a guess, the other
showed him to be wrong. Eric, really interested in the baseball problem,
cudgelled his brains, but could find no way out.

"I show you!" the old man repeated.

Using a very simple rule of algebra, which the boy knew quite well, but
giving an application he never would have thought of, Dan brought the
solution in a second. Hardly believing that mere mathematics could be of
any service in a baseball game, Eric tested the result. It was exactly
as the old man had said.

"Gee," he said, "that's great!"

The puzzle-maker smiled, and showed him how mass-play in football was a
matter of science, not strength, and how lacrosse was a question of
trajectory.

"Not only in games," he said. "'Rithmetic, geometry--in everything. You
know Muldoon."

"Sure I know Muldoon," the boy said.

"Have you seen him shoot?"

"With the Lyle gun, you mean? Isn't he a dandy at it?"

"That is what I would say," the old man continued. "How does he fire
him?"

"Why, he just fires it! No," he corrected himself, "he doesn't either. I
see what you're driving at. That's right, I did see him doing some
figuring the other day."

"I teach Muldoon," said the old man. "I show him how to tell how much
wind, how to tell how far away a ship, how to tell when a line is heavy
or light. He figure everything, then fire. Bang! And the line to bring
the drowning men home falls right over the ship. It is?"

"It is, all right," the boy agreed. "Muldoon gets there every time. I
always thought he just aimed the gun, sort of naturally."

"It is all mathematics," said the old man. "You have guns in the Coast
Guard?"

"Rapid-fire six-pounders," the boy answered. "At least I know that's
what the _Itasca's_ got. She's the practice-ship at New London, you
know."

"Do you have to learn gunnery?"

"Rather," said the lad. "Every breed of gunnery that there is. You know
a Coast Guard cutter becomes a part of the navy in time of war, so an
officer has got to know just as much about big guns as an officer in the
navy. He might have to take his rank on a big battleship if the United
States was at war. You bet I'll have to learn gunnery. That ought to be
heaps of fun."