the boy's help.

His voice came with a sort of rasping scream that did not sound human,
and then broke into wild laughter, interrupted by broken words.

"Mad!" he cried. "I knew it--it had to come--my boy--help me to get away
from that thing--I'm raving mad--I see it moving--"

"But it really is moving, father! Wake up! Look at it! The wheel is
going round and round!"

Then Overholt was silent, sitting up on the floor and leaning against
his arm. Slowly he realised that he was in his senses, and that the
dream of long years had come true. Not a sound broke the stillness, so
perfect was the machinery, except a kind of very soft hum made by the
heavy fly-wheel revolving in the air.

"Are you sure, boy? Aren't we dreaming?" he asked in a low tone.

"It's going like clock-work, as sure as you're born," the lad answered.
"I think your falling down shook it up and started it. That was all it
wanted."

The inventor got up slowly, first upon his knees, at last to his feet,
never once taking his eyes from the beautiful engine. He went close to
it, and put out his hand, till he felt the air thrown off by the wheel,
and he gently touched the smooth, swift-turning rim with one finger,
incredulous still.

"There's no doubt about it," he said at last, yielding to the evidence
of touch and sight. "It works, and it works to perfection. If it
doesn't stop soon, it will go on for twenty-four hours!"

Almost as much overcome by joy as he had been by despair, he let himself
sink into his seat.

"Get me that tea-bottle," he said unsteadily. "Quick! I feel as if I
were going to faint again!"

The draught he swallowed steadied his nerves, and then he sat a long
time quite silent in his unutterable satisfaction, and Newton stood
beside him watching the moving levers, the rising and sinking valve
rods, and the steadily whirling wheel.

"She did it, my boy," Overholt said at last, very softly. "Your mother
did it! Without her help the Motor would have been broken up for old
metal three weeks ago."

"It's something like a Christmas present," Newton answered. "But then I
always said she wouldn't let you give it up. Do you know, father, when
you fell just now, I thought you were dead, you looked just awful! And
it was quite a long time before I saw that the Motor was moving. And
then, when I did see it, and thought you were dead--well, I can't tell
you--"

"Poor little chap! But it's all right now, my boy, and I haven't spoilt
yo