, father? It didn't look
just then as if we were going to have a roaring old Christmas this year,
did it?"

He chattered on happily, looking at the Motor all the time, and Overholt
tried to smile and answered him with a word or two now and then, though
he was becoming more and more nervous as the minutes passed and the
supreme moment came nearer. In his own mind he was going over the simple
operations he had to perform to start the engine; yet easy as they were
he was afraid that he might make some fatal mistake. He did not let
himself think of failure; he did not dare to wonder how he should tell
his wife if anything went wrong and all her hard-saved earnings were
lost in the general ruin that must follow if the thing would not move.
There was next to nothing left of what she had sent, now that
everything was paid for; it would support him and the boy for a month,
if so long, but certainly no more.

He was ready at last, but, strange to say, he would gladly have put off
the great moment for half an hour now that there was no reason for
waiting another moment. He sat down again in his chair and folded his
hands.

"Aren't you going to begin, father?" asked Newton. "What are you waiting
for?"

Overholt pulled himself together, rose with a pale face, and laid his
shaking hands on the heavy plate-glass case. It moved upwards by its
chain and counterpoise, almost at a touch, till it was near the low
ceiling, quite clear of the machine.

He was very slow in doing what was still necessary, and the boy watched
him in breathless suspense, for he had seen other trials that had
failed--more than two or three, perhaps half a dozen. Every one who has
lived with an inventor, even a boy, has learned to expect disappointment
as inevitable; only the seeker himself is confident up to a certain
point, and then his own hand trembles, when the moment of trial is
come.

Overholt poured the chemical into the chamber at the base, screwed down
the air-tight plug, and opened the communication between the reservoir
and the machine. Then he took out his watch and waited four minutes,
that being twice the time he had ascertained to be necessary for a
sufficient quantity of the liquid to penetrate into the distributors
beyond. He next worked the hand air-pump, keeping his eye on the vacuum
gauge, and lastly, as soon as the needle marked the greatest exhaustion
he knew to be obtainable, he moved the starting lever to the proper
position, and