would have given anything to be alone. He was overwrought by the long strain that had so often seemed unbearable, and when the liquid that was heating had reached the right temperature and the iron pot had to be taken off the stove, his hands shook so that he nearly dropped it; but Newton did not see that.
"It's wonderful how everything has come out just right!" the boy exclaimed as he looked at the machine. "Out of your three wishes you'll get two, father, for the wheel will go round and I'm going to have a regular old patent, double-barrelled Christmas with a gilt edge!" His similes were mixed, but effective in their way. "And you'll probably get the other wish in half a shake now, for mother'll come right home, won't she?"
"If the trial succeeds," Overholt said, still instinctively seeking to forestall a disappointment he did not expect. "Nothing is a fact until it has happened, you know!"
"Well," said Newton, "if I had anything to bet with, and somebody to bet against, I'd bet, that's all. But I haven't. It's a pity too, now that everything's coming out right. Do you remember how we were trying to make bricks without straw less than a month ago, 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 then stepped back to watch the result.
For a moment, in the joy of anticipation, a strange light illuminated his face, his lips parted as in a foretasted wonder, and he forgot even to drop the hand he had just withdrawn. The boy held his breath unconsciously till he was nearly dizzy.
Then a despairing cry burst from the wretched man's lips, he threw up his hands as if he had been shot through the heart, and stumbled backwards.
The Motor stood still, motionless as ever, and gleaming under the brightly shining lamps.
"Oh, Helen! God forgive me!"
With the words he fell heavily to the floor, and lay there, a nerveless, breathless heap. Newton was kneeling beside him in an instant.
"Father!" cried the boy in agony, bending over the still white face. "Father! Speak to me! You can't be dead—you can't—"
In his mortal terror the lad held each breath till it seemed as if his head must burst, then breathed once and shut his lips again with all his strength. Some instinct made him lay his ear to the man's chest to listen for the beatings of his heart, but he could hear nothing.
Half-suffocated with sudden mingled grief and fright, he straightened himself on his knees and looked up at the cursed machine that had wrought such awful destruction.
Then he in turn uttered a cry, but it was low and full of wonder, long drawn out and trembling as the call of a frightened young wild animal.
The thing was moving, steadily, noiselessly moving in the bright light; the double levers worked like iron jaws opening and shutting regularly, the little valve-rods rose and sank, and the heavy wheel whirled round and round. The boy was paralysed with amazement, and for ten seconds he forgot that he was kneeling beside his father's fallen body on the floor; then he felt it against him and it was no longer quite still.
Overholt groaned and turned upon his side as his senses slowly came back and his agony tortured him to life again. Instantly the boy bent over him.
"Father! It's going! Wake up, father! The wheel's going round at last!"
IX
HOW THE KING OF HEARTS MADE A FEAST IN THE CITY OF HOPE
When Overholt understood what he heard, he opened his eyes and looked up into his son's face, moving his head mournfully from side to side as it lay on the boards. But suddenly he caught sight of the engine. He gasped for breath, his jaw dropped, and his eyes were starting from their sockets as he struggled to get up with 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
