the money was gone.

Of course he yielded to the temptation—nay, he never gave the other course a moment's thought. Two thousand pounds would last him for years; and no one could have persuaded him that with complete leisure, freedom from all other concerns, and money for the necessary experiments, he would not have succeeded long before his capital was exhausted.

So he put the money into a bank whence he could draw it out as he chose, and withdrew himself from the world to work out the ideal of his life.

Year after year passed, and still success did not come. He found practice very different from theory, and in a hundred details he met with difficulties he had never seen on paper. Meanwhile his money melted away in costly experiments which only raised hopes that ended in bitter disappointment. His wonderful machine was a miracle of ingenuity, and was mechanically perfect in every detail save one—it would do no practical work.

Like every other inventor who had grappled with the problem, he had found himself constantly faced with that fatal ratio of weight to power. No engine that he could devise would do more than lift itself and the machine. Again and again he had made a toy that would fly, as others had done before him, but a machine that would navigate the air as a steamer or an electric vessel navigated the waters, carrying cargo and passengers, was still an impossibility while that terrible problem of weight and power remained unsolved.

In order to eke out his money to the uttermost, he had clothed and lodged himself meanly, and had denied himself everything but the barest necessaries of life.

Thus he had prolonged the struggle for over five years of toil and privation and hope deferred, and now, when his last sovereign had been changed and nearly spent, success—real, tangible, practical success—had come to him, and the discovery that was to be to the twentieth century what the steam-engine had been to the nineteenth was accomplished.

He had discovered the true motive power at last.

Two liquefied gases—which, when united, exploded spontaneously—were admitted by a clockwork escapement in minute quantities into the cylinders of his engine, and worked the pistons by the expansive force of the gases generated by the explosion. There was no weight but the engine itself and the cylinders containing the liquefied gases. Furnaces, boilers, condensers, accumulators, dynamos—all the ponderous apparatus of steam and electricity—were done away with, and he had a power at command greater than either of them.

There was no doubt about it. The moment that his trembling fingers set the escapement mechanism in motion, the model that embodied the thought and labour of years rose into the air as gracefully as a bird on the wing, and sailed round and round in obedience to its rudder, straining hard at the string which prevented it from striking the ceiling. It was weighted in strict proportion to the load that the full-sized air-ship would have to carry. To increase this was merely a matter of increasing the power of the engine and the size of the floats and fans.

The room was a large one, for the house had been built for a better fate than letting in tenements, and it ran from back to front with a window at each end. Out of doors there was a strong breeze blowing, and as soon as Arnold was sure that his ship was able to hold its own in still air, he threw both the windows open and let the wind blow straight through the room. Then he drew the air-ship down, straightened the rudder, and set it against the breeze.

In almost agonised suspense he watched it rise from the floor, float motionless for a moment, and then slowly forge ahead in the teeth of the wind, gathering speed as it went. It was then that he had uttered that triumphant cry of "Victory!" All the long years of privation and hope deferred vanished in that one supreme moment of innocent and bloodless conquest, and he saw himself master of a kingdom as wide as the world itself.

He let the model fly the length of the room before he stopped the clockwork and cut off the motive power, allowing it to sink gently to the floor. Then came the reaction. He looked steadfastly at his handiwork for several moments in silence, and then he turned and threw himself on to a shabby little bed that stood in one corner of the room and burst into a flood of tears.

Triumph had come, but had it not come too late? He knew the boundless possibilities of his invention—but they had still to be realised. To do this would cost thousands of pounds, and he had just one half-crown and a few coppers. Even these were not really his own, for he was already a week behind with his rent, and another payment fell due the next day. That would be twelve shillings in all, and if it was not paid he would be turned into the street.

As he raised himself from the bed he looked despairingly round the bare, shabby room. No; there was nothing there that he could pawn or sell. Everything saleable had gone already to keep up the struggle of hope against despair. The bed and wash-stand, the plain deal table, and the one chair that comprised the furniture of the room were not his. A little carpenter's bench, a few worn tools and odds and ends of scientific apparatus, and a dozen well-used books—these were all that he possessed in the world now, save the clothes on his back, and a plain painted sea-chest in which he was wont to lock up his precious model when he had to go out.

His model! No, he could not sell that. At best it would fetch but the price of an ingenious toy, and without the secret of the two gases it was useless. But was not that worth something? Yes, if he did not starve to death before he could persuade any one that there was money in it. Besides, the chest and its priceless contents would be seized for the rent next day, and then—

"God help me! What am I to do?"

The words broke from him like a cry of physical pain, and ended in a sob, and for all answer there was the silence of the room and the inarticulate murmur of the streets below coming up through the open windows.

He was weak with hunger and sick with excitement, for he had lived for days on bread and cheese, and that day he had eaten nothing since the crust that had served him for breakfast. His nerves, too, were shattered by the intense strain of his final trial and triumph, and his head was getting light.

With a desperate effort he recovered himself, and the heroic resolution that had sustained him through his long struggle came to his aid again. He got up and poured some water from the ewer into a cracked cup and drank it. It refreshed him for the moment, and he poured the rest of the water over his head. That steadied his nerves and cleared his brain. He took up the model from the floor, laid it tenderly and lovingly in its usual resting-place in the chest. Then he locked the chest and sat down upon it to think the situation over.

Ten minutes later he rose to his feet and said aloud—

"It's no use. I can't think on an empty stomach. I'll go out and have one more good meal if it's the last I ever have in the world, and then perhaps some ideas will come."

So saying, he took down his hat, buttoned his shabby velveteen coat to conceal his lack of a waistcoat, and went out, locking the door behind him as he went.

Five minutes' walk brought him to the Blackfriars Road, and then he turned towards the river and crossed the bridge just as the motley stream of city workers was crossing it in the opposite direction on their homeward journey.

At Ludgate Circus he went into an eating-house and fared sumptuously on a plate of beef, some bread and butter, and a