"workshop"—that he especially delighted. For not only was it the center of all his numerous "lines" throughout the house, but he had rigged up therein a wonderful array of devices for his own amusement. A trolley-car moved around a circular track and stopped regularly at all stations; an engine and train of cars moved jerkily up and down a steep grade and through a tunnel; a windmill was busily pumping water from the dishpan into the copper skillet; a sawmill was in full operation and a host of mechanical blacksmiths, scissors-grinders, carpenters, wood-choppers and millers were connected with a motor which kept them working away at their trades in awkward but persevering fashion.

The room was crossed and recrossed with wires. They crept up the walls, lined the floor, made a grille of the ceiling and would catch an unwary visitor under the chin or above the ankle just when he least expected it. Yet visitors were forbidden in so crowded a room, and even his father declined to go farther than the doorway. As for Rob, he thought he knew all about the wires, and what each one was for; but they puzzled even him, at times, and he was often perplexed to know how to utilize them all.

One day when he had locked himself in to avoid interruption while he planned the electrical illumination of a gorgeous pasteboard palace, he really became confused over the network of wires. He had a "switchboard," to be sure, where he could make and break connections as he chose; but the wires had somehow become mixed, and he could not tell what combinations to use to throw the power on to his miniature electric lights.

So he experimented in a rather haphazard fashion, connecting this and that wire blindly and by guesswork, in the hope that he would strike the right combination. Then he thought the combination might be right and there was a lack of power; so he added other lines of wire to his connections, and still others, until he had employed almost every wire in the room.

Yet it would not work; and after pausing a moment to try to think what was wrong he went at it again, putting this and that line into connection, adding another here and another there, until suddenly, as he made a last change, a quick flash of light almost blinded him, and the switch-board crackled ominously, as if struggling to carry a powerful current.

Rob covered his face at the flash, but finding himself unhurt he took away his hands and with blinking eyes attempted to look at a wonderful radiance which seemed to fill the room, making it many times brighter than the brightest day.

Although at first completely dazzled, he peered before him until he discovered that the light was concentrated near one spot, from which all the glorious rays seemed to scintillate.

He closed his eyes a moment to rest them; then re-opening them and shading them somewhat with his hands, he made out the form of a curious Being standing with majesty and composure in the center of the magnificent radiance and looking down upon him!

2. The Demon of Electricity

Rob was a courageous boy, but a thrill of fear passed over him in spite of his bravest endeavor as he gazed upon the wondrous apparition that confronted him. For several moments he sat as if turned to stone, so motionless was he; but his eyes were nevertheless fastened upon the Being and devouring every detail of his appearance.

And how strange an appearance he presented!

His jacket was a wavering mass of white light, edged with braid of red flames that shot little tongues in all directions. The buttons blazed in golden fire. His trousers had a bluish, incandescent color, with glowing stripes of crimson braid. His vest was gorgeous with all the colors of the rainbow blended into a flashing, resplendent mass. In feature he was most majestic, and his eyes held the soft but penetrating brilliance of electric lights.

It was hard to meet the gaze of those searching eyes, but Rob did it, and at once the splendid apparition bowed and said in a low, clear voice:

"I am here."

"I know that," answered the boy, trembling, "but WHY are you here?"

"Because you have touched the Master Key of Electricity, and I must obey the laws of nature that compel me to respond to your summons."

"I—I didn't know I touched the Master Key," faltered the boy.

"I understand that. You did it unconsciously. No one in the world has ever done it before, for Nature has hitherto kept the secret safe locked within her bosom."

Rob took time to wonder at this statement.

"Then who are you?" he inquired, at length.

"The Demon of Electricity," was the solemn answer.

"Good gracious!" exclaimed Rob, "a demon!"

"Certainly. I am, in truth, the Slave of the Master Key, and am forced to obey the commands of any one who is wise and brave enough—or, as in your own case, fortunate and fool-hardy enough—to touch it."

"I—I've never guessed there was such a thing as a Master Key, or—or a Demon of Electricity, and—and I'm awfully sorry I—I called you up!" stammered the boy, abashed by the imposing appearance of his companion.

The Demon actually smiled at this speech,—a smile that was almost reassuring.

"I am not sorry," he said, in kindlier tone, "for it is not much pleasure waiting century after century for some one to command my services. I have often thought my existence uncalled for, since you Earth people are so stupid and ignorant that you seem unlikely ever to master the secret of electrical power."

"Oh, we have some great masters among us!" cried Rob, rather nettled at this statement. "Now, there's Edison—"

"Edison!" exclaimed the Demon, with a faint sneer; "what does he know?"

"Lots of things," declared the boy. "He's invented no end of wonderful electrical things."

"You are wrong to call them wonderful," replied the Demon, lightly. "He really knows little more than yourself about the laws that control electricity. His inventions are trifling things in comparison with the really wonderful results to be obtained by one who would actually know how to direct the electric powers instead of groping blindly after insignificant effects. Why, I've stood for months by Edison's elbow, hoping and longing for him to touch the Master Key; but I can see plainly he will never accomplish it."

"Then there's Tesla," said the boy.

The Demon laughed.

"There is Tesla, to be sure," he said. "But what of him?"

"Why, he's discovered a powerful light," the Demon gave an amused chuckle, "and he's in communication with the people in Mars."

"What people?"

"Why, the people who live there."

"There are none."

This great statement almost took Rob's breath away, and caused him to stare hard at his visitor.

"It's generally thought," he resumed, in an annoyed tone, "that Mars has inhabitants who are far in advance of ourselves in civilization. Many scientific men think the people of Mars have been trying to signal us for years, only we don't understand their signals. And great novelists have written about the Martians and their wonderful civilization, and—"

"And they all know as much about that little planet as you do yourself," interrupted the Demon, impatiently. "The trouble with you Earth people is that you delight in guessing about what you can not know. Now I happen to know all about Mars, because I can traverse all space and have had ample leisure to investigate the different planets. Mars is not peopled at all, nor is any other of the planets you recognize in the heavens. Some contain low orders of beasts, to be sure, but Earth alone has an intelligent, thinking, reasoning population, and your scientists and novelists would do better trying to comprehend their own planet than in groping through space to unravel the mysteries of barren and unimportant worlds."

Rob listened to this with surprise and disappointment; but he reflected that the Demon ought to know what he