proper care you can not get into trouble through their possession. And who knows what benefits to humanity may result? One week from to-day, at this hour, I will again appear to you, at which time you shall receive the second series of electrical gifts."
"I'm not sure," said Rob, "that I shall be able again to make the connections that will strike the Master Key."
"Probably not," answered the Demon. "Could you accomplish that, you might command my services forever. But, having once succeeded, you are entitled to the nine gifts – three each week for three weeks – so you have no need to call me to do my duty. I shall appear of my own accord."
"Thank you," murmured the boy.
The Demon bowed and spread his hands in the form of a semi-circle. An instant later there was a blinding flash, and when Rob recovered from it and opened his eyes the Demon of Electricity had disappeared.
CHAPTER FOUR
TESTING THE INSTRUMENTS
There is little doubt that had this strange experience befallen a grown man he would have been stricken with a fit of trembling or a sense of apprehension, or even fear, at the thought of having faced the terrible Demon of Electricity, of having struck the Master Key of the world's greatest natural forces, and finding himself possessed of three such wonderful and useful gifts. But a boy takes everything as a matter of course. As the tree of knowledge sprouts and expands within him, shooting out leaf after leaf of practical experience, the succession of surprises dulls his faculty of wonderment. It takes a great deal to startle a boy.
Rob was full of delight at his unexpected good fortune; but he did not stop to consider that there was anything remarkably queer or uncanny in the manner in which it had come to him. His chief sensation was one of pride. He would now be able to surprise those who had made fun of his electrical craze and force them to respect his marvelous powers. He decided to say nothing about the Demon or the accidental striking of the Master Key. In exhibiting to his friends the electrical devices he had acquired it would be "no end of fun" to mark their amazement and leave them to guess how he performed his feats.
So he put his treasures into his pocket, locked his workshop and went downstairs to his room to prepare for dinner.
While brushing his hair he remembered it was no longer necessary for him to eat ordinary food. He was feeling quite hungry at that moment, for he had a boy's ravenous appetite; but, taking the silver box from his pocket, he swallowed a tablet and at once felt his hunger as fully satisfied as if he had partaken of a hearty meal, while at the same time he experienced an exhilarating glow throughout his body and a clearness of brain and gaiety of spirits which filled him with intense gratification.
Still, he entered the dining-room when the bell rang and found his father and mother and sisters already assembled there.
"Where have you been all day, Robert?" inquired his mother.
"No need to ask," said Mr. Joslyn, with a laugh. "Fussing over electricity, I'll bet a cookie!"
"I do wish," said the mother, fretfully, "that he would get over that mania. It unfits him for anything else."
"Precisely," returned her husband, dishing the soup; "but it fits him for a great career when he becomes a man. Why shouldn't he spend his summer vacation in pursuit of useful knowledge instead of romping around like ordinary boys?"
"No soup, thank you," said Rob.
"What!" exclaimed his father, looking at him in surprise, "it's your favorite soup."
"I know," said Rob, quietly, "but I don't want any."
"Are you ill, Robert?" asked his mother.
"Never felt better in my life," answered Rob, truthfully.
Yet Mrs. Joslyn looked worried, and when Rob refused the roast, she was really shocked.
"Let me feel your pulse, my poor boy!" she commanded, and wondered to find it so regular.
In fact, Rob's action surprised them all. He sat calmly throughout the meal, eating nothing, but apparently in good health and spirits, while even his sisters regarded him with troubled countenances.
"He's worked too hard, I guess," said Mr. Joslyn, shaking his head sadly.
"Oh, no; I haven't," protested Rob; "but I've decided not to eat anything, hereafter. It's a bad habit, and does more harm than good."
"Wait till breakfast," said sister Helen, with a laugh; "you'll be hungry enough by that time."
However, the boy had no desire for food at breakfast time, either, as the tablet sufficed for an entire day. So he renewed the anxiety of the family by refusing to join them at the table.
"If this goes on," Mr. Joslyn said to his son, when breakfast was finished, "I shall be obliged to send you away for your health."
"I think of making a trip this morning," said Rob, carelessly.
"Where to?"
"Oh, I may go to Boston, or take a run over to Cuba or Jamaica," replied the boy.
"But you can not go so far by yourself," declared his father; "and there is no one to go with you, just now. Nor can I spare the money at present for so expensive a trip."
"Oh, it won't cost anything," replied Rob, with a smile.
Mr. Joslyn looked upon him gravely and sighed. Mrs. Joslyn bent over her son with tears in her eyes and said:
"This electrical nonsense has affected your mind, dear. You must promise me to keep away from that horrid workshop for a time."
"I won't enter it for a week," he answered. "But you needn't worry about me. I haven't been experimenting with electricity all this time for nothing, I can tell you. As for my health, I'm as well and strong as any boy need be, and there's nothing wrong with my head, either. Common folks always think great men are crazy, but Edison and Tesla and I don't pay any attention to that. We've got our discoveries to look after. Now, as I said, I'm going for a little trip in the interests of science. I maybe back to-night, or I may be gone several days. Anyhow, I'll be back in a week, and you mustn't worry about me a single minute."
"How are you going?" inquired his father, in the gentle, soothing tone persons use in addressing maniacs.
"Through the air," said Rob.
"Where's your balloon?" inquired sister Mabel, sarcastically.
"I don't need a balloon," returned the boy. "That's a clumsy way of traveling, at best. I shall go by electric propulsion."
"Good gracious!" cried Mr. Joslyn, and the mother murmured: "My poor boy! my poor boy!"
"As you are my nearest relatives," continued Rob, not noticing these exclamations, "I will allow you to come into the back yard and see me start. You will then understand something of my electrical powers."
They followed him at once, although with unbelieving faces, and on the way Rob clasped the little machine to his left wrist, so that his coat sleeve nearly hid it.
When they reached the lawn at the back of the house Rob kissed them all good-by, much to his sisters' amusement, and turned the indicator of the little instrument to the word "up."
Immediately he began to rise
