rical devices with some amusement. They seemed tame beside the
wonders now in his possession; yet he recollected that his numerous
wires had enabled him to strike the Master Key, and therefore should
not be despised.

Before long he noticed a quickening in the air, as if it were suddenly
surcharged with electric fluid, and the next instant, in a dazzling
flash of light, appeared the Demon.

"I am here!" he announced.

"So am I," answered Rob. "But at one time I really thought I should
never see you again. I've been--"

"Spare me your history," said the Demon, coldly. "I am aware of your
adventures."

"Oh, you are!" said Rob, amazed. "Then you know--"

"I know all about your foolish experiences," interrupted the Demon,
"for I have been with you constantly, although I remained invisible."

"Then you know what a jolly time I've had," returned the boy. "But why
do you call them foolish experiences?"

"Because they were, abominably foolish!" retorted the Demon, bitterly.
"I entrusted to you gifts of rare scientific interest--electrical
devices of such utility that their general adoption by mankind would
create a new era in earth life. I hoped your use of these devices
would convey such hints to electrical engineers that they would quickly
comprehend their mechanism and be able to reproduce them in sufficient
quantities to supply the world. And how do you treat these marvelous
gifts? Why, you carry them to a cannibal island, where even your crude
civilization has not yet penetrated!"

"I wanted to astonish the natives," said Rob, grinning.

The Demon uttered an exclamation of anger, and stamped his foot so
fiercely that thousands of electric sparks filled the air, to disappear
quickly with a hissing, crinkling sound.

"You might have astonished those ignorant natives as easily by showing
them an ordinary electric light," he cried, mockingly. "The power of
your gifts would have startled the most advanced electricians of the
world. Why did you waste them upon barbarians?"

"Really," faltered Rob, who was frightened and awed by the Demon's
vehement anger, "I never intended to visit a cannibal island. I meant
to go to Cuba."

"Cuba! Is that a center of advanced scientific thought? Why did you
not take your marvels to New York or Chicago; or, if you wished to
cross the ocean, to Paris or Vienna?"

"I never thought of those places," acknowledged Rob, meekly.

"Then you were foolish, as I said," decl