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 into the air.
"Don't worry about me!" he called down to them. "Good-by!"
Mrs. Joslyn, with a scream of terror, hid her face in her hands.
"He'll break his neck!" cried the astounded father, tipping back his head to look after his departing son.
"Come back! Come back!" shouted the girls to the soaring adventurer.
"I will--some day!" was the far-away answer.
Having risen high enough to pass over the tallest tree or steeple, Rob put the indicator to the east of the compass-dial and at once began moving rapidly in that direction.
The sensation was delightful. He rode as gently as a feather floats, without any exertion at all on his own part; yet he moved so swiftly that he easily distanced a railway train that was speeding in the same direction.
"This is great!" reflected the youth. "Here I am, traveling in fine style, without a penny to pay any one! And I've enough food to last me a month in my coat pocket. This electricity is the proper stuff, after all! And the Demon's a trump, and no mistake. Whee-ee! How small everything looks down below there. The people are bugs, and the houses are soap-boxes, and the trees are like clumps of grass. I seem to be passing over a town. Guess I'll drop down a bit, and take in the sights."
