Jimmy was past speech by this time and could only look at his comrades in helpless wonder. Then the twang of a banjo sounded through the rooms and to the thrumming of the strings came a voice in rich negro dialect
"It rained all night the day I left,
The next day it was dry,
The sun so hot I froze to death
Susanna, don't you cry."
CHAPTER IV
MYSTERIOUS FORCES
The boys broke out in roars of laughter in which the doctor joined heartily.
"You see how it is," he said, as the song came to an end. "There's hardly anything you can think of that you can't hear over the wireless telephone. It takes you anywhere you want to go in a fraction of a second. In the last few minutes, we've covered quite a section of the United States, and with a still stronger instrument we could go right out to the Pacific coast and hear the barking of the sea lions at the Golden Gate."
"Wonder if we could hear the barking of the hot dogs at Coney Island," whispered the irrepressible Herb, who would have his joke.
Bob nudged him sharply and Herb subsided.
"And you can pick out any kind of entertainment you want," the doctor went on. "The great stations from which this music was sent out have programs which are published every day, together with the exact time that the selections will be given. At a given minute you can make your adjustment and listen to a violin solo, a band concert, a political speech, a sermon, or anything else that you want. If it doesn't please you, you can shut it off at once, which is much easier and pleasanter than getting up and going out from an audience.
"We'll have some more selections later on in the evening," he continued, "but now I want to explain to you how this thing is done. I can't hope to do much more than touch the surface of the subject to-night, for I don't want to tire you out, and there'll be plenty of other nights and days when I hope you boys will call upon me for any information that you want and I can give.