Another building whose fundamental note was the same began to "sing" in its turn, just as one tuning fork produces sympathetic sounds in a similar distant one.
A few more turns of the wheel and the "singing" stopped. As he continued turning the wheel of the generator, the latter gave out sounds sharper and sharper, higher and higher, shriller and shriller, till the shrieking became unendurable.
And then, suddenly, all sound stopped abruptly.
The frequency had passed over twenty thousand, at which point the human ear ceases to hear sounds.
Ralph turned the wheel a few more notches and then stopped. Except for the flying iron pieces, there was no sound. Even the myriads of sparks leaping around were strangely silent, except for the hissing noise of flames streaming from sharp metal points.
Ralph looked at the clock. It was exactly ten minutes after the first sounding of the gong. He then turned the wheel one notch further and instantly the room was plunged into pitch-black darkness.
To anyone unacquainted with the tremendous force under the control of Ralph 124C 41 +, but having the temerity to insulate himself and stand on a nearby roof there would have been visible an unusual sight. He would also have undergone some remarkable experiences.
The uninitiated stranger standing—well insulated—on a roof not very far off from Ralph's laboratory, would have witnessed the following remarkable phenomena: