edestals, and between them a disk of some
unknown composition, mounted in a vertical plane and revolving at
inconceivable velocity. The power was taken from the shaft of this
revolving disk and reduced in speed by means of gear-wheels before being
conveyed to the dynamo. The prongs of the big tuning-forks continued to
vibrate strongly, and gave out in unison the loud, humming note that had
originally attracted Constans's attention. It was undoubtedly, a form of
motor whose power was derived from some secret property of vibratory
bodies, a recondite subject to which his books alluded but obscurely.
Yet in the years immediately preceding the Great Change the principle
seems to have been reduced to practical utility. Here was the engine in
actual operation, and whatever its source of fuel supply or the ultimate
secret of its energy there could be no doubt about its production of
power. It moved, it was alive, and Constans gazed upon it with
fascinated eyes.

The priest had risen to his feet; he touched Constans lightly on the
shoulder.

"The presence chamber," he said, in a whisper. "Come, that you may look
upon the face of the Shining One; he will rejoice in knowing that there
is left even one faithful in Doom."

He opened a door leading to a room at the left of the main hall and
motioned Constans to enter. The door closed behind them and they stood
in darkness. Then came the click of a switch-key, and out of the
blackness faint lines of radiance appeared, changing slowly to a fiery
brightness. And as the lines grew visible they resolved themselves into
the semblance of a great and terrible face, the countenance of a man of
heroic size with long hair. There was no suggestion of a body, only that
majestic head crowned with hyacinthine locks and limned in lambent fire.

Constans felt his knees shaking under him, and involuntarily he
prostrated himself; then again he heard the switch click, and the vision
faded into nothingness.

There was the sound of a shutter being thrown back, and the daylight
streamed in. He rose uncertainly to his feet and looked about him.

It was a small apartment, low-studded, with cement walls and a tiled
floor. Near the door and fastened against the wall was a wooden
framework, bearing a complicated arrangement of push-buttons and levers.
Constans had seen its like pictured in his books, and he instantly
conjectured it to be an electrical switch-board, designed to control and
direct the cur