"Orrin—the sphere!" Phaestra, slightly embarrassed by Frank's stare, clapped her hands.
At her command, Orrin, who had stood quietly by, stepped to the wall and manipulated some mechanism that was hidden by the hangings. There was a musical purr from beneath the floor, and, through a circular opening which appeared as if by magic, there rose a crystal sphere of some four feet in diameter. Slowly it rose until it reached the level of their eyes and there it came to rest. The empress raised her hands as if in invocation and the soft glow of the lights died down, leaving them in momentary darkness. There came a slight murmur from the sphere, and it lighted with the eery green flickerings they had observed in the dome of silver.
ascinated by the weaving lights within, they gazed into the depths of the crystal with awed expectancy. Phaestra spoke.
"Men from the surface," she said, "you, Frank Rowley, and you, Arnold Thompson, are about to witness the powers of that hemisphere of metal you were pleased to term 'Silver Dome.' As you rightly surmised, the dome is of silver—mostly. There are small percentages of platinum, iridium, and other elements, but it is more than nine-tenths pure silver. To you of the surface the alloy is highly valuable for its intrinsic worth by your own standards, but to us the value of the dome lies in its function in revealing to us the past and present events of our universe. The dome is the 'eye' of a complicated apparatus which enables us to see and hear any desired happening on the surface of the earth, beneath its surface, or on the many inhabited planets of the heavens. This is accomplished by means of extremely complex vibrations radiated from the hemisphere, these vibrations penetrating earth, metals, buildings, space itself, and returning to our viewing and sound reproducing spheres to reveal the desired past or present occurrences at the point at which the rays of vibrations are directed.
n order to view the past on our own planet, the rays, which travel at the speed of light, are sent out in a huge circle through space, returning to earth after having spent the requisite number of years in transit. Instantaneous effect is secured by a connecting beam that ties together the ends of the enormous arc. This, of course, is beyond your comprehension, since the Ninth Dimension is involved. When it is desired that events of the present be observed, the rays are projected direct. The future can not be viewed, since, in order to accomplish this, it would be necessary that the rays travel at a speed greater than that of light, which is manifestly impossible."
"Great guns!" gasped Frank. "This crystal sphere then, is capable of bringing to our eyes and ears the happenings of centuries past?"