aded
men within them. Then that creature, whatever it was, turned away and
vanished.

But Tommy felt a curious shivering horror of the thing. It had moved
soundlessly, without a doubt, because not one of the Ragged Men had
noted its presence. It had been kept away by the fires. But Denham and
Evelyn were somewhere in the tree-fern forest, and they would not dare
to make fires....

Tommy drew away from the dimensoscope, shivering. He had been looking
only, but the place into which he looked was real, and the dangers
that lay hidden there were very genuine, and there was a man and a
girl of his own race and time struggling desperately, without arms or
hope, to survive.

* * * * *

Smithers was casually fitting together an intricate array of little
rings made of copper tubing. There were three of them, and each was
fitted into the next largest by pins which enabled them to spin
noiselessly and swiftly at the touch of Smithers' finger. He had them
spinning now, each in a separate direction, and the effect was
bewildering.

As Tommy watched, Smithers stopped them, oiled the pins carefully, and
painstakingly inserted a fourth ring. Only this ring was of a white
metal that looked somehow more pallid than silver. It had a whiteness
like that of ivory beneath its metallic gleam.

Tommy blinked.

"Did Von Holtz give you that metal?" he asked suddenly.

Smithers looked up and puffed at a short brown pipe.

"Nope. There was some splashes of it by the castin' box. I melted 'em
together an' run a ring. Pressed it to shape; y' can't hammer this
stuff. It goes to water and dries up quicker'n lightning--an' you hold
y'nose an' run. I used it before for the Professor."

Tommy went over to him excitedly. He picked up the little contrivance
of many concentric rings. The big motor was throbbing rhythmically,
and the generator was humming at the back of the laboratory. Von Holtz
was out of sight.

* * * * *

With painstaking care Tommy went over the little device. He looked up.

"A coil?"

"I wound one," said Smithers calmly. "On the lathe. Not so hot, but
it'll do, I guess. But I can't fix these rings like the Professor
did."

"I think I can," said Tommy crisply. "Did you make some wire for
springs?"

"Yeah!"

Tommy fingered the wire. Stout, stiff, and surprisingly springy wire
of the same peculiar metal. It was that metallic ammonium which
chemists have