mer about to dive
into icy cold water.

Turning back to one of the benches, he picked up a wooden funnel-rack,
and tossed it to the crystal disk beneath the violet ray. Slowly it
decreased in size, until it had vanished from sight.

"Safe, I suppose," he muttered. "But how do I know when I'm small
enough?"

* * * * *

After a moment he picked up a glass bottle which measured about three
inches in height, set it on the floor, beside the crystal disk.

"I dive out when I get to be the size of the bottle," he murmured.

With that, he leaped into the violet beam.

He felt no unusual sensation, except one of pleasant, tingling warmth,
as if the direct rays of the sun were bearing down upon him. For a
moment he feared that his size was not being affected. Then he
noticed, not that he appeared to become smaller, but that the
laboratory seemed to be growing immensely larger.

The walls seemed to race away from him. The green-blue sphere of the
tiny planet which he proposed to visit expanded and drew away above
his head.

Abruptly fearful, alarmed at the hugeness of the room, he turned to
look at the bottle he had placed to serve as a standard of size. It
had grown with everything else, until it seemed to be about three feet
high.

And it was swiftly expanding. It reached to the level of his shoulder.
And higher!

He ran to the edge of the crystal disk, which now seemed a floor many
yards across, and leaped from its edge. It was a dozen steps to where
he had left the bottle. And it was as tall as himself!

He started across the floor of the laboratory toward the table under
which the toy plane stood. The incredible immensity of his
surroundings awed him strangely. The walls of the room seemed distant,
Cyclopean cliffs; the roof was like a sky. Table legs towered up like
enormous columns.

It seemed a hundred yards across the strangely rough floor to the
plane. As he drew near it, it gave him huge satisfaction to see that
it was of normal size, correctly proportioned to his own dimensions.

"Great luck," he muttered, "that I can fly!"

* * * * *

He paused, as he reached the cabin's open door, to wonder at the
astounding fact that a little while ago he had opened that door with a
hand larger than his entire body now was.

"I guess this is my day of wonders!" he muttered. "Allah knows I had
to wait long enough for it!"

First he examined the wea