ic effort, he flung off the luminous drops, rubbed his hand on
his garments, and got it back into its fur mitten.

"Gee, it's cold!" he muttered. "Freeze the horns off a brass
billy-goat!"

"Cold light!" I exclaimed. "What wouldn't a bottle of that stuff be
worth to a chemist back in the States!"

"That cone must be a factory to make the stuff." Ray suggested,
hugging his hand. "They might pump the liquid up to the top, and then
let it trickle down over the sides: that would explain why the cone is
so bright. The stuff might absorb sunlight, like barium sulphide. And
there could be chemical action with the air, under the actinic rays."

"Well, if somebody's making cold light, where does he use it?"

"I'd like to find out, and strike him for a hot meal," Ray said,
grinning. "It's too cold to live on top of the ground around here.
They must run it down in a cave."

"Then let's find the hole."

"You know it's possible we won't be welcome. This mountain of light
may be connected with the vanishing of all the aviators. We'd better
take along the rifle."

* * * * *

We set off around just outside the white metal wall. The snow and ice
was irregularly banked against it, but the wall itself was smooth and
unbroken. We had limped along for some two miles, or more than halfway
around the amazing lake of light. I had begun to doubt that we would
find anything.

Then we came to a square metal tower, ten feet on a side, that rose
just outside the silvery wall, to a level with its top. The ice was
low here; the tower rose twenty feet above its unequal surface. We
found metal flanges riveted to its side, like the steps of a ladder.
They were most inconveniently placed, nearly four feet apart; but we
were able to climb them, and to look down the shaft.

It was a straight-sided pit, evidently some hundreds of feet deep. We
could see a tiny square of light at the bottom, very far away. The
flanges ran down the side forming the rungs of a ladder that gave
access to whatever lay at the bottom.

Without hesitation, Ray climbed over the side and started down. I
followed him, feeling a great relief in getting out of the freezing
wind. Ray had the rifle and ammunition strapped to his back, along
with a few other articles; and I had a small pack. We had abandoned
the sledge, with the useless stove and the most of our instruments.
Our food was all gone.

The metal flanges were fully four feet apart