utonic laboratories will be a
scientific adventure of great difficulty and expense. Yet, if carried
on in connection with the work of existing mines and borings it may
mark the coming decade as one of the important epochs in man's attempt
to understand the earth.

"These Plutonic laboratories, placed at various depths under the
surface, fully equipped with modern scientific apparatus, and
maintained indefinitely, will contribute to our knowledge in a dozen
important fields of geophysic and astronomy."

What Prof. Shapley pointed to as merely a possible by-product of the
proposed scientific "descent into Hades" is the commercial possibility
of tapping the earth's internal source of heat. There is 31,000,000
times as much natural heat in the earth than in all the coal resources
of the world. He stated that Sir Charles Parsons and John L. Hodgson,
both noted British engineers, are already engaged in work on this
problem.

When Caverns Yawned

_By Captain S. P. Meek_

[Illustration: From the bump on the side of the submarine came a flash
of red light.]

[Sidenote: Only Dr. Bird's super-scientific sleuthing stands in the
way of Ivan Saranoff's latest attempt at wholesale destruction.]

Bells jangled discordantly. A whistle split the air with a piercing
note. A band blared away on the platform. With a growing rumble of
sound, the Presidential special slowly gathered headway. The President
waved a final farewell to the crowds at the platform and sat down. He
chatted cheerily with his companions until the train was clear of
Charleston, then rose, and with a word to the others stepped into the
car. Operative Carnes of the United States Service slumped back in
his chair with a sigh of relief.

"Thank Goodness, that's over," he said. "I was never so glad to get
him safely away from a place in my life."

Haggerty of the secret service nodded in agreement. Colonel Holmes,
the military aide, looked up inquiringly.

"Why so? Do you think Charleston an especially dangerous place for him
to be?"

"Not ordinarily. Charleston is a very patriotic and loyal city, but I
have been worried. There have been vague rumors going around. Nothing
definite that we could pin down, but enough to make me pretty uneasy."

"I think you've worried needlessly. I have been in constant touch with
the Military Intelligence Division and they have reported nothing
alarming."

Haggerty chuckled at the look of disgust that spread over Car