you have escaped the latter, unless, indeed, God has helped those who have
so wisely helped themselves?"

"Your last thought is right," answered our friend. "Nature has certainly
assisted us. While the crust of the planet was thin we know the central
fires heaved and shook the ground and burst forth from the mountains,
causing great destruction and keeping the world in fear. We do not know
how thick the crust of the planet now is, but nothing has been felt of
those inner convulsions for many ages. One of our feats of engineering has
been to see how far we could penetrate into the surface of the globe. A
well of vast size has been dug, the temperature being carefully noted and
observations made of the many different substances passed through--water,
coal, gas, oil, and all kinds of mineral deposits. The work has progressed
from one generation to another, and no one can tell when it will be called
finished, as it is determined to dig toward the center of the planet as
fast as our ever-increasing skill will permit."

"Did you find out how thick the crust is?" I asked.

"No," he answered, "we are not much nearer the solution of that question
than before, but we have made valuable discoveries as to what the crust is
composed of. The temperature has gradually, though slowly, increased, and
we believe the time will come when the work will have to be abandoned on
account of the heat. We have gone far enough to know that when the fuel on
the surface of our globe is all used up we shall only have to tap the
center to get all the heat we want." "What a capital idea that will be," I
interrupted, "to throw at some of our pessimistic friends on the earth,
Doctor."

"We see now, Thorwald," my companion said, "that your planet is too old to