ious mechanisms, I
repeat, it was, it could be, no other than electricity. But from what
source did his batteries get their power? Had he somewhere an
electric factory, to which he must return? Were the dynamos, perhaps
working in one of the caverns of this hollow?

The result of my examination was that, while I could see that the
machine used wheels and turbine screws and wings, I knew nothing of
either its engine, nor of the force which drove it. To be sure, the
discovery of this secret would be of little value to me. To employ it
I must first be free. And after what I knew--little as that really
was--the Master of the World would never release me.

There remained, it is true, the chance of escape. But would an
opportunity ever present itself? If there could be none during the
voyages of the "Terror," might there possibly be, while we remained
in this retreat?

The first question to be solved was the location of this hollow. What
communication did it have with the surrounding region? Could one only
depart from it by a flying-machine? And in what part of the United
States were we? Was it not reasonable to estimate, that our flight
through the darkness had covered several hundred leagues?

There was one very natural hypothesis which deserved to be
considered, if not actually accepted. What more natural harbor could
there be for the "Terror" than the Great Eyrie? Was it too difficult
a flight for our aviator to reach the summit? Could he not soar
anywhere that the vultures and the eagles could? Did not that
inaccessible Eyrie offer to the Master of the World just such a
retreat as our police had been unable to discover, one in which he
might well believe himself safe from all attacks? Moreover, the
distance between Niagara Falls and this part of the Blueridge
Mountains, did not exceed four hundred and fifty miles, a flight
which would have been easy for the "Terror."

Yes, this idea more and more took possession of me. It crowded out a
hundred other unsupported suggestions. Did not this explain the
nature of the bond which existed between the Great Eyrie and the
letter which I had received with our commander's initials? And the
threats against me if I renewed the ascent! And the espionage to
which I had been subjected! And all the phenomena of which the Great
Eyrie had been the theater, were they not to be attributed to this
same cause--though what lay behind the phenomena was not yet clear?
Yes, the Great Eyrie!