It seemed that these outlaws were without flying apparatus of any kind except the roughest sort of wings. They lived the life of hunted men, and even if they had possessed airships or other flying machines, they were without the necessary means of utilising them.
All kinds of air-craft required electricity to work them; which, in its turn, as with us, required machinery to produce it. Throughout Ivanta's dominions there were stations here and there at which passing aeronauts could refill their storage batteries on payment of certain specified sums. At these stations gigantic engines of immense power were ever at work, day and night, accumulating the necessary force, and it was upon this constant supply that all airships were dependent. When they journeyed beyond the districts in which these stations were situated, travellers were compelled to be careful not to venture too far afield—no farther, that is, than they could travel back again with the storage power on board.
For the same reason, the outlaws had none of the usual weapons—those tridents which wielded such strange, mysterious power; or, if they possessed any, they were useless to them for want of the needful force.
Throughout the inhabited portion of the planet the same state of things prevailed. There were no small weapons other than the tridents, save swords, spears, and the like. Nor were there any large weapons like our cannon and big guns. Owing to their great weight, all such contrivances had long ago been abandoned as too heavy to be carried in the air, and as being no longer of any use on the ground. An airship depended for its means of offence either upon ramming an adversary, or being able to get above it, and drop upon it bombs, which, upon bursting, produced a similar effect upon living beings around it to that of the tridents—that is to say, they rendered them for the time being unconscious. Thus, warfare in the air resolved itself chiefly into a manoeuvring contest, the one which could soar uppermost, and get exactly over its adversary, usually—other things being equal—gaining the advantage.
Having no machinery for the production of electricity, and consequently no flying apparatus save the clumsy, slow wings without motors, Fumenta and the bands of which he was chief were for the most part restricted in their operations to nocturnal expeditions. They seldom ventured abroad in the daytime, but remained hidden in their underground retreats.
Fortunately for their purpose, their leader had discovered, amid the arid wilderness of rocky mountains into which he had been driven, an extinct volcano with an ancient crater open to the sky. Within was the immense cavity which they had made their chief hiding-place, and running into it from all points of the compass were endless galleries and passages—a veritable labyrinth which extended for miles in every direction. These led to numerous underground grottos, large and lofty caverns, which they had turned into dwelling-places. The whole formed a sort of subterranean town.
Not the least remarkable thing about this retreat was the ingenious ruse by which Fumenta had kept its existence unknown to his enemies. He had discovered, in some of the lower galleries, considerable accumulations of sulphur, and whenever, during the daytime, the approach of airships was signalled by his scouts, he had sulphur fires lighted in the crater just beneath the funnel-like opening, sending up columns of smoke and sulphur fumes.
As a consequence, the report had gone forth that the supposedly extinct volcano had become active again, and its neighbourhood was shunned as dangerous by all not in the secret. A few venturesome inquirers, who had attempted to make explorations, had been baffled by the sulphur fumes, and had returned declaring that there were evident signs of renewed volcanic activity.
Similarly, if, as sometimes happened, an occasional airship, driven out of her course by high winds, passed near the place at night, and saw a light coming up through the opening, it was put down to the same cause.
These notes are necessary to explain the events which follow.