A NIGHT EXPEDITION.
It was getting near dawn, and the mist was perceptibly clearing away, when the two air-yachts approached the great funnel-shaped opening leading down to the ancient volcano.
Ivanta, who had been wondering how Fumenta was going to keep the promise he had made that he would hide the airships away, looked with great curiosity at the dark, uninviting cavity.
'Are we to try to squeeze in there, friend Fumenta?' he asked. 'Is that your idea?'
For answer the outlaw asked what was the length of the larger of the two vessels, and Ivanta gave him the measurement upon the Martian scale.
'I thought so. Then there is room,' he declared.
And so it turned out. By means of a little manoeuvring, the two vessels were induced to sink slowly through the opening, without touching the sides. And when once through the funnel there was plenty of room for them in the great dome-like space below to rest, all upstanding, on the ground.
Then, upon some metal staging round the base of the funnel, high up in the domed roof, fires were lighted, and upon them, after a time, when they had started a sufficient draught, quantities of sulphur were thrown.
The draught was so great from the maze of underground galleries that all the fumes were carried up into the sky, while below the air was fresh and pure.
'There!' said Fumenta, in well-satisfied tones, when all was in working order, 'those sulphur fumes are carried thousands of feet up into the air. That I know to be the fact, because I have been up to make sure. No airships will come near us—they cannot do so without running the risk of asphyxiating every soul on board!'