As they drew nearer a fresh burst of firing, this time from the bridge itself, showed that two guns had been dragged on to the railway track to command a better range of the approaching airship. But this attempt, like the rest, was in vain, for the shells flew harmlessly below the car, and, even had they been able to reach it, an ascent of fifty feet or so more would have placed the dirigible but of danger again. Only an anti-aircraft gun, firing at right angles to its base, could hit the terrible war machine above.
All this time Lawless was waiting for his opportunity—and at last it came. Springing forward, he seized one of the hand grenades and flung it with all his strength at the gas-bag above his head, hoping that it would explode and ignite the gas. Unfortunately, it struck a girder below the balloon, but in doing so ignited some of the cordage, which, being creosoted, began to burn furiously.
The commander, realising the danger—for the cordage passed over the gas envelope and must soon ignite it—gave some orders, and while several of the crew climbed up in order to try and put out the burning ropes others rushed upon Lawless.
The latter, however, had managed to seize another grenade, and, holding it high above his head, threatened to hurl it amongst them if they advanced another step. While they stood hesitating, and the commander himself seemed uncertain what to do, there came a wild cry from the men who had climbed into the airship's rigging.
Looking up, the Lieutenant saw that, in spite of all efforts, the ropes were still burning. In a few seconds the fire must spread to the balloon, and that meant annihilation.
The commander sprang to a lever, pulled it, and next moment the dirigible began to descend. He had opened the gas valve in the wild hope that the airship might sink to the water safely before the threatened explosion took place. It was their one chance of escape from a terrible death.
Slowly, very slowly, the monster dirigible descended. Everybody had forgotten Lawless in the horror of the threatened calamity, and all eyes were turned towards the smouldering cords, which occasionally burst into flame in the upward rush of wind caused by the airship's descent.
Would they reach the water before the explosion took place? That was the question each man asked himself.
Cork life-belts were hurriedly served out to the crew, who stood by the rails of the car ready to spring out as soon as the distance rendered it moderately safe. Yet all the time the little wisps of flame rose faster and faster, sometimes disappearing, only to be fanned into life again by the draught of air. Masses of charred and smouldering rope fell on the deck from time to time and were promptly flung overboard.
Nearer and nearer to the water sank the airship, and nearer and nearer to the gas holder reached the flames. Now they were not more than a hundred feet above the water; a few more moments would decide their fate. It was a race between the sinking dirigible and the flames, the odds in favour of the flames.