The speed was gradually increased, and the "Albatross," heading to the southwest, returned at moderate speed towards the Chatham Islands.

"Tom," said Robur, "It is about two hours and a half since we got adrift. The wind has not changed all the time. I think we ought to be over the island in an hour."

"Yes, sir. We are going about forty feet a second. We ought, to be there about half-past three."

"All the better. It would suit us best to get back while it is dark, and even beach the "Albatross" if we can. Those fellows will fancy we are a long way off to the northward, and never think of keeping a look-out. If we have to stop a day or two on the island --"

"We'll stop, and if we have to fight an army of natives?"

"We'll fight," said Robur. "We'll fight then for our "Albatross.""

The engineer went forward to the men, who were waiting for orders. "My lads," he said to them, "we cannot knock off yet. We must work till day comes."

They were all ready to do so. The stern-screw had now to be treated as the other had been. The damage was the same, a twisting from the violence of the hurricane during the passage across the southern pole.

But to get the screw on board it seemed best to stop the progress of the aeronef for a few minutes, and even to drive her backwards. The engines were reversed. The aeronef began to fall astern, when Tom Turner was surprised by a peculiar odor.

This was from the gas given off by the match, which had accumulated in the box, and was now escaping from the cabin. "Hallo!" said the mate, with a sniff.

"What is the matter?" asked Robur.

"Don't you smell something? Isn't it burning powder?"

"So it is, Tom."

"And it comes from that cabin."

Yes, the very cabin --"

"Have those scoundrels set it on fire?"

"Suppose it is something else!" exclaimed Robur. "Force the door, Tom; drive in the door!"

But the mate had not made one step towards it when a fearful explosion shook the "Albatross." The cabins flew into splinters. The lamps went out. The electric current suddenly failed. The darkness was complete. Most of the suspensory screws were twisted or broken, but a few in the bow still revolved.

At the same instant the hull of the aeronef opened just behind the first deck-house, where the engines for the fore-screw were placed; and the after-part of the deck collapsed in space.

Immediately the last suspensory screw stopped spinning, and the "Albatross" dropped into the abyss.

It was a fall of ten thousand feet for the eight men who were clinging to the wreck; and the fall was even faster than it might have been, for the fore propeller was vertical in the air and still working!

It was then that Robur, with extraordinary coolness, climbed up to the broken deck-house, and seizing the lever reversed the rotation, so that the propeller became a suspender. The fall continued, but it was checked, and the wreck did not fall with the accelerating swiftness of bodies influenced solely by gravitation; and if it was death to the survivors of the "Albatross" from their being hurled into the sea, it was not death by asphyxia amid air which the rapidity of descent rendered unbreathable.

Eighty seconds after the explosion, all that remained of the "Albatross" plunged into the waves!

Chapter XXI

THE INSTITUTE AGAIN

Some weeks before, on the 13th of June, on the morning after the sitting during which the Weldon Institute had been given over to such stormy discussions, the excitement of all classes of the Philadelphia population, black or white, had been much easier to imagine than to describe.

From a very early hour conversation was entirely occupied with the unexpected and scandalous incident of the night before. A stranger calling himself an engineer, and answering to the name of Robur, a person of unknown origin, of anonymous nationality, had unexpectedly presented himself in the club-room, insulted the balloonists, made fun of the aeronauts, boasted of the marvels of machines heavier than air, and raised a frightful tumult by the remarks with which he greeted the menaces of his adversaries.