And between themselves Uncle Prudent and Phil Evans could not but admire it, although they were quite disposed to deny the evidence of their senses. Chapter XVIII OVER THE VOLCANO _____
The sea was as rough as ever, and the symptoms became alarming.
The barometer fell several millimeters.
The wind came in violent gusts, and then for a moment or so failed altogether.
Under such circumstances a sailing vessel would have had to reef in her topsails and her foresail.
Everything showed that the wind was rising in the northwest.
The storm-glass became much troubled and its movements were most disquieting.
At one o'clock in the morning the wind came on again with extreme violence.
Although the aeronef was going right in its teeth she was still making progress at a rate of from twelve to fifteen miles an hour.
But that was the utmost she could do.
Evidently preparations must be made for a cyclone, a very rare occurrence in these latitudes.
Whether it be called a hurricane, as in the Atlantic, a typhoon, as in Chinese waters a simoom, as in the Sahara, or a tornado, as on the western coast, such a storm is always a gyratory one, and most dangerous for any ship caught in the current which increases from the circumference to the center, and has only one spot of calm, the middle of the vortex.
Robur knew this.
He also knew it was best to escape from the cyclone and get beyond its zone of attraction by ascending to the higher strata.
Up to then he had always succeeded in doing this, but now he had not an hour, perhaps not a minute, to lose.
In fact the violence of the wind sensibly increased.
The crests of the waves were swept off as they rose and blown into white dust on the surface of the sea.
It was manifest that the cyclone was advancing with fearful velocity straight towards the regions of the pole.
"Higher!" said Robur.
"Higher it is," said Tom Tumor.
An extreme ascensional power was communicated to the aeronef, and she shot up slantingly as if she was traveling on a plane sloping downwards from the southwest.
Suddenly the barometer fell more than a dozen millimeters and the "Albatross" paused in her ascent.
What was the cause of the stoppage?
Evidently she was pulled back by the air; some formidable current had diminished the resistance to the screws.
When a steamer travels upstream more work is got out of her screw than when the water is running between the blades.
The recoil is then considerable, and may perhaps be as great as the current.
It was thus with the "Albatross" at this moment.
But Robur was not the man to give in.
His seventy-four screws, working perfectly together, were driven at their maximum speed.
But the aeronef could not escape; the attraction of the cyclone was irrestible.
During the few moments of calm she began to ascend, but the heavy pull soon drew her back, and she sunk like a ship as she founders.
Evidently if the violence of the cyclone went on increasing the
"Albatross" would be but as a straw caught in one of those whirlwinds that root up the trees, carry off roofs, and blow down walls.
Robur and Tom could only speak by signs.
Uncle Prudent and Phil Evans clung to the rail and wondered if the cyclone was not playing their game in destroying the aeronef and with her the inventor--and with the inventor the secret of his invention.
But if the
"Albatross" could not get out of the cyclone vertically could she not do something else? Could she not gain the center, where it was comparatively calm, and where they would have more control over her?
Quite so, but to do this she would have to break through the circular currents which were sweeping her round with them.
Had she sufficient mechanical power to escape through them?
Suddenly the upper part of the cloud fell in. The vapor condensed in torrents of rain.
It was two o'clock in the morning.
The barometer, oscillating over a range of twelve millimeters, had now fallen to 27.91, and from this something should be taken on account of the height of the aeronef above the level of the sea.
Strange to say, the cyclone was out of the zone to which such storms are generally restricted, such zone being bounded by the thirtieth parallel of north latitude and the twenty-sixth parallel of south latitude.
This may perhaps explain why the eddying storm suddenly turned into a straight one.
But what a hurricane!
The tempest in Connecticut on the 22nd of March, 1882, could only have been compared to it, and the speed of that was more than three hundred miles an hour.
The
"Albatross" had thus to fly before the wind or rather she had to be left to be driven by the current, from which she could neither mount nor escape.
But in following this unchanging trajectory she was bearing due south, towards those polar regions which Robur had endeavored to avoid. And now he was no longer master of her course; she would go where the hurricane took her.
Tom Turner was at the helm, and it required all his skill to keep her straight.