Again did Robur approach his prisoners, who affected to be in no way surprised at what they saw, of what had succeeded in spite of them. Evidently beneath the cranium of these two Anglo-Saxon heads there was a thick crust of obstinacy, which would not be easy to remove.
On his part, Robur did not seem to notice anything particular, and coolly continued the conversation which he had begun two hours before.
“Gentlemen,” said he, “you ask yourselves doubtless if this apparatus, so marvelously adapted for aerial locomotion, is susceptible of receiving greater speed. It is not worth while to conquer space if we cannot devour it. I wanted the air to be a solid support to me, and it is. I saw that to struggle against the wind I must be stronger than the wind, and I am. I had no need of sails to drive me, nor oars nor wheels to push me, nor rails to give me a faster road. Air is what I wanted, that was all. Air surrounds me as it surrounds the submarine boat, and in it my propellers act like the screws of a steamer. That is how I solved the problem of aviation. That is what a balloon will never do, nor will any machine that is lighter than air.”
Silence, absolute, on the part of the colleagues, which did not for a moment disconcert the engineer. He contented himself with a half-smile, and continued in his interrogative style, “Perhaps you ask if to this power of the Albatross to move horizontally there is added an equal power of vertical movement—in a word, if, when, we visit the higher zones of the atmosphere, we can compete with an aerostat? Well, I should not advise you to enter the Go-Ahead against her!”
The two colleagues shrugged their shoulders. That was probably what the engineer was waiting for.
Robur made a sign. The propelling screws immediately stopped, and after running for a mile the Albatross pulled up motionless.
At a second gesture from Robur the suspensory helices revolved at a speed that can only be compared to that of a siren in acoustical experiments. Their f‑r‑r‑r‑r rose nearly an octave in the scale of sound, diminishing gradually in intensity as the air became more rarified, and the machine rose vertically, like a lark singing his song in space.
“Master! Master!” shouted Frycollin. “See that it doesn’t break!”
A smile of disdain was Robur’s only reply. In a few minutes the Albatross had attained the height of 8,700 feet, and extended the range of vision by seventy miles, the barometer having fallen 480 millimeters.
Then the Albatross descended. The diminution of the pressure in high altitudes leads to the diminution of oxygen in the air, and consequently in the blood. This has been the cause of several serious accidents which have happened to aeronauts, and Robur saw no reason to run any risk.
The Albatross thus returned to the height she seemed to prefer, and her propellers beginning again, drove her off to the southwest.
“Now, sirs, if that is what you wanted you can reply.” Then, leaning over the rail, he remained absorbed in contemplation.
When he raised his head the president and secretary of the Weldon Institute stood by his side.
“Engineer Robur,” said Uncle Prudent, in vain endeavoring to control himself, “we have nothing to ask about what you seem to believe, but we wish to ask you a question which we think you would do well to answer.”
“Speak.”
“By what right did you attack us in Philadelphia in Fairmount Park? By what right did you shut us up in that prison? By what right have you brought us against our will on board this flying machine?”
“And by what right, Messieurs Balloonists, did you insult and threaten me in your club in such a way that I am astonished I came out of it alive?”
“To ask is not to answer,” said Phil Evans, “and I repeat, by what right?”
“Do you wish to know?”
“If you please.”
“Well, by the right of the strongest!”
“That is cynical.”
“But it is true.”
“And for how long, citizen engineer,” asked Uncle Prudent, who was nearly exploding, “for how long do you intend to exercise that right?”
“How can you?” said Robur, ironically, “how can you ask me such a question when you have only to cast down your eyes to enjoy a spectacle unparalleled in the world?”
The Albatross was then sweeping across the immense expanse of Lake Ontario. She had just crossed the country so poetically described by Cooper. Then she followed the southern shore and headed for the celebrated river which pours into it the waters of Lake Erie, breaking them to powder in its cataracts.
In an instant a majestic sound, a roar as of the tempest, mounted towards them; and, as if a humid fog had been projected into the air, the atmosphere sensibly freshened.
Below were the liquid masses. They seemed like an enormous flowing sheet of crystal amid a thousand rainbows due to refraction as it decomposed the solar rays. The sight was sublime.
Before the falls a footbridge, stretching like a thread, united one bank to the other. Three miles below was a suspension-bridge, across which a train was crawling from the Canadian to the American bank.
“The falls of Niagara!” exclaimed Phil Evans. And as the exclamation escaped him, Uncle Prudent was doing all he could to admire nothing of these wonders.
A minute afterwards the Albatross had crossed the river which separates the United States from Canada, and was flying over the vast territories of the West.
IX
Across the Prairie
In one of the cabins of the after-house Uncle Prudent and Phil Evans had found two excellent berths, with clean linen, change of clothes, and traveling-cloaks
