In vain the steam whistle screamed its fanfares on to the assembly.
Philadelphia might well think that a fire was devouring one of its quarters and that all the waters of the Schuyllkill could not put it out.
Suddenly there was a recoil in the tumult.
Robur had put his hands into his pockets and now held them out at the front ranks of the infuriated mob.
In each hand was one of those American institutions known as revolvers which the mere pressure of the fingers is enough to fire -- pocket mitrailleuses in fact.
And taking advantage not only of the recoil of his assailants but also of the silence which accompanied it.
"Decidedly," said he, "it was not Amerigo that discovered the New World, it was Cabot!
You are not Americans, citizen balloonists!
You are only Cabo-"
Four or five shots cracked out, fired into space.
They hurt nobody.
Amid the smoke, the engineer vanished; and when it had thinned away there was no trace of him.
Robur the Conqueror had flown, as if some apparatus of aviation had borne him into the air.
Chapter V
ANOTHER DISAPPEARANCE _____
This was not the first occasion on which, at the end of their stormy discussions, the members of the Weldon Institute had filled Walnut Street and its neighborhood with their tumult.
Several times had the inhabitants complained of the noisy way in which the proceedings ended, and more than once had the policemen had to interfere to clear the thoroughfare for the passersby, who for the most part were supremely indifferent on the question of aerial navigation.
But never before had the tumult attained such proportions, never had the complaints been better founded, never had the intervention of the police been more necessary.
But there was some excuse for the members of the Weldon Institute.
They had been attacked in their own house. To these enthusiasts for "lighter than air" a no less enthusiast for "heavier than air" had said things absolutely abhorrent.
And at the moment they were about to treat him as he deserved, he had disappeared.
So they cried aloud for vengeance.
To leave such insults unpunished was impossible to all with American blood in their veins.
Had not the sons of Amerigo been called the sons of Cabot?
Was not that an insult as unpardonable as it happened to be just--historically?
The members of the club in several groups rushed down Walnut Street, then into the adjoining streets, and then all over the neighborhood.
They woke up the householders; they compelled them to search their houses, prepared to indemnify them later on for the outrage on their privacy.
Vain were all their trouble and searching.
Robur was nowhere to be found; there was no trace of him.
He might have gone off in the "Go-Ahead," the balloon of the Institute, for all they could tell.
After an hour's hunt the members had to give in and separate, not before they had agreed to extend their search over the whole territory of the twin Americas that form the new continent.
By eleven o'clock quiet had been restored in the neighborhood of Walnut Street.
Philadelphia was able to sink again into that sound sleep which is the privilege of non-manufacturing towns.
The different members of the club parted to seek their respective houses.
To mention the most distinguished amongst them, William T.
Forbes sought his large sugar establishment, where Miss Doll and Miss Mat had prepared for him his evening tea, sweetened with his own glucose.
Truck Milnor took the road to his factory in the distant suburb, where the engines worked day and night.
Treasurer Jim Chip, publicly accused of possessing an alimentary canal twelve, inches longer than that of other men, returned to the vegetable soup that was waiting for him.
Two of the most important balloonists--two only--did not seem to think of returning so soon to their domicile.
They availed themselves of the opportunity to discuss the question with more than usual acrimony.
These were the irreconcilables, Uncle Prudent and Phil Evans, the president and secretary of the Weldon Institute.
At the door of the club the valet Frycollin waited for Uncle Prudent, his master, and at last he went after him, though he cared but little for the subject which had set the two colleagues at loggerheads.
It is only an euphemism' that the verb "discuss" can be used to express the way in which the duet between the president and secretary was being performed.
As a matter of fact they were in full wrangle with an energy born of their old rivalry.
"No, Sir, no," said Phil Evans. "If I had had the honor of being president of the Weldon Institute, there never, no, never, would have been such a scandal."
"And what would you have done, if you had had the honor?" demanded Uncle Prudent.
"I would have stopped the insulter before he had opened his mouth."
"It seems to me it would have been impossible to stop him until he had opened his mouth," replied Uncle Prudent.
"Not in America, Sir; not in America."
And exchanging such observations, increasing in bitterness as they went, they walked on through the streets farther and farther from their homes, until they reached a part of the city whence they had to go a long way round to get back.