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. After leaving the desk, amid a volley of revolver shots, he had disappeared, and in spite of every endeavor, no trace could be found of him. Assuredly here was enough to exercise every tongue and excite every imagination. But by how much was this excitement increased when in the evening of the 13th of June it was found that neither the president nor secretary of the Weldon Institute had returned to their homes! Was it by chance only that they were absent? No, or at least there was nothing to lead people to think so. It had even been agreed that in the morning they would be back at the club, one as president, the other as secretary, to take their places during a discussion on the events of the preceding evening. And not only was there the complete disappearance of these two considerable personages in the state of Pennsylvania, but there was no news of the valet Frycollin. He was as undiscoverable as his master. Never had a Negro since Toussaint L’Ouverture, Soulouque, or Dessaline had so much talked about him. The next day there was no news. Neither the colleagues nor Frycollin had been found. The anxiety became serious. Agitation commenced. A numerous crowd besieged the post and telegraph offices in case any news should be received. There was no news. And they had been seen coming out of the Weldon Institute loudly talking together, and with Frycollin in attendance, go down Walnut Street towards Fairmount Park! Jem Chip, the vegetarian, had even shaken hands with the president and left him with “Tomorrow!” And William T. Forbes, the manufacturer of sugar from rags, had received a cordial shake from Phil Evans who had said to him twice, “Au revoir! Au revoir!” Miss Doll and Miss Mat Forbes, so attached to Uncle Prudent by the bonds of purest friendship, could not get over the disappearance, and in order to obtain news of the absent, talked even more than they were accustomed to.