"But his friends began to prate to him about the shameful way he had been jilted by Cecilia, and, by constantly reiterating the same thing, they at last succeeded in persuading him that he was an ill-used man. His self-esteem being roused by this silly chatter, he began to affect a ridiculous desolation, and to perpetrate all manner of outrageous extravagances."
"Bad friends," remarked Willis, "are like sinking ships; they drag you down to their own level."
"The first absurd thing he did was to purchase a yacht, and when a storm arose that forced the hardy fishermen to take shelter in port, he went out to sea, and it is quite a miracle that he escaped drowning. Then, if there were a doubtful scheme afloat, he was sure to take shares in it. Nothing delighted him more than to go up in a balloon; he would have gladly swung himself on the car outside if the proprietor had allowed him."
"I have often seen balloons in the air," remarked Willis, "but I could never make out their dead reckoning."
"A balloon," replied Ernest, "is nothing more than an artificial cloud, and its power of ascension depends upon the volume of air it displaces.
"Very good, Master Ernest, so far as the balloon itself is concerned; but then there is the weight of the car, passengers, provisions, and apparatus to account for."
"Hydrogen gas, used in the inflation of balloons, is forty times lighter than air. If a balloon is made large enough, the weight of the car and all that it contains, added to that of the gas, will fall considerably short of the weight of the air displaced by the machine."
"I suppose it rises in the air just as an empty bottle well corked rises in the water?"
"Very nearly. Air is lighter than water; consequently, any vessel filled with the one will rise to the surface of the other. So in the case of balloons. The gas, in the first place, must be inclosed in an envelope through which it cannot escape. Silk prepared with India-rubber is the material usually employed. As the balloon rises, the gas in the interior distends, because the air becomes lighter the less it is condensed by its superincumbent masses; hence it is requisite to leave a margin for this increase in the volume of the gas, otherwise the balloon would burst in the air."
"If a balloon were allowed to ascend without hindrance where would it stop?"