But trying is one thing, and finding out another. Having no means of comparing themselves with external objects, they could not possibly tell whether they were moving, or at an absolute stand-still. Though our Earth is whirling us continually around the Sun at the tremendous speed of 500 miles a minute, its inhabitants are totally unconscious of the slightest motion. It was the same with our travellers. Through their own personal consciousness they could tell absolutely nothing. Were they shooting through space like a meteor? They could not tell. Had they fallen back and buried themselves deep in the sandy soil of Florida, or, still more likely, hundreds of fathoms deep beneath the waters of the Gulf of Mexico? They could not form the slightest idea.

Listening evidently could do no good. The profound silence proved nothing. The padded walls of the Projectile were too thick to admit any sound whether of wind, water, or human beings. Barbican, however, was soon struck forcibly by one circumstance. He felt himself to be very uncomfortably warm, and his friend's faces looked very hot and flushed. Hastily removing the cover that protected the thermometer, he closely inspected it, and in an instant uttered a joyous exclamation.

"Hurrah!" he cried. "We're moving! There's no mistake about it. The thermometer marks 113 degrees Fahrenheit. Such a stifling heat could not come from the gas. It comes from the exterior walls of our projectile, which atmospheric friction must have made almost red hot. But this heat must soon diminish, because we are already far beyond the regions of the atmosphere, so that instead of smothering we shall be shortly in danger of freezing."

"What?" asked Ardan, much bewildered. "We are already far beyond the limits of the terrestrial atmosphere! Why do you think so?"

M'Nicholl was still too much flustered to venture a word.

"If you want me to answer your question satisfactorily, my dear Ardan," replied Barbican, with a quiet smile, "you will have the kindness to put your questions in English."

"What do you mean, Barbican!" asked Ardan, hardly believing his ears.

"Hurrah!" cried M'Nicholl, in the tone of a man who has suddenly made a welcome but most unexpected discovery.

"I don't know exactly how it is with the Captain," continued Barbican, with the utmost tranquillity, "but for my part the study of the languages never was my strong point, and though I always admired the French, and even understood it pretty well, I never could converse in it without giving myself more trouble than I always find it convenient to assume."

"You don't mean to say that I have been talking French to you all this time!" cried Ardan, horror-stricken.