Hitherto the conversation had thrown no light upon the future movements of Gallia, and Rosette was disposed apparently to evade, or at least to postpone, the subject. When, therefore, Lieutenant Procope was about to press his inquiries in a more categorical form, Servadac, thinking it advisable not prematurely to press the little _savant_ too far, interrupted him by asking the professor how he accounted for the earth having suffered so little from such a formidable concussion.
"I account for it in this way," answered Rosette: "the earth was traveling at the rate of 28,000 leagues an hour, and Gallia at the rate of 57,000 leagues an hour, therefore the result was the same as though a train rushing along at a speed of about 86,000 leagues an hour had suddenly encountered some obstacle.
The nucleus of the comet, being excessively hard, has done exactly what a ball would do fired with that velocity close to a pane of glass.
It has crossed the earth without cracking it.""It is possible you may be right," said Servadac, thoughtfully.
"Right! of course I am right!" replied the snappish professor.
Soon, however, recovering his equanimity, he continued:
"It is fortunate that the earth was only touched obliquely;if the comet had impinged perpendicularly, it must have plowed its way deep below the surface, and the disasters it might have caused are beyond reckoning. Perhaps," he added, with a smile, "even Montmartre might not have survived the calamity.""Sir!" shouted Ben Zoof, quite unable to bear the unprovoked attack.
"Quiet, Ben Zoof!" said Servadac sternly.
Fortunately for the sake of peace, Isaac Hakkabut, who at length was beginning to realize something of the true condition of things, came forward at this moment, and in a voice trembling with eagerness, implored the professor to tell him when they would all be back again upon the earth.
"Are you in a great hurry?" asked the professor coolly.
The Jew was about to speak again, when Captain Servadac interposed:
"Allow me to say that, in somewhat more scientific terms, I was about to ask you the same question. Did I not understand you to say that, as the consequence of the collision, the character of the comet's orbit has been changed?""You did, sir."
"Did you imply that the orbit has ceased to be a parabola?""Just so."
"Is it then an hyperbola? and are we to be carried on far and away into remote distance, and never, never to return?""I did not say an hyperbola."
"And is it not?"
"It is not."
"Then it must be an ellipse?"
"Yes."
"And does its plane coincide with the plane of the earth?""Yes."
"Then it must be a periodic comet?"
"It is."
Servadac involuntarily raised a ringing shout of joy that echoed again along the gallery.
"Yes," continued the professor, "Gallia is a periodic comet, and allowing for the perturbations to which it is liable from the attraction of Mars and Jupiter and Saturn, it will return to the earth again in two years precisely.""You mean that in two years after the first shock, Gallia will meet the earth at the same point as they met before?" said Lieutenant Procope.
"I am afraid so," said Rosette.
"Why afraid?"
"Because we are doing exceedingly well as we are." The professor stamped his foot upon the ground, by way of emphasis, and added, "If I had my will, Gallia should never return to the earth again!"