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!” CHAPTER IV. A REVISED CALENDAR All previous hypotheses, then, were now forgotten in the presence of the one great fact that Gallia was a comet and gravitating through remote solar regions. Captain Servadac became aware that the huge disc that had been looming through the clouds after the shock was the form of the retreating earth, to the proximity of which the one high tide they had experienced was also to be attributed. As to the fulfillment of the professor’s prediction of an ultimate return to the terrestrial sphere, that was a point on which it must be owned that the captain, after the first flush of his excitement was over, was not without many misgivings.