It had been shown that if such a comet in its flight, instead of falling into the sun, should collide with our planet, the end of the world would be by fire. If it collided with Jupiter it would raise the temperature of that globe to such a point as to restore to it its lost light, and to make it for a time a sun again, so that the earth would be lighted by two suns, Jupiter becoming a sort of minor night-sun, far brighter than the moon, and shining by its own light—of a ruby-red or garnet color, revolving about the earth in twelve years. A nocturnal sun! That is to say, no more real night for the earth. The most classical astronomical treatises had been consulted; chapters on comets written by Newton, Halley, Maupertuis, Lalande, Laplace, Arago, Faye, Newcomb, Holden, Denning, Robert Ball, and their successors, had been re-read. The opinion of Laplace had made the deepest impression and his language had been textually cited: “The earth’s axis and rotary motion changed; the oceans abandoning their old-time beds, to rush toward the new equator; the majority of men and animals overwhelmed by this universal deluge, or destroyed by the violent shock; entire species annihilated; every monument of human industry overthrown; such are the disasters which might result from collision with a comet.” Thus discussion, researches into the past, calculations, conjectures succeeded each other. But that which made the deepest impression on every mind was first that, as proved by observation, the present comet had a nucleus of considerable density, and second, that carbonic-oxide gas was unquestionably the chief chemical constituent. Fear and terror resumed their sway. Nothing else was thought of, or talked about, but the comet. Already inventive minds sought some way, more or less practicable, of evading the danger. Chemists pretended to be able to preserve a part of the oxygen of the atmosphere. Methods were devised for the isolation of this gas from the nitrogen and its storage in immense vessels of glass hermetically sealed. A clever pharmacist asserted that he had condensed it in pastilles, and in a fortnight expended eight millions in advertising. Thus commerce made capital out of everything, even universal death. All hope was not, however, abandoned. People disputed, trembled, grew anxious, shuddered, died even—but hoped on. The latest news was to the effect that the comet, developing, as it approached the thermal and electric influences of the sun, would have at the moment of impact a diameter sixty-five times that of the earth, or 828,000 kilometers. It was in the midst of this state of general anxiety that the session of the Institute, whose utterance was awaited as the last word of an oracle, was opened.