"Your guess about the comet, or whatever it may prove to be, is quite correct. I don't think it is a new one. From what I have seen of it so far, I have every reason to believe that it is Gambert's comet, which was discovered in 1826, and became visible to the naked eye in the autumn of 1833. It then crossed the orbit of the earth one month after the earth had passed the point of intersection. After that, some force divided it, and in '46 and '52 it reappeared as twin comets constantly separating. Now it would seem that the two masses have come together again: and as they are both larger in bulk and greater in density it would appear that, somewhere in the distant fields of Space, they have united with some other and denser body. The result is, that what is practically a new comet, with a much denser nucleus than any so far seen, is approaching our system. Unless a miracle happens, or there is a practically impossible error in my calculations, it will cross the orbit of the earth thirteen months from to-day, at the moment that the earth itself arrives at the point of intersection."
So far Auriole had listened to the stiff scientific phraseology with more interest than alarm; but now she took advantage of a little pause, and said:
"And the consequences, Mr Lennard? I mean the consequences to us as living beings. You may as well tell me everything now that you've gone so far."
"I am going to," he said, stopping for a moment in his walk, "and I am going to tell you something more than that. Granted that what I have said happens, one of two things must follow. If the nucleus of the comet is solid enough to pass through our atmosphere without being dissipated, it will strike the surface with so much force that both it and the earth will probably be transformed into fiery vapour by the conversion of the motion of the two bodies into heat. If not, its contact with the oxygen of the earth's atmosphere will produce an aërial conflagration which, if it does not roast alive every living thing on earth, will convert the oxygen, by combustion, into an irrespirable and poisonous gas, and so kill us by a slower, but no less fatal, process."
"Horrible!" she said, shivering this time. "You speak like a judge pronouncing sentence of death on the whole human race! I suppose there is no possibility of reprieve? Well, go on!"
"Yes," he said, "there is something else. Those are the scientific facts, as far as they go. I am going to tell you the chances now—and something more. There is just one chance—one possible way of averting universal ruin from the earth, and substituting for it nothing more serious than an unparalleled display of celestial fireworks. All that will be necessary is perfect calculation and illimitable expenditure of money."
"Well," she said, "can't you do the calculations, Mr Lennard, and hasn't dad got millions enough? How could he spend them better than in saving the human race from being burnt alive? There isn't anything else, is there?"
"There was something else," he said, stopping in front of her again. She had risen to her feet as she said the last words, and the two stood facing each other in the dim light, while the mechanism of the telescope kept on clicking away in its heedless, mechanical fashion.
"Yes, there was something else, and I may as well tell you after all; for, even if you never see or speak to me again, it won't stop the work being done now. I could have kept this discovery to myself till it would have been too late to do anything: for no other telescope without my help would even find the comet for four months to come, and even now there is hardly a day to be lost if the work is to be done in time. And then—well, I suppose I must have gone mad for the time being, for I thought—you will hardly believe me, I suppose—that I could make you the price of the world's safety.