In the snug little office in Arizona we find them; Charley with his feet poised on the desk and Williams precise and punctilious, true to his training, defending the exactness of his philosophy. It was the cool of the evening; the sun was just mellowing the heat of the desert. Through the open door and windows a cool wind was blowing. Charley was smoking; the same old pipe had been the bane of Williams’s life at college. “Then we know?” he was asking. “Yes,” spoke the professor, “what we know, Charley, we know; though of course it is not much. It is very hard, nay impossible, to deny figures. We have not only the proofs of geology but of astronomical calculation, we have facts and figures plus our sidereal relations all about us. “The world must come to an end. It is a hard thing to say it, but it is a fact of science. Slowly, inevitably, ruthlessly, the end will come. A mere question of arithmetic.” Huyck nodded. It was his special function in life to differ with his former roommate. He had come down from his own mountain in Colorado just for the delight of difference. “I see. Your old calculations of tidal retardation. Or if that doesn’t work the loss of oxygen and the water.” “Either one or the other; a matter of figures; the earth is being drawn every day by the sun: its rotation is slowing up; when the time comes it will act to the sun in exactly the same manner as the moon acts to the earth to-day.” “I understand. It will be a case of eternal night for one side of the earth, and eternal day for the other. A case of burn up or freeze up.” “Exactly. Of if it doesn’t reach to that, the water gas will gradually lose out into sidereal space and we will go to desert. Merely a question of the old dynamical theory of gases; of the molecules to be in motion, to be forever colliding and shooting out into variance. “Each minute, each hour, each day we are losing part of our atmospheric envelope. In course of time it will all be gone; when it is we shall be all desert. For instance, take a look outside. This is Arizona. Once it was the bottom of a deep blue sea. Why deny when we can already behold the beginning.” The other laughed. “Pretty good mathematics at that, professor. Only—” “Only?” “That it is merely mathematics.” “Merely mathematics?” The professor frowned slightly. “Mathematics do not lie, Charlie, you cannot get away from them. What sort of fanciful argument are you bringing up now?” “Simply this,” returned the other, “that you depend too much on figures. They are material and in the nature of things can only be employed in a calculation of what may happen in the future. You must have premises to stand on, facts. Your figures are rigid: they have no elasticity; unless your foundations are permanent and faultless your deductions will lead you only into error.” “Granted; just the point: we know where we stand. Wherein are we in error?”