rate. But this scarcely appears possible. You might as well claim that, because the temperature becomes colder the higher we ascend on a mountain, if we were to continue forever in a vertical line the temperature would keep on decreasing at the same rate."
"Well, would n't it?"
"Most certainly not. We, of course, know very little about the matter, but this we do know, that there is a point of absolute cold, which is supposed to be at 459° F. below zero. A body at this temperature would have absolutely no heat left in it. Our scientists may very well be mistaken as to the exact figure, but, at any rate, we know that there is some point beyond which the cold cannot continue to increase as we ascend in the air. Hence those who argue that because the cold becomes greater when we climb a mountain, it would continue increasing at the same rate if we ascended into the heavens, would be altogether mistaken. Similarly, those who claim that because the temperature becomes higher as we descend in mines, the heat must be inconceivable after we have gone a few miles, have no logical basis for their statement."
"But does not the existence of volcanoes prove
