Page:Clement Fezandié - Through the Earth.djvu/34

14 succeeded in finding what I sought. I am now able to produce a temperature of about 425° F. below zero, and you will readily admit that a cold of this intensity can be made to offset any heat that I may meet with in my undertaking."

"But how do you manage to secure so great a degree of cold?" asked Mr. Curtis, somewhat skeptically.

"The details of the operation," said Dr. Giles, "would naturally be too complex to explain offhand, but the general principle on which I work is quite simple. To begin with, I suppose you are aware that, properly speaking, there is no such thing as cold. We say that ice is cold because it has considerably less heat than the human body. But ice nevertheless does possess heat, and quite a goodly amount of it, too. The only bodies which possess no heat whatever are those which are at a temperature of about 459° F. below zero. This is, to the best of our knowledge, the point of absolute cold, that is to say, the point at which a body will retain absolutely no heat at all. By no process that we know of can such absolute cold be produced,—although, as I have said, I have succeeded in coming very near to it."

"But how do you manage to obtain such a low temperature?" persisted Mr. Curtis.