really all the same thing under different forms, and that one can be readily converted into the other? Every day we change heat into force, light, or electricity, and vice versa, so that what I propose to do here is merely what the world has been doing for many years."
"Well, go on," said Mr. Curtis.
"There is nothing further to say, but simply this, that, in casting the tube, I have so prepared both the outer and the inner surface that any heat above 70° F. will at once be changed into electricity by a secret process of my own devising. This electricity instantaneously passes to my office along the conductors mentioned. As you are aware, electrical energy travels so fast that it can go eight times around the earth in a single second; you will therefore see that, so long as I can use up this energy as fast as it reaches me, the tube cannot acquire a temperature much above 70° F. As soon as the heat becomes greater than this, the excess is at once converted into electrical energy and instantaneously passes to my office."
"But how do you get rid of all this electricity that accumulates in your office?" queried Mr. Curtis.
"I sell it."
