"EALLY, doctor," said Mr. Curtis, "I don't see how you can reconcile this last statement with what you've already told us. You said just now that as the boy will start a small fraction of a second after the bottom of the car, he cannot catch up with it, and will consequently remain floating in the air."

"In other words," said Dr. Giles, "he will have no weight. If he weighed himself on the spring balance I have placed in the car, he would find that it did not mark a single ounce."

"That I understand. If he floats in the air, it must, of course, be because he has no weight. But now you tell us that near the center of the earth he will have weight. How can you make this tally with what you said before?"

"Remember, James," said Dr. Giles, "that what I