find it nearly as hard to ran about, and would hurt herself almost as much if she tumbled down, as she does here."
"Well, I declare! That passes my comprehension!" exclaimed Mr. Curtis. "Time and again have I heard it said that at the center of the earth there would be no attraction of gravitation whatever. Consequently I can scarcely credit what you say."
"Understand me," said Dr. Giles. "What I say is that if a body were standing still at the center of the earth it would indeed weigh nothing. But the objects that will be in my car will, I am convinced, have a certain amount of weight at the moment when they reach the center of the earth."
"Ah, I see; you mean to say that the car will be moving so fast that the bodies will not remain a single second at the very center of the earth, and consequently the passengers will not have time to feel the effects of the loss of weight."
"No," said Dr. Giles, "that is not where the trouble lies. The difficulty is that I shall not be able to produce a perfect vacuum in the tube. Even with all the appliances I have devised for removing the air, there will still be a small amount left—enough to keep the car from coming
