F Mr. Curtis had been in the car at that moment, especially if he had been in the direct path of the knife, he would have freely acknowledged the fallacy of his theory; for the knife, far from clinging to William's hand, as predicted, sped off like a shot to the ceiling, its velocity being much greater than it would have been if thrown from the surface of the earth with the same force. Bounding back from the cushions, it returned to our hero, who dexterously caught it and put it back in his pocket.

William laughed heartily at this result. "I guess there must be something wrong with Mr. Curtis's reasoning," he said, "though I hardly see where his mistake is. I know that on the earth a ball stuffed with wadding could be thrown only