“I’ll tell you how I think we can fix it!” he exclaimed at length. “We’ll put two bamboo poles about ten feet apart and in a direct line between you and the plate. Then you take your stand in the box exactly in a line with both of them. Between the two poles we’ll stretch a sheet of white paper. You throw the ball so that it goes to the right of the first pole then turns and breaks the paper and comes out to the left of the second pole. That will be proof positive that the ball has described a curve, and no matter how obstinate the professor is he’ll have to admit it.”