“There’s a professor in town,” explained Joe, “who says it isn’t possible to pitch a curve.”

“Shades of Arthur Cummings and Bobby Mathews!” groaned Dick. “Are there such fossils still left in the world? Hasn’t the old chap ever been to a baseball game?”

“I suppose he has,” smiled Joe. “Anyway, he saw me curve some balls yesterday. He admits that it seems to curve, but tells me that it is only an optical delusion.”

“Listen to that!” exclaimed Dick. “Optical delusion! If that’s so, about ten million fans in this country have trouble with their eyesight and ought to see an oculist. Your professor reminds me of the wise Englishman who wrote a book to prove it impossible for a steamer to cross the Atlantic, and the very first boat that crossed brought his book to this country.”

“Of course,” smiled Joe, “you and I know that he’s wrong. But how are we to prove it to him?”

Dick thought hard for a minute or two. He had had to do all sorts of things in the exercise of his profession, and this had developed his natural ingenuity to the point where he was ready to say with Napoleon that there was no such word as “impossible.”

“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.”

“Bully!” cried Joe. “That will do the trick all right. When do you think you can do it?”

“Oh, almost any time,” answered Dick. “My time is pretty well filled up for today or tomorrow, but if you’ll have the thing rigged up by day after tomorrow, I’ll come over to the gymnasium and take the picture.”