"What do you mean?" asked Mr. Bobbsey, wondering why it was that Mr. Mason had so severely shaken the boy who had run away. "Well, I mean that Frank just lost twenty dollars for me," proceeded the lumber man. "Twenty dollars! How was that?" asked Mr. Bobbsey. "I left him in charge of my office, while I was out on some other business," went on the lumber dealer, "and a strange man came in and bought two dollars worth of expensive boards. Frank gave them to him, and the man took them away with him, as they were not very large, or heavy to carry." "Two dollars--I thought you said twenty!" exclaimed Mr. Bobbsey. "So I did. Wait until I tell you all. As I said, Frank sold this strange man two dollars worth of boards. The man gave Frank a twenty dollar bill, and Frank gave him back eighteen dollars in change." "Well, wasn't that right?" asked Mr. Bobbsey, with a smile. "Two dollars from twenty leave eighteen--or it used to when I went to school." "That part is all right," Mr. Mason said, bitterly, "but the fact is that the twenty dollar bill Frank took from the strange man is no good. It is bad money, and no one but a child would take it. It's a bill that was gotten out by the Confederate states during the Civil War, and of course their money isn't any better than waste-paper now. I don't see how Frank was fooled that way. I wouldn't have been if I had been in the office." "Perhaps the boy never saw a Confederate bill before," suggested Mr. Bobbsey. "No matter, he should have known that it wasn't good United States' money!" declared Mr. Mason. "By his carelessness to-day he lost me twenty dollars; the eighteen dollars in my good money that he gave the man in change, and the two dollars worth of boards. And all I have to show for it is that worthless piece of paper!" and Mr. Mason took from his pocket a crumpled bill. Mr. Bobbsey looked at it carefully. "Yes, that's one of the old Confederate States' bills all right," he said, "and it isn't worth anything, except as a curiosity." "It cost me twenty dollars, all right," said Mr. Mason, with a sour look on his face. "I can't see how Frank was so foolish as to be taken in by it." "Well, the poor boy knew no better, and probably he is sorry enough now," said Mr. Bobbsey. "I guess he's sorry enough!" exclaimed Mr. Mason, bitterly. "I gave him a good shaking, as he is too big to whip. I shook him and scolded him." "Well, almost anyone, not very familiar with money, might have made that mistake," spoke Mr. Bobbsey. "This Confederate bill looks very much like some of ours, and a person in a hurry might have been fooled by it." "Oh, nonsense!" broke in Mr. Mason. "There was no excuse for Frank being fooled as he was. I won't listen to any such talk! He lost me twenty dollars and he'll have to make it up to me, somehow."