“We couldn’t, Jack,” replied his father. “We were detained in a province which was surrounded by warring Chinese factions, and we couldn’t get out, nor send any word. When we did, your mother and I decided we had had enough of traveling around the world and we started for home. We got here, after sending word to the professor that we were coming, but when we arrived we found that you had run away.” “Did he--did he tell you what for?” “Yes, Jack,” said Professor Klopper, coming forward awkwardly. “And I want to beg your pardon. I--I fear I was a bit hasty.” “Then you know I didn’t steal the cup?” asked Jack rather coldly. “No one stole it. It fell down behind my bureau, and slipped into a hole in the wall where the plaster was off. I found it not long after you had--er--left so unceremoniously, and I wished I could have found you. “Then when I got word from your folks, and I managed to learn that you had joined a circus, I went to the performance, though I do not believe in such frivolous amusements. But I could not find you to tell you the good news. I suppose you were with some other amusement enterprise, Jack?” “No, I saw you,” replied the boy, laughing now, “but I kept out of your way. I was afraid you wanted to arrest me.” “Poor Jack!” whispered his mother. “You had a dreadful time!” “Oh, not so bad,” was the answer. “I earned about three hundred dollars, and I’ve got most of it saved up.” “Three hundred dollars, if put out at six per cent interest, and compounded, will double itself in eleven years, three hundred and twenty-seven days,” remarked the professor thoughtfully. “I would recommend that you do that with your money. In less than twelve years you would have six hundred dollars.” “Not for mine,” said Jack, with a laugh. “I’m going to buy a motorcycle as soon as my leg gets well. That’s as near flying as I care to go for a while.” Jack was taken home as soon as it was practical to move him, and he and the professor became pretty good friends afterward, for it was no small matter for the dictatorial old college teacher to admit, to a mere boy, that such wisdom as could figure out the hardest problem in trigonometry could be wrong when it came to the simple matter of a missing gold cup. Jack got his motorcycle, and a beauty it was, for when he received his money from the circus treasurer he found it was nearer four hundred than three hundred dollars. Part of it he decided to save. “Because you know,” said Jack, “I might some day want to buy a flying machine, and if I put some money out at interest long enough I can get it.”