The gray-haired man tried to edge his way around the crowd to get close to the two men who seemed to be the principal actors in the adventure. As he did so, the man who had been smoking--making a flying leap over the back platform railing, darted up the street. At the same time the man who had been accused of causing the cigar ashes to scatter over Mr. Post's vest, slipped from the steps and made a hurried run for the sidewalk. "After him, some one!" cried the gray-haired man. "I'll get the other chap. He's the main one. The other is only a confederate," and he was off in a trice. The car did not stop, though several men, understanding what it was all about, called the conductor. "Can't delay," replied the knight of the bell-rope. "If you want to see the fun, get off. Pickpockets are too common to stop the car for." "Well, I reckon I blocked his game that time," said Mr. Post, as he looked at the diamond which had lately adorned his shirt front. "I don't read the newspapers for nothing, and they'll find Josh Post is hard to beat." "What did he do to you?" asked some of the passengers. "Tried to frisk me out of my sparkler," replied the miner. "It's a new way of working an old trick, but I read about it in a New York paper last week." "How did he do it?" asked Jack. "There were two of 'em," Mr. Post went on. "That fellow had his cigar, with lots of ashes on it, already for me. Then the other fellow bunked into him, and he flicked the ashes on me. Of course he made a play to pretend it was the other fellow's fault, and he started to brush me off. But while he was doing it with his big handkerchief, he was taking out my diamond. I caught him just in time." "But who was the man who chased him, and gave you back your diamond?" asked Jack. "Detective, I reckon," replied the miner. "They're often riding on the cars on the lookout for just such things as that." "That's who he was," the conductor explained. "There's been a lot of pickpockets here lately, and the detectives are riding back and forth all day. Hope he catches that fellow." "Don't worry me any," said Mr. Post "I've got my diamond back," and he placed the sparkling stone in his pocket for safe keeping. Whether the detective ever caught the slick thief the boys never learned. They made the trip out to Lake Erie, and when they had looked at the big body of water and taken a short trip in a launch they returned to the station to find it was nearly the hour set for the departure of their train. "Things seem to be coming our way," remarked Mr. Post after they had been riding half an hour. "We've had lively times since we met, boys. But I'll have to leave you in Chicago." "Perhaps we'll see you again," said Nat. "Have you ever been out west?" "In my younger days," replied the miner. "I had a friend once named Travers--um--no--that wasn't exactly his name either. Travis-- Trellis--Tennis--" "Tevis!" exclaimed Jack, struck by a sudden inspiration.