"I must try to get on their track. I can't afford to lose my money, nor the watch, either." And Robert's face grew serious. The watch was the one his father had given him, and without the money how was he to purchase the map Dick Marden was so anxious to possess? "You'll have to hustle to find them rogues, to my way of thinking," said Lemuel Branley. "Like as not they'll quit Chicago just as soon as possible." Robert stood up. He felt strangely weak and far from able to pursue anybody. "Can you call a policeman?" he asked. "Certainly." Lemuel Branley made off, and while he was gone the boy brushed off his clothing and washed himself. Luckily he had a bit of court-plaster in his pocket, and this he plastered over the cut on forehead, thus doing away with the ragged towel. By the time he had finished he felt a little stronger. Soon the old man came back, followed by a tall, heavy-set officer of the law. "I saw you and one of the men a while ago," said the policeman, after our hero had told his story. "The man didn't impress me very favorably. I rather think I've seen his picture in the rogues' gallery." "Then you would know him again?" "I think I would." "I wish you would try to hunt him up." "I will. Will you go along." Robert was willing, and they left the tenement by the back way, our hero first thanking Lemuel Branley for what he had done. But nothing was to be seen of Andy Cross and Jim Huskin, and in an hour the policeman and the youth gave up the hunt. The officer directed Robert to the nearest station house, and here the particulars of the robbery were taken down. A large book of photographs was placed before Robert, and he soon found Jim Huskin's portrait. "That's the man," he said. "You are certain." "Yes, I would know him out of a thousand." Andy Cross' photograph could not be found, since he had not yet sat for the rogues' gallery, even though he richly deserved it. The officer in charge took down Robert's address, and told our hero if anything was learned he would let the youth know. With this small consolation Robert had to be content. He left the station house much crestfallen. "Everything seems to be going wrong," he mused. "I do hope those rascals are caught, and that very soon." CHAPTER XXI. ROBERT AND THE OLD LUMBERMAN. It must be confessed that Robert was in no humor to hunt up Herman Wenrich. "Even if I find him, what good will it do, if I can't offer him the money for the map?" was his mental comment. Nevertheless, there seemed to be nothing else to do, and so, after a lunch, he started again for No. 238 Grandon Street. He was careful where he went this time, and found the thoroughfare without further difficulty. It was fully eight blocks from the tenement where he had been robbed. The number he was searching for was a block away, and as he walked toward it two men passed him whom he instantly recognized. The men were Jean Le Fevre and Oscar Hammerditch.