Uncle and Aunt walked on over the bridge but John and Fanny stopped to hear the music made by a cornet band of girls on one of the excursion steamers. The tall masts of a lumber boat could be seen coming rapidly toward them in tow with an insignificant little steamer. There was a jing-aling two or three times of a bell hid somewhere in the framework of the bridge, teamsters and people were hurrying across, and all at once the bridge began to move. Johnny saw some people remaining on the bridge and catching Fanny by the hand he cried, "Here let's take a ride" and in a moment they were swayed past the street and out over the stream. Over at the other end they saw Uncle and Aunt holding desperately on to the railing. They had not been able to get over when the bridge moved away. Presently the boats were past and the bridge rapidly swung into place. Down the street half a block Johnny saw some steam issuing from the middle of the street. Instantly the idea of a volcanic eruption in the middle of Chicago possessed his mind. He called Fanny's attention to it and their curiosity was greatly excited. They had heard that Chicago was a very wicked place and their preacher had once remarked that he would not be surprised at any time to hear of an upheaval by the Lord sending the city over into the lake. In considerable dread lest the overthrow was about to take place, they walked towards the place along the sidewalk, as the famous Harry walked up to the guidepost at the country crossroads on that cloudy night so long ago. But they were greatly reassured when they found the people about them were so indifferent and they were chagrined to learn that they were again deceived. It was no volcano, there would be no terrible cataclysm, it was only an inoffensive man-hole to the sewers, into which the waste steam of one of the factories near by was escaping. Meanwhile, Uncle and Aunt had stepped off of the bridge and were intensely bewildered all at once to find that the excursion steamer and the houses next to it had all apparently jumped across the river to their side. "Did we come acrost that bridge?" Uncle asked. "I know we never." "How did we git acrost without coming acrost?" "I can't see how anybody could come across without comin' across, and I know we never," said Aunt. "Well, ef we hain't acrost, then the houses are acrost, and it is more natural fer us ter be crazy than for the houses to get acrost." "Ask the policeman." Uncle went up to the policeman and said: "Say, Mister, we want to know if you will be so kind as to tell us ef we are acrost or not acrost." "Do you mean on the north side or the south side?" "No; I mean on this side or the other side." "Well, which side did you come from?" "I thought I came from the other side," said Uncle, "but it seems now as if I came from this side and didn't go over to the other side at all." "Where have you been?" asked the policeman, making a mighty effort to untangle himself.