Babbage pursed his lips and pondered. "We’ve thought of everything from window to ground," he said presently. "The only thing we haven’t thought of is the roof, and we want to go down, not up—leastways, not yet." "I don’t know. What about the chimney?" "No good, sir. Haven’t I seed the sergeant of the guard poke his nose up every day to see if the bars are safe? They’re just fixed so that no nat’ral man’s head could pass between. Must ha’ bin done a purpose." "Does the sergeant examine them carefully?" "No, sir; he just stoops down, and cocks his head around, and gives a squint up, and many’s the time I’d ha’ liked to take advantage of the sitivation to kick him, only I thought I’d better not. ’Kicks is poor tricks,’ too, as brother Sol used to say." "Well, I’ll come into your room to-night, and have a look at them. Luckily the chimney is on the same side as the door; the sentry won’t see me. We might be able to loosen those bars and clear the chimney." "And what then, sir?" "I’d climb the roof and take a look round. Can’t say more at present." "Very good, sir." In the small hours Jack crept quietly into the larger room and got into the chimney unobserved. The bars were just above his head, and he very soon decided that with a sufficiently hard implement he could loosen the mortar about their ends. That was the doubtful matter. The knives supplied to a few of the prisoners who were given meat for their dinner were removed by the jailers after the meal, and all weapons had of course been taken from the men before they were brought into the room. But next morning Jack managed to force a long rusty nail out of one of the planks of the floor of his room; it seemed to him stout and strong enough for his purpose. It was necessary to take the rest of the prisoners into his confidence. He got Babbage to tell them what he had in view, and as they were all Englishmen, with just as keen a longing for liberty as himself, there was no fear of their betraying him. As soon as the jailers had distributed the morning rations he slipped into the chimney. Half a dozen of the men, gathered as if casually near the fireplace, screened him from any one who might suddenly enter the room. He began to scrape away the mortar at one end of each of the bars, working as quickly as he could. Turley swept up with his hand the flakes of mortar that fell to the floor. By the evening Jack had worked so well that one bar was loosened sufficiently to be bent down when the time came. Then he got some of the men to tear off scraps of their woolen shirts, and with these he filled up the holes, so that even if the bar was tested by the sergeant there was a good chance that it would hold well enough to prevent discovery. The scraping occupied him for two more days—one bar a day. By the time he had finished he found that the nail which had served him so well was worn to within half an inch of the head.