So strongly was he impressed with this idea, that grasping the iron bar with both hands, he dashed it furiously against the door, making the passage echo with the blows. By degrees, his fears vanished, and hearing nothing, he grew calmer. His spirits revived, and encouraging himself with the idea that the present impediment, though the greatest, was the last, he set himself seriously to consider how it might best be overcome. On reflection, it occurred to him that he might, perhaps, be able to loosen the iron fillet; a notion no sooner conceived than executed. With incredible labour, and by the aid of both spike and nail, he succeeded in getting the point of the bar beneath the fillet. Exerting all his energies, and using the bar as a lever, he forced off the iron band, which was full seven feet high, seven inches wide, and two thick, and which brought with it in its fall the box of the lock and the socket of the bolt, leaving no further hinderance. Overjoyed beyond measure at having vanquished this apparently-insurmountable obstacle, Jack darted through the door. CHAPTER XX. THE LEADS. Ascending a short flight of steps, Jack found at the summit a door, which being bolted in the inside he speedily opened. The fresh air, which blew in his face, greatly revived him. He had now reached what was called the Lower Leads,--a flat, covering a part of the prison contiguous to the gateway, and surrounded on all sides by walls about fourteen feet high. On the north stood the battlements of one of the towers of the gate. On this side a flight of wooden steps, protected by a hand-rail, led to a door opening upon the summit of the prison. This door was crested with spikes, and guarded on the right by a bristling semicircle of spikes. Hastily ascending these steps, Jack found the door, as he anticipated, locked. He could have easily forced it, but preferred a more expeditious mode of reaching the roof which suggested itself to him. Mounting the door he had last opened, he placed his hands on the wall above, and quickly drew himself up. Just as he got on the roof of the prison, St. Sepulchre's clock struck eight. It was instantly answered by the deep note of St. Paul's; and the concert was prolonged by other neighbouring churches. Jack had thus been six hours in accomplishing his arduous task. Though nearly dark, there was still light enough left to enable him to discern surrounding objects. Through the gloom he distinctly perceived the dome of St. Paul's, hanging like a black cloud in the air; and nearer to him he remarked the golden ball on the summit of the College of Physicians, compared by Garth to a “gilded pill.” Other towers and spires--St. Martin's on Ludgate-hill, and Christchurch in Newgate Street, were also distinguishable. As he gazed down into the courts of the prison, he could not help shuddering, lest a false step might precipitate him below.