Casanova philosophically tells us that the man possessed of one fixed aspiration will generally compass his end, however highly placed; he will achieve rank and fortune and a great position, if he keeps his mind steadily to his one idea. With him this idea was to escape, and he pondered over it incessantly, puzzling over the means by which he could attempt it. Certainly they did not lie ready to his hand. He saw a way, feasible enough, of getting out of his cell, but could not imagine how to procure the necessary tools. He was securely lodged, alone and apart, absolutely cut off from outside and his fellow creatures, save his warder, who could only help him by braving terrible penalties. Armed sentries were posted in the corridors and at his door, whose vigilance he could hardly hope to elude and who would easily have overpowered him if he attacked them. Yet the way of escape was possible through the floor of his chamber which, being perfectly familiar with the geography of the palace, he knew to be just above the hall of the inquisitors where they met for business in the evening after the Council of the Ten, of which they were members, had concluded their proceedings. If he could but break through the floor and lower himself into the great hall below when it was unoccupied, he might walk off by the grand staircase, that of the “Giants,” which visitors to Venice may still admire. There was no difficulty about the exit, but how was he to reach it? We shall see presently how the pressure of his needs stimulated his active brain and sharpened his ingenious wits.