This corridor in which he took regular exercise was the receptacle for much old rubbish; several pieces of rickety furniture had been thrown here, a couple of _cassoni_, or great chests, and a quantity of ancient documents, the records of long forgotten criminal trials. From time to time he turned over this heap of nondescript articles, among which were a warming pan, fire-irons and a pair of old candlesticks, the discarded possessions, no doubt, of some distinguished predecessor to whose comfort and convenience they probably ministered. One other bit of treasure he also found and pounced upon eagerly for future use as a weapon of offence and defence, and yet more as a workman’s tool. This was a straight piece of iron, a foot and a half in length and as thick as a man’s thumb, no doubt a bolt or bar that had been in the lock of a door. Pursuing his investigations, he came upon another article of possible value to him; a piece of black marble six inches long, three inches wide and one inch thick. He promptly took possession of both the bolt and the stone without precisely realising the purpose they would serve, and carried them cautiously to his cell where he hid them carefully away. On subsequent examination he saw plainly that the marble would serve as a whetstone, and that by rubbing it assiduously upon the crowbar, he could manufacture an eight-sided, sharp-edged instrument admirably adapted to help him in breaking prison. Spurred on by his eagerness to provide himself with a weapon so formidable and so unexpectedly put within his reach, Casanova applied himself with unflagging diligence to his task. His difficulties were enormous; he worked in semi-darkness; he could only hold the whetstone in his left hand; he had no oil to assist the trituration; he could only use his own saliva, which left his throat as dry and rough as sandpaper. “I can hardly describe,” he tells us, “the fatigue that possessed me and the acute pain I suffered in completing my laborious undertaking. It was worse torture than any contrived by the most cruel tyrants who have oppressed mankind. My right arm became so stiff that I could barely move it; the palm of my left hand, which held the stone, was one large sore from the blisters that formed and burst as I continued to work on unflinchingly. But I was rewarded after a week of incessant toil by producing an octangular stylet, each side one and one-half inches in length, and the whole tapering into a fine sharp point.” The weapon once manufactured, it was of paramount importance to conceal it, but after long consideration it was lodged safely, and as it proved, successfully, in his armchair underneath the seat.