When Benvenuto found how changeable the governor's humour was, he set himself to think over matters seriously. 'For,' he reflected, 'should a fresh fit of anger or suspicion cause him to confine me more strictly, I should feel myself released from my word, and it may be as well to be prepared.'
Accordingly he ordered some new coarse linen sheets to be brought him, but when soiled he did not send them back. When his servants asked for the sheets so as to have them washed he bade them say no more, as he had given them to one of the poor soldiers on guard, who would be sure to get into trouble if the matter were known. By degrees he emptied the straw out of his mattress, burning a little of it at a time in his fireplace, and replacing it with the sheets, which he cut into strips some inches wide. As soon as he thought these strips were long enough for his purpose, he told his servants that he had given all the sheets away, and that in future they had better bring him finer linen, which he would be sure to return.
Now it so happened that every year the governor was subject to a most distressing illness, which, for the time being, entirely deprived him of his reason. When it began to come on, he would talk and chatter incessantly. Each year he had some fresh hallucination, at one time fancying himself an oil-jar, at another a frog, and skipping about like one. Again, another time, he declared he was dead, and wished to be buried; and so, year by year, he was the victim of some new delusion. This year he imagined he was a bat, and as he walked about he uttered little half-smothered cries like a bat, and flapped his hands and moved his body as though about to fly. His faithful old servants and his doctors noticed this, and, thinking change of ideas and variety of conversation might do him good, they frequently fetched Benvenuto to entertain him.
One day the governor asked Benvenuto whether it had ever occurred to him to desire to fly, and; on being answered in the affirmative, he inquired further how he should set about it.
Benvenuto replied that the only flying creature it would be at all possible to imitate artificially was the bat, on which the poor man cried out, 'True, true, that's it, that's the thing.' Then turning round he said, 'Benvenuto, if you had everything you required for it, do you think you could fly?'
'Oh, yes,' said the artist; 'if you will only leave me free to do it, I will engage to make a pair of wings of fine waxed cloth, and to fly from here to Prati with them.'
'And I, too,' exclaimed the governor; 'I could do it too, but the Pope has ordered me to keep you like the apple of his eye, and as I strongly suspect you're a cunning fellow, I shall lock you well up and give you no chance of flying.'
Thereupon, and in spite of all Benvenuto's entreaties and protestations, the governor ordered him to be taken back to prison and more carefully guarded than ever.
Seeing he could not help himself, Cellini exclaimed before the officers and attendants: 'Very well! lock me up and keep me safe, for I give you due warning I mean to escape in spite of everything.'
No sooner was he shut up in his cell than he fell to turning over in his mind how this escape could be made, and began minutely examining his prison, and, after discovering what he thought would be a sure way of getting out, he considered how best he might let himself down from the top of this enormous donjon tower, which went by the name of 'Il Mastio.' He began by measuring the length of the linen strips, which he had cut and joined firmly together so as to form a sort of rope, and he thought there would be enough for his purpose. Next, he armed himself with a pair of pincers which he had taken from one of his guards who was fond of carpentering, and who, amongst his tools, had a particularly large and strong pair of pincers, which appeared so useful to Benvenuto that he abstracted them, and hid them in his mattress.