Chilly fall was upon us, and the sharp, strong wine was served daily instead of on Sunday only. Once again I was inspired.
When my next food was brought, I pleaded for a little vinegar, to medicine a chest ailment. It was brought me in a saucer, and I steeped in it some shavings, whittled from my door. When they seemed sour enough, I placed them at the bottom of my wooden bucket. Into this, day after day, I slowly trickled my ration of wine. It produced a greater quantity of excellent vinegar—at least, for metal-destroying purposes—and after tasting it I felt sure of my acid. Acetic acid, perhaps eight or ten percent at the most.
Painfully scrabbling with a spoon in the trench outside my window, I gained enough clay earth to mix with water and fashion into clumsy basins and jars. These I cautiously hardened in another fire, and employed to hold my supply of vinegar as I increased it, also for other things.
For instance, I constructed a really workable distillery—a narrow-mouthed vase or bottle, suspended above a fire which I fed with chips from the door and furniture, and straw from my bed. As winter came on I heated vinegar in this, and the vapor passed through a hollow reed which I cooled with bits of ice from just outside my barred window. The condensed drops I caught in my cup. They were not pure acetic acid, but a liquid with a high content.
These labors lasted for months. I speak of them briefly, saying nothing of the trial and error, the ludicrous failures and the chance successes that finally made my skill and product adequate. At length, well after Christmas of 1477, I began my attack upon the copper plate that held me from freedom.
At the height of my forehead, and again at the height of my knee, I constructed clay troughs against the metal. These I filled, and kept filled, with the acid. When the action proved slight, I hit upon the device of adding salt, procured by soaking my preserved meat, then evaporating the brine, to the liquid. Thus I got a crude form of hydrochloric acid, which made an appreciable impression. I constantly scraped away the weakened particles of metal, and replenished my supply of salted acid. I wrought for months, and finally was rewarded when the last of the copper along those two narrow lines was eaten away.
The perpendicular acidulation was more difficult, but I managed it by fashioning two clay tubes at the edges of the door, open at the top, rather like the covered tunnels built by tropical ants. These I filled again and again, sometimes pulling them down to pry out the digested copper, then building them afresh for new attacks.
Here, too, I was successful, and one day in February I was able to pry away the whole rectangle of metal within the compass of my four acid-cut channels. There was more wood beyond but, heartened by my triumph, I scraped and chiseled until the door was almost as thin as pasteboard. To the outside view it might appear as strong as ever.
At mid-day of April 16, 1478, I made my bid for escape.
The attendant came to my door, pushed back the slide, and stooped to thrust in my food. I had been waiting for an hour, tense and ready. As I heard him outside, I sprang, bursting through the thin wood like a clown through a paper hoop.
Landing on the monk's unsuspecting back, I whipped an arm beneath his chin, shutting off his breath. He could not cry out, and his struggles availed nothing. I choked him until his limbs grew slack, then stripped off his robe. I donned this and pushed him, senseless, through the smashed door into my cell.
Then I headed down the corridor, cowl over my face, his keys in my hand. I unlocked the door at the end, mounted steps, and came to an upper level. Another corridor I traversed, with measured tread, as though deep in meditation, and none challenged me.
I came into the main hall, saw the doorway to the courtyard. Beyond would be the open, the beach, a boat. I would row away, they would think that a brother was fishing. After that, I would seek land, even among the Turks. But a voice spoke at my elbow.
"You pass me without saluting, brother."
Father Augustino! He had fallen into step beside me. I lifted a hand to my hooded brow, and his single eye fastened upon it.
"How white your flesh, brother. I thought that every monk of our order was tanned brown by God's sunlight. Who are you?"
There was nothing for it but battle. I sprang at him.
Surprise was on my side. I tipped him and fell heavily upon him. But that old priest-soldier, lame and half-blind, was as strong as I, as fierce. I clutched and pressed his throat, but he caught my two little fingers in his hands, bent them painfully backward until I quit the grip.
His thumbs drove into the inner sides of my biceps, torturing nerves between the muscles, and I rolled free of him. We came up to our feet. I struck him heavily on the jaw, and his one eye blinked, but he did not stagger or flinch.
Strongly grappling me around the waist, he rushed me back against a wall, and so held me, despite my pummeling fists in his face, while a dozen monks, swords and axes in hand, rushed in from all directions. In an instant I was secured, and Father Augustino stepped clear of me, dabbing at a trickle of blood from his scarred nose. He panted and grinned, as if he had enjoyed the scrimmage.
"Here's a stout sinner," he growled. "Never did the blessed angel clip Father Jacob more strongly. Thank you for the bout, my son. Put him in my office."
There I was kept under close guard, while the chief stumped away to investigate. He returned after half an hour, and dismissed the guards, but kept his dagger drawn lest I attack him.
"I am amazed at the cunning and courage and labor of your attempt," he began. "How did you manage to cut through the door, copper and all?"
I described my method, and he listened with interest. Several times he asked me to amplify my remarks. At length he smiled.
"You have science and inspiration. How great would be your works if they were turned to honest, godly uses!"
"Being held prisoner, I can turn them only to an effort at escape," I replied.
"Aye, that. Your months of toil, so brilliantly planned and so wearily carried out, came to naught within short minutes. A tragedy." Father Augustino paused and meditated. Then: "My son, what if I gave you freedom?"
"Freedom!" I echoed him hopefully.
"Within limits, of course. Take you from that cell and let you live among us. You could work more science, with true materials to aid you instead of such makeshifts as you fashioned in prison." He gazed at me encouragingly. "Say but the word—swear that you will not seek to flee from this island—"
"I am sorry," I broke in, "but I cannot so doom myself."
"Doom yourself? But you are now held by iron bars and guards."
"And by a false charge, brought against me by a vile rascal," I finished for him. "I thank you, good Father, for your offer, but I live only to escape and to avenge myself. I cannot give you a parole."
He shook his scarred head sadly. Going to the door, he called his monks.
"Hither, some of you," he commanded. "We must find this fellow a straiter prison still."
A new figure pushed through the circle of black gowns, a man in the dress of the world, all particolored hose and plum-purple mantle, with a gay beard and curling locks. Plainly he was a visitor from some Italian city.
"Surely," quoth he, "this is Ser Leo, the artist and scientist, who is held captive by order of Lorenzo the Magnificent."
"Aye, that." Father Augustino nodded. "You know him?"
"I know him," was the reply. "Where doth he go now?"
"To an oubliette, I fear. From there he will need wings to rise."
Two of the armed brothers had torn away my disguising robe, and now marched me down steps, more steps, to a level of natural rock where no light shone save a torch. One of them hoisted a great iron trap-door. I looked into a bottle-shaped pit, at least twelve feet deep.
At that moment the upper levels of the castle wakened to noise—a blown trumpet, a chorus of yells. The two monks turned to look. I tightened my sinews for a desperate fight against them before I might be hurled into that tomblike prison. A flying figure came downstairs.