by Giulio Leoni
Bonatti nodded slowly. ‘Frederick was a mad blasphemer. A champion of the impossible. If light had a motion, it would continue for ever, heading towards a horrendous, infinite void. All certainty, all stability of the creation would collapse. All this had to be stopped. It was written in the stars that I was the one to do it.’
‘You are the madman. The measurement of the created universe would have been the supreme work of human genius, a song of praise to God.’
The astrologer had leaped to his feet with unexpected agility, moving towards him. Dante took a step back. But Bonatti did not seem to want to attack him. He was staring at something behind him. The poet instinctively turned round: the double wound on the bodies of the murdered men returned to his mind and he feared that the second murderous hand was hidden behind him.
But there was no one there. Bonatti was lost in contemplation of a group of stars low on the horizon. ‘Scorpio is rising … So it was written, so it will happen,’ he murmured, closing his eyes, his voice suddenly distant. ‘All the wickedness of the Moors and their necromancy can do nothing against the admirable architecture of Creation, motionless light and its stable confines.’
‘It was not the Moors who sought the truth, but the best minds of our century, of our race, of our faith, of our tongue! And many of them have been extinguished by you!’ Dante replied angrily. ‘It was not your certainty, but your power that led you to kill.’
The old man clenched his fists in front of him, as his mouth struggled to reply.
‘How old are you, Messer Bonatti?’ the prior pressed him. ‘Haven’t you lived through most of this century? And after so many years, in which you have seen and known everything, you wanted to deprive yourself of the greatest experiment of all? I challenge you to this test: in the Baptistery, with its perfect geometry. That which was not possible in Puglia will happen here,’ he continued resolutely, pointing his hand towards the marble mass behind them.
‘Like Saint Thomas you want to seek the truth in blood,’ the astrologer replied. ‘That blood will extinguish the infernal fire of your pride, it will temper your arrogance. I do not fear your challenge. So enter the temple, if you dare to profane it with your confused science.’
‘By the northern door. In the Baptistery they are finishing off the big mosaic in the dome, and it is left open to allow the workmen in and out.’
Behind them the two monks had been watching in silence, their puzzled expressions hidden by the hoods over their faces. The group slipped along the side of the Baptistery, passing into the narrow alley that separated it from the nearest buildings, which leaned against its perfect form like ragged beggars.
‘Push the cart in and then leave us. I will deal with the transport of the corpse,’ the poet commanded. ‘Return to the battleground and bury the remains of the Virgin of Antioch, beyond San Lorenzo.’ His voice was tinged with grief. ‘And respect them, because her end was more atrocious than her guilt. As for what you have seen, forget it all.’
Bonatti had remained apart. As soon as they were alone, his hand trembling with excitement, he lifted aside the heavy length of felt that protected one of the slabs, then brushed the icy surface with his fingers, like a blind man using the sense of touch to seek confirmation of his imaginings.
By the faint moonlight that entered through the windows, Dante found a candelabra and with a few strokes of his tinder-box lit the candle stumps. Then he turned towards Guido Bonatti, who had sat down on the edge of the baptismal font. He looked exhausted, covered with sweat, as if his great age had suddenly revealed itself. He struggled to breathe the thick, heavy air, staring at Arrigo’s lifeless eyes.
The poet pulled Bigarelli’s diagram from his bag. But the astrologer, having sprung back into life with unexpected force, had already begun striding across the Baptistery floor, as if that same diagram had been imprinted on his mind in symbols of fire.
‘A thousand times I have read that diabolical plan, a thousand days I have woken with its image before my eyes, a thousand nights I have descended into the darkness bringing it with me. You don’t need that filthy scrap of paper. Put the first mirror there!’
In a corner Arrigo’s body, wrapped in its shroud, seemed to be watching their movements. The edge of the cloth had slipped down, revealing his face. It was only right that he should be there, Dante thought. Less than two hours had passed since his death, and his soul was still wandering on the borders of the realm of shadows. He could still see.
One by one the eight slabs were placed against each of the walls. Bonatti followed the perimeter of the construction, outlining the angles from memory as if marking on the stone the trace of one last, extraordinary horoscope. Dante followed him, checking with a candle that each mirror caught the image of its companion on the right and reflected it precisely to the one on the left in a circle of repeated images.
‘Do you really think there’s any point to all this?’ the astrologer said, arms pressed to his chest as he waited for the last slab to be put in place.
‘Yes. I’m sure of it,’ the poet replied, checking in the candle-light the point where Elias’ lamp was to be placed, facing towards the first mirror.
He cast one last glance at Arrigo. His hands trembled with excitement as he opened the little door of the lamp. Then, with a more resolute gesture, he brought the vivid flame to the little bottle.
The white powder caught fire with an incandescent flash. Concentrated by the brass shield, the ray seemed to bounce against the glass surface. All around them a phantasmagoria of light lit up along the walls of the Baptistery like a crown of flames. The splendour of Elias’ light set the dust aflame, transformed by the rays into a galaxy of stars. Vague in the shadows above them still hung the face of Christ the Lord surrounded by the angelic hosts, mute witnesses to the events below.
‘There they are!’ cried Dante to his adversary, showing the strips of light reflected from one glass surface to another. ‘There are the rays of which al-Kindi speaks. The light has run from one mirror to the next!’
‘You are wrong! The circle of flashes all around us appeared in unison, and not by degrees. It proves not motion, but the sempiternal motionlessness of light. Omnipresent and constant as its creator.’
The prior shook his head violently and freed the spring of the machine. The toothed axle began to rotate, slowly at first, then faster and faster. He brought his eye to the slit in the side opposite the one holding the lamp. The halo of light shone all around, but the thickest darkness lay within the opening.
Bonatti too had drawn close to the observation point, and stepped back with a mocking expression. ‘Behold the darkness that punishes your ignorance, Messer Alighieri!’ he spat disdainfully. ‘I have been familiar with the nature of this devilry since Michael Scotus demonstrated its working. If the light passed through the teeth of the two opposing wheels, that would be proof of its motion. But it was merely the illusion of his hazy mind. None of this will happen.’
Dante bit his lips uncertainly. The growing roar of the gear-wheels filled the air as the thrust of the spring increased the speed of the rotation. The fins of the regulator were rising and the braking action had begun. Soon the axle would reach its anticipated speed and stabilise.
Meanwhile he went on looking through the slit, but couldn’t see anything. He ran his hand over his sweat-pearled brow, as the bitter sensation of defeat began to weigh upon him, heavy as a boulder. Then all of a sudden a flash, followed by a flood of dazzling light, spread from the slit and exploded in his face. He instinctively raised an arm, shielding himself from the glare that seared his retina.
As he tried to react to his momentary blindness he heard a muffled groan from beside him. He had a vague glimpse of Bonatti staring in alarm at his face, illuminated by the flash.
‘The light of God!’ Dante cried, still shielding himself from the glare. ‘It moves … as everything moves!’
The shape of the heavens, that sought-after realm of the just that had always eluded
his words, was there in front of him right now, full of the splendour of creation. In his still-dazzled eyes the octagon drawn by the flashing lights seemed to dance in supernatural motion.
‘Frederick was right!’ he cried.
The astrologer shook his head firmly, several times. He had closed his eyes tight as though trying to keep from seeing anything. ‘You think you are victorious?’ he said after a long silence, broken only by the frantic roar of the spinning mechanism.
‘Yes! And here, in San Giovanni, here is my crown!’ Dante replied, still staring drunkenly at the flashing light. The image of the glory of the heavens, that image that he had sought for so long, was there now, in front of him, the Comedy was finally about to find its epilogue. ‘This was written by God in the nature of the boundless splendour, this my words will represent upon parchment, this men will read for their ultimate edification!’
Guido Bonatti looked petrified. ‘It isn’t … it isn’t possible!’ he stammered, moving towards the poet. He groped with his hands in the void, as if trying to grasp the rays of light to stop them. The poet stepped aside to let him look through the slot.
The astrologer shook his head for a moment as he began to bend towards the eyepiece. Then with a jerk he stepped back, crying out and covering his face with his hands, as if a living flame had escaped from the machine. An expression of despair replaced the sneer that he had worn a few moments before.
‘What have you to say about this sign, Messer Bonatti!’ the prior scoffed. ‘In what fallacious horoscope will its form now feature?’
The old man’s long hair, caught in one of the circular rays, looked as if it was on fire. Slowly he slipped on one of his gloves.
‘This is a work of magic. It isn’t true … it isn’t …’ he stammered. His left hand, now revealed, gleamed in the light. A silver hand.
The ‘incomplete man’. The cursed man of Mainardino.
Dante saw him activating something on his wrist with his good hand. His index and little fingers suddenly extended, turning into a pair of sparkling tongues.
At the sight of them Dante stepped backwards. Bonatti raised the weapon until it crossed the ray of light. The steel flashed in the brilliant light. He looked like an angel with his sword of fire.
‘Do you know this weapon, Messer Alighieri?’ the old man murmured, his voice suddenly calm. ‘Forged in Damascus and tempered in the blood of the prisoners by the caliph’s executioner. A man who had once been a thief, in his first life, mutilated by the butcher’s axe. It was for him that the craftsmen forged this hand, so that he could perform his duties.’
He had brought the two fingertips to his face and studied them carefully, as if he were only now discovering their singularity. ‘Another creation by those demons whose ingenuity you seem to love so much, to blind condemned men with a single blow. Do you see how the distance between these two fingers repeats the precise distance between a man’s eyes?’
He moved the weapon towards Dante’s face as though allowing him to check his words for himself. The poet stepped back once more, until he felt the cold stone of the wall behind him. The blades were approaching him dangerously, those blades that had killed so many men with their parallel jaws.
He lifted his arms in a bid to defend himself somehow. But Bonatti seemed not to want to strike. He stared with fascination at the blades plunged in the flood of light; then he bent over them with a sudden movement, piercing both his eyes. Horrified, Dante watched a scarlet flood pouring from the double wound, as the old man withdrew the blades without so much as a moan, his face reduced to a mask of blood.
‘If thine eye offend thee, pluck it out. So commands the Scripture. And so it is done. Not even the Emperor can defeat the plan of God. There is nothing your magic can do against my science,’ he gurgled, his teeth clenched in spasm.
Then he turned round, letting his arm drop along his side, and staggered forward. Dante ran up to help him, but Bonatti seemed unaware of anything, locked away in his own world of darkness and perfect repetitions. He stoutly brushed away the poet, as if he had sensed his presence through the scarlet veil that had deprived him of his sight.
He advanced towards the centre of the Baptistery. Dante watched after him, paralysed with emotion. He saw Bonatti approaching the baptismal fonts full of water, and stagger on to the edge of one of them. He swayed for a moment, seeking a hold in the void, then fell head-first into the round basin, plunging in to the knees. The water seethed with the old man’s efforts to re-emerge, and his legs waved desperately around. Beneath the shining waters his hands couldn’t find a grip and slipped on the smooth surface of the ancient Roman marble.
For a moment Dante didn’t react. He stood motionless, staring at that liquid death that punished the murderer precisely in line with his own premonition. Perhaps it had been right for such a thing to happen, bringing to an end the destiny begun half a century before.
Then a shock of rage dragged him from the torpor that had seized control of him. Bonatti would triumph, even in his despair, if his plan were accomplished. And the water would fill his lungs, passing through the grin of his lips. He would have the death of which his false science assured him. And he would triumph over Dante for ever.
He ran towards the basin, grabbing Bonatti by his ankles and trying to pull him from the water, now reduced to a bloody froth. The man’s body resisted, weighed down by the liquid that had drenched his long garments. Dante set his foot against the font and pulled with all his might. One of the little columns broke beneath the thrust, but the poet managed to maintain his hold until he dragged out the astrologer’s body.
Bonatti was still alive. He saw him propping himself up on his elbows, the mass of wet hair sticking to his head and hiding the mutilation of his face. Beside him, Dante tried to stay upright, his hands resting on his knees, panting with exertion.
They stayed like that for a few moments, before the astrologer suddenly rose to his feet as if some demonic power had taken control of him. The poet remembered what he had heard: sometimes dead bodies are possessed by the spirit of hell and brought back to life with its breath.
He saw Bonatti walking slowly towards the still-open door, leaving a bloody trail behind him, and disappearing in the maze of alleyways towards the north.
‘Liquid death refused you, Guido! Your science was inexact, as blind as your spirit!’ he called after him, but Bonatti did not seem to hear him.
All around him the strength of the crown of fire was waning as the phosphorous mixture lost its strength. Now all that remained was a pale shadow of the triumph of light that had illuminated the Baptistery with its splendour.
Dante bent and picked up the weapon, still covered with blood and scraps of bone. Al-Jazari’s machine was coming to rest with a final whirr.
Then he was overcome with emotion. As he slid down the wall, he felt his own senses sinking into the void.
AS HE came to, the poet found himself submerged in darkness that was barely attenuated by the moonlight flowing in from the windows. Some time must have passed, but how much? He felt a rough hand shaking him, and a harsh voice calling his name.
‘Wake up, Messer Durante! What happened?’
Dark shapes stirred around him, wandering through the empty space of the Baptistery. He recognised the squat outline of the Bargello, armoured from head to toe.
‘What happened, Prior?’ he heard him repeat suspiciously. ‘All this blood …’
Dante tried to get back on his feet, summoning the last of his strength.
‘The guard at the Porta ad Aquilonem called for help, thinking a fire had broken out in San Giovanni. When we got here the Baptistery was shining in the night as if a thousand torches were burning inside it. What happened?’ the head of the guards asked for the third time, pointing to the machinery in the corner and the mirrors still resting against the niches in the walls. ‘And who broke the balustrade of the fonts? Was it you? Have you gone mad? You will pay for this,’ he announced, with a hint of sat
isfaction in his voice.
Dante didn’t hear him. He went on staring at the darkness beyond the wide-open door through which Guido Bonatti had disappeared. Twice he thought he saw his shadow swaying in the distance, among the graves of San Lorenzo.
‘And what is all this?’ the Bargello asked, pointing to the machine and the mirrors.
The prior picked up Elias’ smoking lamp and looked at it carefully. A deep sigh emerged from his chest. ‘Light. The light that dreams are made of,’ he replied.
Then he walked slowly towards the night outside, beneath the stars.
AUTHOR’S NOTE
THE MACHINE dreamed up by Michael Scotus and realised by Arab mechanics, although plainly imaginary, is not entirely implausible. It broadly follows the lines of the one made by the Frenchman Armand Fizeau around the middle of the nineteenth century to determine the movement and speed of light.
The device is based on the use of two toothed wheels welded, slightly out of plane with one another, to an axle so that each interval between two teeth of the first wheel corresponds to a tooth of the second. After having set the axle to rotate at high speed, a ray of light is projected against the first wheel: this passes through the slit, is reflected against a mirror placed some distance away, and returns towards the second gear-wheel, which has by now rotated far enough to offer the light a new interval. By calculating the relation between the space travelled by the teeth of the gear-wheel and that passed by the ray of light, it is then possible to establish its speed to a good approximation.
Bearing in mind the relative simplicity of the apparatus, the Frenchman’s intuition could have been anticipated by the wise men who made the crown for Frederick the Great. That this did not in fact occur may be a source of regret for the historian, but does not greatly disturb the storyteller.
On the other hand, there is no need for the ray of light to travel along an octagonal trajectory, as imagined in the story: but so fascinated was I by the idea that the mysterious Castel del Monte might have been a kind of thirteenth-century tokamak that I risked presenting it as such to the reader.