György Spiró - Captivity

“Something has ended in Alexandria,” said Apollonos Gamma sorrowfully. Tija waggled his head: for three hundred years, since Alexandria’s heyday, everything had indeed been decaying, but there was still plenty left to decay.

Uri conceived a big yearning to do some copying, and when it became apparent that rate of pay for copying mathematical treatises, which were considered difficult, was double, he decided to make himself known.

It was just that the Serapeion, in one of whose wings the Great Library was placed, was a temple. Was it possible for him, a Jewish newcomer, to enter such a temple?

Tija chuckled while reassuring him that the Eternal One would not be paying attention to where a Jewish believer was wandering off to in Alexandria: if he were, he would have struck Uri dead long ago. Anyway, Philo went there as well.

It was not easy to enter the Serapeion; Uri was requested for proof that he was a pupil at the Gymnasium, as well as a separate letter of recommendation from Isidoros.

He listed grumpily to Uri’s request.

“What do you need money for?” he asked. “The whole Jewish gang is keeping you going.”

“It’s not the money that’s of interest,” said Uri, “but the work.”

“Try another one. Do you believe you’ll come across a scroll of ballistic secrets, which you’ll memorize while copying them?”

Uri was astounded. Why ballistic in particular? Siege machines had never interested him.

“We’re in a time of peace, gymnasiarch,” said Uri. “There will be no war during my lifetime.”

Isidoros laughed.

“You’re naïve, my child,” he said, almost affectionately. “It’s a good thing there are some idiots among your generation.”

He gave his permission.

Tija went white with anger when he learned of this. Uri was surprised to find out that Apollonos Gamma had also asked about copying work, but Isidoros had refused to give him permission.

His suspicion was roused.

“Are you interested in firing ballista?” he posed the question.

Tija nodded.

“That’s the future,” he said. “The science of siege machines! My father is a simple exciseman, but I’m going to produce siege machines!”

Tija was especially interested in cannons that worked with compressed air. Experimentation with them had been abandoned a century ago because they had not approached the accuracy of conventional catapults, but still, he believed that the future belonged to compressed air. Uri did some reading up on this in the Gymnasium’s library.

Torsion catapults, which threw stone projectiles, had already been in use at the time of Alexander the Great, as were catapults for firing arrows, which remained standard weapons. But despite the attempts of Alexandrian scientists to replace these with compressed-air weapons, they never proved as effective as the torsion catapult. Ctesibius, Philon of Byzantium, and Strato of Lampsacus, that all-around genius of physics, had all excelled at constructing hydraulic machines. Ctesibius devised a torsion catapult that worked with a metallic wire, whereas Dionysius of Alexandria invented a repeating automatic catapult, the only trouble being that it did not fulfill the minimal requirement of being able throw a projectile at least one stadion. All the same, it was an impressive device, because as soon as it fired one arrow it readied itself to shoot again: it worked by virtue of a diminutive cylinder that fed the next arrow from a magazine into the slot.

But if it was possible to compress air, as had been proven, then it must also be possible to rarify it, reasoned Uri. The authors had written nothing about that because it was of no practical significance, and the idea had been promptly forgotten.

Tija was very fond of Philon’s book On Besieging and Defending Towns , which Uri also took a quick look at. This thorough author recorded notes on how food might be dried and preserved to feed a besieged town, how to ensure the health of its inhabitants, and how to prepare them psychologically. A substantial chapter was devoted to how the drinking water of the besiegers might be poisoned, how it might be possible to send messages from a besieged town to free towns, and to what sort of medicines should be stockpiled, along with observations on undermining the besiegers’ self-confidence. In another of the surviving complete parts of the series, the “Treatise on Mechanics,” the author dealt with the coding and decoding of reports from spies. It may have been from this source, in part, that the Jews of Judaea developed their use of fire signals. Tija also passed on to Uri a similar book by Aeneas Tacitus, which was less detailed but showed more inventiveness.

Uri was astonished: Why bother studying those works when there was no chance of Alexandria being under siege in the foreseeable future? Tija gaped:

“I read them from the reverse point of view,” he declared.

Bit by bit, it dawned on Uri that Tija was preparing to lay siege to cities, and he was studying these means of boosting their defenses to counter them.

“Do you suppose peace-loving Rome is making preparations for a siege?” he asked.

Seeing Uri as hopelessly naïve, Tija made a dismissive flip of the hand.

Uri began copying work in a small cubbyhole at the Serapeion, and he asked specifically to be given scrolls of mathematical works after it had been confirmed that copies of these would be given double pay.

It might well have been even more highly rewarded: a person had to pay great attention so as not to miss the signs for addition, division, squaring or cubing, roots, and so on that were placed beside the Greek script used to symbolize numbers. An isos sign used to denote equality, the noun-terminal “ es ” for an unknown quantity, and twice over was the multiple of an unknown; a dynamis was the sign for raising to the second power, kybos for a cube, a delta after a delta sign to mark raising to the fourth power, a delta and a kybos raising to the fifth power, a kybos after a kybos to indicate raising to the sixth power, and so forth.

The first nine letters of the Greek alphabet were used for the first nine numerals, 1–9; the next nine, to indicate the tens, 10–90, the third three, the hundreds; added to which the signs for the ligature, called a stigma , a qoppa , and a sampi, were taken from obsolete ancient Greek alphabets. To denote thousands a comma was placed before a number, the symbol M (for myriades ) stood for tens of thousands, and in a text a line was written above letters, which stood for numbers (unless it was forgotten). Uri had to transpose into this system a lot of texts written with earlier, divergent alphanumeric designations, and to accomplish this he often had to call upon the assistance of Heron, the supervising librarian, who was conversant with Egyptian and Phoenician scripts but impatient in giving explanations and, as Uri was later to discover, would often go astray in his own calculations. Heron was primarily interested in astronomy, though he did not scrutinize the sky himself, but rather preferred to delve into ancient writings. He was, incidentally, a learned, wise man; it was just that nitpicking, Sisyphean labors were not to his taste.

Copying was hard work, but Uri’s eyes were born for the task: he would bend his head close to the manuscript and could see everything perfectly, even better than the others who fiddled about beside him, because he was able to spot even the tiniest signs.

The end of the summer was spent copying; the bonus was that whatever Uri copied he took it upon himself to understand. Uri made an abacus and used that to check calculations; as a result he came to grasp many arithmetic and geometric relationships that previously he had failed to understand. In fact it was the regular mathematical instruction others had received earlier on from their private tutors at home, before going to the Gymnasium, that he missed most. Apollonos Gamma did admit that this was not true mathematics — that had ended two centuries before, during the civil war, with the flight to Cyprus of the legendary head librarian of Alexandria, Aristarchus of Samothrace. Apollonos considered that the Great Library had died intellectually even before Julius Cesar burned it down, adding pensively that perhaps Caesar’s flaming arrows would not have set the collection on fire if the spirit had still been alive in Alexandria. Even then, he ventured, the teaching staff were already not creative. Still, Uri could see clearly that there was still a thing or two that might be learned from them, so he defended them: a spirit was still alive in them, to be sure.