All such feelings, however, were soon swept aside by a torrent of thoughts about his project. When he had told Ducetia that he was thinking of his work, he meant just that. For, while eating his dinner and savoring the memory of his contact with her, he had been struck by the resemblance between the motions of sexual intercourse and those of the parts of a catapult. Now more and more such ideas sprang into his mind—some fantastic or impractical; some worth noting.
He quickened his pace. At the inn they had no waxed tablets, papyrus, or parchment, so he bought a fresh-cut board. Over this he crouched in the flickering lamplight till midnight, covering the yellow wood with notes and sketches, until there was room for no more.
Zopyros expected to reach Syracuse the following afternoon. It began to rain, however, while he was passing through Megara Hyblaia, a Syracusan fortress and a squalid camp-followers' village built out of the ruins of a once fine city. Fearing lest the rain wash his notes off the board, which lay exposed athwart his cart, Zopyros knocked on the door of a hut. Although he was ordinarily too shy to ask for shelter of strangers, the thought of losing his precious notes nerved him to the ordeal.
The door opened a crack. "What do you want?" said a voice.
"I should like to come in out of the rain for a while, please—"
"Get out, vagabond!" The door slammed, and he heard the sound of a bolt's being drawn into place.
The rain showed no sign of letting up. He could not stand under the eaves of this house all night. If he tried to sleep against the wall, he might well have his throat cut. So he wrapped his cloak around the board, put it back in the cart, and went on to the fortress.
His Arsenal identification disk got him in. The officer in command offered him a small, unused room, in which he spent a restless, flea-bitten night. Just outside his door, a pair of soldiers diced noisily. They argued loudly in Oscan, got drunk, quarreled, started a fight, were reconciled, diced some more, and sang discordant peasant songs.
Around noon of the next day, Zopyros appeared with the board on his shoulder at Archytas' desk on the gallery of the Arsenal. Archytas said: "You've overstayed your leave, old boy, and you look a mess ... What in the name of the Dog is that?"
"Don't touch it; you'll smudge it. It's the solution to our catapult problem."
"Are you joking?"
"Not at all. If the big boss says anything about my being absent without leave, here's proof I was working for him all the time. Do you see this?"
"I see a lot of charcoal smears. What do they mean?"
Zopyros snatched a piece of papyrus and began drawing with quick, sure strokes. "Now, look here. Nothing says there has to be just one single trough, does it?"
"I suppose not."
"Well then, we'll have a main trough, fixed as in the present models. In this trough there shall be a big, deep groove, thus. Sliding back and forth in this groove, we have a slender, movable trough. We'll call it the 'slide.' This is a complex structure. At the after end it's nailed to the trigger assembly or crosshead. On its upper surface is a shallow groove for the missile. On the bottom it's keyed into the trough groove so it can't fly out.
"When we push the slide all the way forward, the trigger hook —call it the 'finger'—engages the bowstring. The windlass rope is tied to the trigger assembly. When we crank the windlass, we pull back trigger assembly, slide, and bowstring all at once. When the slide is as far back as we want it, we place the dart in the shallow groove and release the finger. The string snaps forward, sending the missile on its way. Then we unwind the windlass, push the slide forward, and start over."
"How do you hold the slide at the point from which you want to shoot the missile?"
"By a ratchet wheel on the windlass shaft and a pawl, as in the present movable-trigger model."
Archytas looked up. "By Earth and the gods, best one, I think you've thrown a triple six! This is jolly good. Wherever did you get the idea?"
"It came to me while I was—ah—um—while I was driving along the road on my way back."
"Perhaps you ought to spend all your time driving about Sicily, if this is what it does for you!" Archytas frowned. "I see trouble ahead, though."
"How so?"
"We're shorthanded. Most of the carpenters have been sent over to the shipyard to speed Alexis' supergalleys."
"Well, get 'em back! You're the executive."
"That's easier said than done. We shall have to carry our appeal clear up to Philistos, and we shall have to convince the wise Lithodomos first."
"Oh, I'd almost forgotten about him! Where is he?"
"Probably out to lunch with the other bosses. I'll find—"
A long, mournful toot struck Zopyros' ear. He started so sharply that he dropped his charcoal. "Good gods, what's that?"
Archytas grinned. "You're not the only one to invent things, you know!" He pointed to the mass of jars and tubes near his desk. The din of tools died away. The workmen swarmed out of the Arsenal, carrying the bags containing their lunches.
"So that's your alarm-clepsydra, eh?" said Zopyros.
"Yes. The big boss liked it so well that he makes me set it for noon and closing time as well as for dawn. I'm told—unofficially —that I shall get one of those medals at the next Arsenal banquet." Archytas carefully measured out a quantity of water into a graduated beaker and poured it into the uppermost jar. "But your invention is far more important, if it works. Meet me back here at the end of siesta, and I'll do my best with that god-detested idiot."
Lithodomos listened while Zopyros explained his plan. At the end he tossed his head back.
"I don't get it," he said. "You've got a sliding trough underneath, and a sliding trough above, and the dart in between them—"
"No, no!" said Zopyros. "The lower trough is fixed, while the upper trough moves back and forth along it."
"You mean the trough moves instead of the dart? You're going to shoot the trough at the enemy?"
"Let me begin again," said Zopyros, holding his temper with both hands.
After the mechanism had been explained, with drawings, three times, Lithodomos said: "I still can't understand it. I think that settles the question."
"How do you mean?"
"If it's too complicated for me, it's certainly too complicated for the ordinary soldier. I know I'm not so brilliant as you educated geniuses, but the people who use these things have even less technical training than I have. If I don't get it, you can bet your last drachma they won't."
Zopyros said: "Master Lithodomos, I don't expect everybody to grasp this mechanism at first sight. It's really not complicated—just unfamiliar. The main thing is to get enough carpenters to build one."
Lithodomos: "We're short of labor. I've tried to get men from the ship side, but I get only sweepings. If I do obtain a good man, a dozen other engineers have requests in for him. You'd need a fornicating good argument to get ahead of them. All I see here is a lot of complicated junk, which wouldn't work, and which no soldier could ever be taught to use if it did. Besides, all this complication means a higher cost. The President is always short of money."
"Well, what then?"
"If you was to go back to that catapult with a pivoted trough, I could see that. I might be able to get you help."
"No!"
"Why not?"
"We've been all through that. There are various ways of solving the problem of varying the range; and by the gods, I've hit on the best one! I'll bet my last drachma on this! If you want me to try the pivoted catapult later, I'm game; but I won't give up the most promising design until it's been tried out."