Selene studied the odd structure. Just in the time they had been watching, it had grown another fifteen feet. The side facing them and the roof extended as if by magic, like some living thing. "How will they use it?" she asked.
"They can assemble men inside it and we won't know how many or where they're concentrated. It can be opened up at any point and men can pour out to attack a weak spot on the wall. And they can use it to mask mining operations. Anywhere along its length, they can sink a shaft, then bore a gallery right under the walls, undermine them or pop up inside the city some night when nobody is expecting them."
"If they try that, they'll drown," she said confidently. "Here, if you dig down just a few feet, you hit water. The walls of Alexandria are sunk all the way down to bedrock."
"I hope you're right," Marcus said, "but Roman engineers are nothing if not ingenious. They may well think of something. Cutting you off from the river and the interior may be the point anyway."
"We're not cut off," she insisted. "The whole eastern plain is wide open, not a single Carthaginian soldier watching it."
"That's a trap," he told her. "They've left it open to tempt you to run. And it's being watched, but from the sea. If it should look necessary, they'll land there in force."
"So what shall we do?" she asked.
"First, let's get some of the catapults moved over here." But he knew they would have little effect. It would be nightfall before the catapults could be in position. And at night, the Romans would emerge to heap earth against the sides of the shed. They would absorb the catapult missiles and most of the rest would merely glance off the metal-sheathed roof.
He turned to study the new catapults, the gigantic staff-slings that had already wrought such devastation among the Carthaginians. Again he was amazed at the simplicity of their design, so simple that it seemed incredible that no one had thought of it before. The heavy timber base was merely the support for a giant pin on which the sling-arm pivoted. From the short end of the arm hung a great box on another pivot. This box contained tons of rock for a weight. Oxen drew the arm back until it almost touched the ground, where it was held in place by a bronze bar connected to a trigger. A sling almost as long as the arm itself was stretched beneath it and a specially cut stone placed in its pouch. One end of the sling was attached to the upper end of the arm, the other terminated in a ring that was slipped over a shallow hook at the upper terminal of the arm. When the trigger was tripped with a sledgehammer, the box dropped just a few feet but the arm was whipped upward with unbelievable force. The sling then swung up and the ring slipped off the hook and the stone flew just like a missile from a common sling, only a thousand times as heavy.
The only problem with the wonderful device, Marcus thought sourly, was that it couldn't hit anything closer than a hundred paces. And it was dreadfully slow to reload: capable of delivering only about four missiles per hour. The speed might be improved with intensive drill, but oxen could not be speeded up. And if the siege should prove to be lengthy, the oxen would be eaten and they would have to use men for the labor.
As he mused, it struck him how strange this was: advising a foreign queen on how best to defeat his fellow Romans. Not that she or anyone else had a prayer of doing that. Even moving all those catapults to the southern wall would probably produce few if any Roman casualties. Nonetheless, it felt strange.
In the gallery, the chief engineer, Mucius Mus, was urging his men to ever-greater speed. Legionaries, auxilia and slaves mingled indifferently, busy as ants as they passed the timbers and lead sheets and pins of wood or iron from hand to hand and the team of artisans fitted them together with wonderful skill.
"Hurry up with those timbers!" Mucius shouted. "Do you think we've all the buggering livelong day to finish this? I've seen half-tamed Gauls work harder than this and Gauls hate work! Do you want those buggering Alexandrians to think you're a bunch of buggering Greeks!" In truth he was well pleased with the men and their work, but his many long years as a centurion forbade his saying so. Customarily, soldiers only received praise from their general and then only after the battle was won.
Cato and Niger came down the shoreline behind the shed. Since only the north side of the shed would receive fire, the south wall was left open for the sake of light and ventilation, and to conserve material.
"When will it be finished?" Niger asked Mucius.
"If we can maintain this pace, I can have it extended all the way to the southeastern corner of the city wall by tomorrow morning," Mucius reported. "That is, if they allow us to keep up the pace. There could still be trouble. Matter of fact, if there's going to be trouble, we're going to see it soon. Look." He pointed to what was just beyond the end of the shed: Here the soft ground stopped and the pavement began. It was the city's river port. Its docks were deserted. The merchant vessels were headed for the Nile and even the fishing craft had withdrawn to the lake's southern shore.
"You see that big arch there?" Mucius went on. "That's the canal that connects the lake with the Eunostos Harbor. If I was the man in charge of defense, I'd send a warship or two out here to block us, maybe a sally of infantry to catch us while we're still at work and burn the gallery."
"If it happens, it won't be Parmenion that thought of it," Cato said. "Look up there." The others looked up through the archer's loop he indicated. They could see a man in Ro-man armor talking to a woman.
"Is that Scipio?" Niger said. "If it is, the woman must be Selene, the queen. Leave it to a Scipio not only to get himself appointed defender of Alexandria, but to bag himself a queen to warm his bed."
"I don't care what his job is or who he sticks it to," Mucius told them, "but if he gets just one of my men killed, I'll have him up before the Centuriate Assembly on charges of high treason."
Cato frowned. "I don't know what he's up to, but no Cornelian ever betrayed Rome."
Niger turned to Cato. "Send down a cohort of heavy infantry auxilia and another of skirmishers and all your archers. They can stand down here behind the gallery and be ready to take care of whatever comes through the arch."
Mucius scratched his chin. "That'll help. You know, to send ships out they'll have to raise the gate. If we're fast, we could get some men inside and keep it open. Get just one legion inside and we could take the city."
Niger and Cato looked at one another. "Only if Titus Norbanus orders it," Cato said. "We're not here to hand Alexandria to Hamilcar at the cost of Roman blood. And there'll be blood, never doubt it. A fight through the streets, with the enemy on the walls and the rooftops-we'd be giving away our biggest advantage by splitting up into a hundred units to take the city one street and one block at a time."
"Not to mention," Niger said, "giving Titus Norbanus eternal glory as the man who conquered Alexandria. He's not my patron that I owe him such favors. The man's never even held the office of praetor and here they've given him proconsular imperium. Let's just invest this south wall as we've been ordered and leave it at that."
"Suit yourselves," Mucius said, "but get those cohorts down here quick." When they were gone, he returned to tongue-lashing his men. Buggering senators, he thought. Always playing their buggering politics with my boys' lives.
The cohorts arrived in short order. The heavy infantry were mostly Germans from settlements now earning their citizenship: sons of wild tribesmen defeated by Noricum and sent to colonize the Gallic territory around Lake Lemannus. They were equipped much like the legionaries except for their flat, oval shields and their handheld spears that they wielded at close quarters instead of throwing them like pila. They were ideal for this job, Mucius thought.