Daurenja nodded slowly. His expression showed that the diagram was the most wonderful thing he'd ever seen in his entire life.
"Steel girders," Ziani said, trying not to let Daurenja's manner bother him. "Really, it's just a steel cage. We build it where we want the cave-in to stop, if you follow me-"
"Perfectly."
Ziani ignored the interruption. "So we stuff the shaft with trash wood, charcoal, old rags soaked in lamp oil, set light to it-those bellows are a stroke of luck, we can get a nice burn going with a bit of air-and that'll burn out the timber props but leave the steel cage intact; it'll look like we've caved in the whole lot, of course, and then when the war's over, they'll only have to dig out as far as the cages; beyond that, the props should be unharmed. Quite simple, really, assuming it works."
"Brilliant."
Ziani ignored that, too. "The problems I can foresee are with what the heat might do to the cage. If it gets too hot we could warp the girders or even melt them, so we'll have to be careful not to get carried away. I'm hoping, though, that as soon as the props are charred halfway or three parts through they'll give way, and the falling rock'll snuff out the fire, or at the very least act as a heat-sink. The cage in the gallery ought to be straightforward enough, but I haven't made up my mind yet how best to anchor them in the vent shafts. They'll have a huge weight bearing directly on them from overhead, even if they're only ten feet or so down the shafts. We'll have to drive pins into the brickwork to take the weight; that'll be a fun job, swinging a sledge in such a tight place."
"I'll have a go if you like," Daurenja said immediately. "Back when I was working in the slate quarries-"
"They're miners," Ziani said, "let them do it. I'll want you with me in the fabrication shop, setting rivets. Not the most exciting job in the world, but it'll have to be done right. Then more riveting, of course, once we've got the bloody things into position."
"Not a problem," Daurenja said, as full of confidence as a lion roaring. "I did a great deal of riveting when I was working in the foundry, and-"
When Ziani had eventually managed to get rid of him, he put on his coat, drew a scarf over his face to filter out the worst of the dust, and went for a walk. He had pictured this place in his mind as long ago as his conversation with Miel Ducas, back in the Butter Pass, but back then it had been nothing but a geometrical design of wheels and levers. It was the ferocity of it that bothered him, the sheer brutality of falling iron-shod beams pounding rock into rubble. He wondered; he'd never seen a flour mill, even. He could feel the cracking and grinding and splintering in his bones, every time the cams tripped and the beams fell. It reminded him too much of things he'd only considered so far in the abstract, rather than in practice. Even the slaughter of the Mezentines, shot down in their thousands by the scorpion-bolts he'd made, hadn't affected him as much as this place did. There was a ruthlessness about it that he was reluctant to come to terms with. On the other hand, he was very close to resolving a number of issues that had been bothering him for some time, areas he'd left blank in the design, knowing they were possible but lacking the precise knowledge of detailed procedure and method. Not a comfortable place, but enlightening.
Daurenja, he thought, and he could feel his skin crawl. With any luck, the rope might break while he was dangling down a vent shaft in a bucket, and that'd be one fewer set of calculations to bother about. He tasted dust in his mouth, in spite of the scarf, and spat.
He walked toward the mine entrance, pausing to look up at one of the wheel towers. Crude, compared to a Mezentine waterwheel. There were no bearings to ease the turning of the spindle, and a significant amount of the water slopped past or over the blades, wasted. But he was here to sabotage the mines, not improve them. He shrugged. Fine by him.
A miner passed him, struggling with a wheelbarrow loaded with too much ore. As he went by he must've caught a glimpse of Ziani's face; he hesitated, the barrow wobbled and ran off line, making him stop. Ziani made an effort not to grin. He was getting used to being stared at, the only dark-skinned Mezentine in the duchy. It usually saved him the bother of having to explain who he was; everybody knew that already.
"Hang on a second," he called after the miner. "Can I ask you something?"
The man let go of the barrow handles and straightened up. "You're him, right?" he said. "The Mezentine."
Something else he was getting used to. Curious, to be known only for a quality he was no longer authorized to have, the thing that still defined him but had been taken away. "That's me," he said. "Ziani Vaatzes. Who're you?" he added.
The miner frowned, as if dubious about answering. "Corvus Vasa," he said. "I'm not anybody," he added quickly.
Ziani smiled. "It's all right," he said. "I just wanted to ask something, if you're not too busy."
Vasa shrugged. "Go ahead."
Ziani sat on the edge of the barrow. "I was talking to Superintendent Carnufex," he said, stressing the name and rank only very slightly, "and he was saying a man can dig ten feet of tunnel a day, average. Is that right?"
"Dig and prop, yes. I mean, usually there's at least four of you to a face, two digging and two propping, and four blokes'll usually do twenty foot a shift, two shifts a day, forty foot. So we say ten foot a man a day, as a rule of thumb, like. That's in earth," he added, "a bit less in clay. Plus, of course, you've got another two blokes coming up behind you to load the spoil, and another bloke to carry it. Teams of seven's the rule."
Ziani nodded. "Fine," he said. "What if you're cutting through rock?"
Vasa grinned sourly. "We don't," he said, "not if we can help it. You hit rock, best thing you can do is go back and work round it. Plus, you give the surveyor a right bollocking afterward."
"All right," Ziani said, "but supposing there's no way round and you've just got to cut through. That happens sometimes, doesn't it?"
Vasa nodded. "Sometimes," he said. "And it's a bastard. Then it's a man on the drill and another man to strike for him, cutting slots to fit wedges in. Two or three foot a day, depending on what sort of rock it is."
Aiani clicked his tongue. "What about granite?"
"Wouldn't know," Vasa replied, "never had to find out, luckily. I heard tell once that you can shift hard rock by lighting a bloody great big fire, get it really hot, then chuck water on it to split it." He grinned. "Sounds fine when you say it, but I wouldn't like doing it myself."
"I bet." Ziani smiled. "No granite in these parts, then."
"Never come across any. What d'you want to know about that stuff for, anyhow?"
"Oh, just another job I've got to do, sooner or later. Thanks, you've been a great help."
Vasa hesitated for a moment, then said, "They're saying you're here to block up the mine, because of the war. Is that right?"
"Afraid so. Means you'll be out of a job for a while, but think about it. If the Mezentines got hold of the mine intact they'd be wanting men to work it for them, and I don't suppose they'd be planning on paying any wages."
He could see the point sinking in, like water soaking away into peat. Then Vasa shrugged. "Let's hope the war's over soon, then," he said. "It's not a bucket of fun, this job, but it pays good money. I'd rather be here than on wall-building, like my brother-in-law. That's bloody hard work, and the money's a joke."
Ziani dipped his head in acknowledgment. "Vasa, did you say your name was?"
"Corvus Vasa. And there's my brother Bous, he works down on the faces, if ever you're looking for men for this other job of yours."