Mara drew the composite on the bench in chalk, and then in pencil.
The bench beside the oiled tools. She cleared a space among the grey caps and the shims and laid a sheet of guild paper on the iron, and Tavin stood at her shoulder, and Sen at the bench’s end, and the crew chief came out of the passage and crouched at the bench’s corner with his cap in his hands.
Chalk first. Rough. On the bench’s iron itself, beside the paper, so she could see the shape before she committed it. A rib. Long. Curved to the lattice’s curve. Three parts.
The foot: crown iron. The same crown iron as the crown patch at Lorn, dense and hard, to seat in the socket’s stepped groove and take the cage’s load where the rib met the wall.
The middle: water-main alloy. Tavin’s bar. Grey and flat and unremarkable, to flex as the lattice cycled hot and cold, to pass the load along without keeping it.
The lining: mirror iron. A strip, along the rib’s inner face, at thirty-one degrees, to turn the load the way the seventh channel turned a pulse: outward, into the cage, instead of back into the bow.
