The central machine shop of Haven-Hold sounded like the inside of a huge, ticking grandfather clock.
Giles Croft stood before an oak workbench covered in brass shavings, gear cutters, and hair-width measuring tongs.
At the center of the bench sat a cast-bronze box two feet square, open at the top.
Inside the box was a bewildering maze of linked gears, differential gear-trains, and hardened steel spheres resting on revolving bronze discs.
Master Borin Bronze-Lung leaned over the gearwork with his jeweler’s magnifying glass pressed into his left eye socket.
The dwarf’s copper-braided beard was tucked into his leather vest to keep it from snagging in the gear teeth.
“Giles,” Borin muttered, his thick fingers hovering over a three-space-folding spiral cam machined from solid glowing-bronze. “I have cut gear teeth for watermills, catapults, and ore hoists for eighty years. But what in the name of the Stone Father is this spiral snail?”
“That’s a Napierian logarithmic cam,” Giles said, pointing his brass scriber at the curved surface.
