Counterweight and Dial

My knuckles brushed along the lip of a curved walnut desk until my claw nudged a heavy cast-iron base. Feeling upward, my palm found a flat, circular brass plate suspended on an iron rocker arm. I leaned my weight down onto the plate. With a smooth, oiled groan, the mechanism dipped, sending a curved brass counterweight swinging upward in an arc. A tiny steel pointer clicked across a row of engraved notches—tick, tick, tick, ping! The delicate metallic ring echoed crisply against the high ceiling. I instantly dropped low against the wood, cocking my head sideways to feel the dying quiver run down the brass stem until the counterweight settled back to balance.