Calibrated Arc

The bronze plate beneath my boots had absorbed the midday sun. I reached out and tested the angled gnomon with a gloved fist; the metal was rigid, casting a hard diagonal shade across numeral III. Beside the base lay a discarded brass watch spring, uncoiled into a fine spiral. I kicked the thin metal ribbon straight, wedging one tip beneath the bronze gnomon's edge and tensioning the curve across the engraved face. When I dropped my heel onto the release point, the spring snapped back with a sharp, singing hum, shearing cleanly through a dried seedpod resting two inches away. The response was instantaneous and precise. My tools are calibrated.