A Plumber's Balance Beam

That yellow folding ruler was just begging to become a proper bridge! I nudged two sections open into a neat right angle, propping one end against the zinc tray and the other right onto the iron body of the bench vise. Wahoo! I climbed up, planted my boots carefully along the narrow wooden edge, and held my arms straight out like a high-wire walker. Creak, creak went the wood, gently springing beneath my weight. I marched across all twenty centimeters without a single wobble, right into the metal vise's shadow. Perfect catwalk complete!