Looking up at the board-formed reinforced-concrete soffit in the space above the vault at the Hoffmann-Hayman factory, photographed 5 October 2014 (Sony DSC-RX100) — same low-clearance vault zone as the WATCH YOUR HEAD frame — horizontal wood-form grain, grey paste with pits and pale efflorescence speckling, and **two thin bare copper wires** entering from the upper left and upper right to meet in a shallow V at a **through-bolt or stud** with hex nut and washer countersunk into the concrete, a simple uninsulated branch or bonding jumper fixed directly to the cast ceiling
