The Red-Black Columns

An exhibition hall in Turin on a summer evening, warm light from incandescent lamps on a brass chandelier, bare cream-painted walls, on a dark wooden platform three upright columns forty-six centimetres high, each between two brown wooden end plates with bevelled corners joined by four bright steel rods with hexagon nuts, between the plates a cylinder of hundreds of wedge-shaped copper tabs in spiral rows lacquered alternately red and black, at the front a round brass ring around a central opening, four brass terminals, a small plain brass plate, red cotton-covered wires on top, a hand in a dark sleeve drawing a nickel-plated knob and its iron core out of one column.