The Amber Disc

A cramped electronics workshop in Solna near Stockholm on an October night, on a scarred workbench under a desk lamp a thick round disc of clear amber casting resin six centimetres across and two centimetres thick, its rim glowing faintly reddish, sealed inside it a small silver cylinder on wire brackets, two plain black round cells, a bronze plate, fine green and red wires and a copper winding along the rim, from the disc two very thin wires in a wide loop, beside it a plain white plastic beaker that served as its mould, a soldering iron, one small transistor on a scrap of cardboard, two hands holding tweezers.