The Stacked Valve

The windowless valve hall of a direct-current converter station on Gotland on an April night, cold even light from rows of fluorescent tubes under a concrete ceiling, at the centre a valve tower two metres sixty high, about sixteen flat rounded metal plates stacked horizontally, joined at the sides by leads, a curved tube bow on top, below a grey box-shaped base with four round instruments with blank faces and small green lamps, beside it a reactor coil of cream-yellow curved ribs with rust-brown bars and two black end rings on chocolate- brown porcelain insulators, every surface plain and unmarked, older red and green valves soft behind a yellow mesh fence.