1913 · Hot-Cathode X-Ray Tube · Work 1005 of 1,871
An industrial research laboratory in Schenectady on a winter night, on a slate-topped bench a large clear glass bulb about eighteen centimetres across lying in a wooden clamp, from one side a long glass arm ending in a metal screw cap, inside it a small cathode cup, from the opposite arm a stout metal rod reaching to the centre of the bulb and ending in an arrow-shaped tungsten head ground at a slant, one half of the glass glowing soft apple green, thick bare copper leads to both ends, a brass-rimmed ammeter with a plain dial and a bare pointer, a hand turning a black knob, frost on the dark window.