Yes, it's a mercury arc rectifier. When I was a kid I recall seeing one in the Scince Museum in London, and it was working at the time. Emitted a blue-green glow when it was working. The cathode was a pool of mercury at the bottom, the anodes were (I think) carbon rods in the tubes around the sides.
January 2016 Cartoon Caption ContestBob's punishment for missing his deadline was to be tied to his chair tantalizingly close to a disconnected cable, with one hand superglued to his desk and another to his chin, while the pages from his wall calendar were slowly torn away.122 comments