Cyanide vat, Bodie, California, USA

A 1930s era vat made of steel. It is located on the ridge east of the main part of Bodie. There was an attempt to revive Bodie in the early 1930s that foundered due to a fire, because after the fire they couldn't raise additional capital due to the Depression. This historical accident is probably why Bodie is preserved today.

Btw, the cyaniding reaction requires oxygen, and hence exposure to the air. That's why the reaction vessels are "vats," implying a relatively shallow container with lots of surface area. It was discovered early on that nothing happened if you just put the cyanide solution and ore together in a tank in the absence of air.