America's newest lethal chamber. Executions by gas instead of hanging. A new steel lethal chamber has been erected in the yard of the Missouri State Penitentiary at Jefferson City for executions under the new law, substituting lethal gas for hanging. The chamber has seats for two. When a lever is operated, cyanide pellets dropped into dire looted so feared acid to generate a deadly gas. From the outside, the appearance of the gas chamber resembles a submarine chamber. Photo shows, the new steel lethal chamber, resembling a submarine chamber, in the yard of the Missouri State Penitentiary at Jefferson City. 30 November 1937