Within one month of the arrival of the news of anesthesia arriving in London, John Snow had investigated the properties of ether, established the concentrations required and designed, tested and published the results of using a vaporizing device. The top image shows the ether chamber with the bottom removed to show the interior. The volute, of the same metal as the chamber, is soldered to the top, and reaches to one-sixteenth of an inch from the bottom. The bottom image show the face mask. The dotted lines indicate the position of the expiatory valve when turned aside for the admission of un-vaporized air.