Make Your Own Vacuum Tube Kit
magazine ran an article, credited to Prof. Adolph Glockenspiel, describing a new do-it-yourself kit that allowed "any intelligent service technician with a minimum amount of experience" to make his own vacuum tubes, for little more than two cents per tube. The secret to the kit was the discovery of a new gas, Celosine, which made vacuum pumps unnecessary — these being hitherto the "almost insuperable obstacle to tube-making on a small scale." This newly discovered gas came in a solid form. When placed inside a tube, the celosine exploded as soon as the filament was heated, consuming all the gases in the tube and creating a very high vacuum.