Evening Republican, Volume 23, Number 306, Rensselaer, Jasper County, 23 December 1920 — How Airmen Use Oxygen. [ARTICLE]

How Airmen Use Oxygen.

When the airman ascends to heights greater than 20,000 feet, he is sure to use oxygen. He carries it in liquid form in a vacuum tank provided with a mechanism to control the evaporation. The liquid may be electrically heated to accelerate evaporation; or a heated rod of copper or aluminum in the liquid may be used; or the liquid may be siphoned out into an evaporating chamber from which the gas is conducted through tubes to the airman’s mouth. Popular Science Monthly.