Liquid oxygen for high-altitude flying, replacing the large tanks of gaseous oxygen kept under high pressure, may mean increased safety for the pilot, greater masneuverability, and added armament for the ship, because of the lower pressure used in storage and the reduced weight and size of the tank required. In commercial flying, more spice for passengers or cargo could be provided, according to Prof. John Akerman of the University of Minnesota, where the unit was developed. The new apparatus consists of a tank containing the liquid oxygen, enclosed within a large tank containing gaseous oxygen at about 80 pounds pressure. This compares with 1,800 pounds pressure under present methods, which presents the danger of explosion in the event it is struck by a bullet. As the gas escapes, the pressure is lowered, and then automatically the liquid oxygen is squirted into the enveloping tank, to become a gas by “boiling.”