Show I I j Air In Stratosphere Fight ng planes today fly the I I stratosphere s x or seven miles up m in air far too th n for human lungs Super charging or providing proper I Super atmospheric pressure in the cabins creates many engineering problems I many of which are far from corn com complete l t Engineers are study studying I I mg ing an ingenious system for the cab cabI cabin cabin in supercharger drive Obviously the higher the plane piano goes the faster must the supercharger run At low levels a speed of 2 rpm may be bej sufficient whereas an on of 30 feet may re a speed of 16 rpm The density of the air itself Itsell may provide an automat c con control control for the speed The fan tends to torun torun run faster as the plane rises with witha a consequent increase m in operating current |