The rarefied state of stratosphere was as dangerously violent against the human-made air machine as it was to the human body. Despite oil emulsions on the wings, up here in this terrible cold, ice formed with deadly quickness on every part of the machine. In an instant, the plane was covered all over in a frozen layer an inch thick. Ice formed continually on the propeller, and was as quickly thrown off in terrible vibrations that near tore the motor mechanisms asunder.