STEVENS LECTURES ON STRATOSPHERE FLYING

"The future of high airplane flying depends more on propeller than on wing design," said Major Albert W. Stevens, famous stratosphere explorer, in a lecture before 150 people, at the Geographical Institute last night.

Taking as his topic "High Altitude Flying by Airplane," Stevens, U. S. Army Air Corps, discused the future of stratosphere flying and its obstacles. He emphasized the fact that it was possible by means of superchargers, blowers designed to send compressed air to the engine, to fly higher than 100,000 feet, although at a height of 60,000 feet air density is one-eight that of sea level.

"Can't Fool Propeller"

"While you can fool the engine, you can't fool the propeller," he remarked. "The problem now is to get a propeller which can turn fast enough. At 75,000 feet, the diameter of the propeller must be four and a half times that of a regular propeller. As it turns at swift speeds, the resistance increases 10 to 15 times."