STRATOSPHERE TRAVEL

Evening Star, Issue 22248, 28 January 1936, Page 11

STRATOSPHERE TRAVEL

PROSPECTS OF THE FUTURE Travel in the stratosphere “ within the lifetime of many of ' ls . IT .' v ? s visualised by Professor G. T. R. Hill in an address before the Royal Society ot Arts in London. Professor Hill, who is Kennedy Professor of Engineering at London University, spoke of the difficulties to be overcome before flying could be achieved in the mysterious regions many miles above the earth, where human beings would burst if unprotected, steel would become red-hot and brass melt. “ Pressure cabins must come,” he said, “ and they will be tried first at moderate altitudes with small internal pressures. As the confidence of the public is won by fine records of safety, so really high altitude flying will conic into its own. -Ptofessor Hill referred to one problem of stratosphere flying that is not generally appreciated, arising by reason of the fact that the speed of sound in air is only about 700 miles an hour. This had a profound effect on the whole technique of high-speed aeroplane design, he said. At the present speeds of flight every exposed part of the aeroplane pushed what he described as a il bow wave )9 in front of it. If the aeroplane was travelling faster than 700 miles per hour, this “bow wave” could not travel ahead and warn the air to get moving so that the familiar .streamline flow could be produced. “ Far up into the stratosphere the temperature actually rises,” he said. “At 160,000 ft—-some 30 miles up—it is believed to be about as warm as on the ground, and 200 miles up the temperature has risen so much that a piece of steel, if it were up there, would melt.’ Speaking on the problems of oxygen supply for crew and passengers, Professor Hill said it was absolutely necessary to avoid putting the pressure inside a man without putting it outside.