Music: Hot Spot

Many a schoolboy has burned himself with his father’s magnifying glass. If he was a curious schoolboy he probably took the trouble to learn that the glass gathered together the sun’s diffused rays and concentrated them on one spot, raising their temperature to the burning point. But even that temperature was far lower than the 6,000º C. on the sun’s sizzling surface. Last week Chemist Robert Browning Sosman of U. S. Steel Corp., announced that by extending the principle of the magnifying glass he was able to capture half of the sun’s 6,000º heat. With a big specially-built heliostat (reflector) he reflected sunlight on a focusing mirror; the mirror concentrated the rays, focused them on a piece of zirconium oxide, which melts at 1960º C. The zirconium oxide was liquefied. Chemist Sosman estimated he had produced a temperature of 3,000º C.

Dr. Sosman expected his sun-heat to prove better than combustion or electric-resistance heating for laboratory work at high temperatures.