National Geographic : 1936 Jul
THE HUB CITY, CRADLE OF AMERICAN LIBERTY A BEAM OF LIGHT, BROKEN UP BY A SPECTROGRAPH, MAKES THIS ARTIFICIAL RAINBOW Its face highly polished and lined with microscopic grooves, the mirror spreads a band of light, in which students at Massachusetts Institute of Technology distinguish more than 15,000 kinds of red and blue. On photographic plates, the mirror will register the unseen infra-red and ultra-violet light rays. "YOU CAN'T MAKE A SILK PURSE FROM A SOW'S EAR"-BUT LOOK AT THIS! Challenging that proverb, scientists in the Arthur D. Little laboratories ordered sows' ears from Chicago packers, compared their chemical structure with silkworm exudations-and so finally made this silk purse from a sow's ear.