WORLD RANSACKED FOR SPECTROSCOPE PRISMS (Dec, 1933)
WORLD RANSACKED FOR SPECTROSCOPE PRISMS
New facts about health lamps are being discovered in a Cleveland, Ohio, laboratory by scientists armed with the largest spectroscope in the world. Behind the construction of this giant instrument lies a story that shows the lengths to which experimenters must go in obtaining the tools with which to work. When General Electric engineers set out to design an instrument technically known as a “double monochromator,” with which the intensity of any particular wave length of light could be measured with great precision, their plans called for prisms of crystalline quartz with faces four times as large as those commonly used. Quartz was needed because it transmits ultra-violet rays with undiminished strength. When an order was placed with a German optical firm for two triangular prisms, four inches high and six inches along the edges of the base, it was discovered that no single piece of crystalline quartz large enough to make such a prism was known to exist! A world-wide search followed. Finally, in Brazil, the needed crystals were found. Two gems of the optician’s art were producedâ€”a pair of prisms equalling in value a fair-sized house or a costly automobile. Mounted in the instrument, they enabled light from a lamp to be taken apart so that the desired color, or wave length, could be measured. Tests with the spectroscope will show how much ultra-violet light is needed to tan the skin.