File:Glasses for protecting eyes from injurious radiations. (3rd ed.) (1919) (14596140109).jpg

Identifier: glassesforpro1919933cobl (find matches)
Title: Glasses for protecting eyes from injurious radiations. (3rd ed.)
Year: 1919 (1910s)
Authors: Coblentz, W.W. Emerson, W.B.
Subjects:
Publisher: National Bureau of Standards
Contributing Library: NIST Research Library
Digitizing Sponsor: NIST Research Library

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protecting the eye from ultra-violet light, black, amber,green, greenish-yellow, and red glasses are efficient. Spectaclesmade of white crown glass afford some protection from the extremeultra-violet rays which come from mercury-in-quartz lamps andfrom electric arcs between iron, copper, or carbon. The vaporsfrom these arcs emit but little infra-red radiation in comparisonwith the amount emitted in the visible and in the ultra-violet. For shielding the eye from infra-red rays deep-black, yellowish-green, sage-green, gold-plated, and bluish-green glasses are themost serviceable. For working near furnaces of molten iron orglass if considerable light is needed a light bluish-green or sage-green glass is efficient in obstructing the infra-red rays. For 53 Publication No. 65, p. 59, Carnegie Institution o? Washington: 1908. Glasses for Protecting the Eyes 21 working molten quartz, operating oxyacetylene or electric weld-ing apparatus, searchlights, or other intense sources of light, it is
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. 03ho . ft .. 1* is **: >> o* is C13J-J.ll*JSN&£UL AO&.3N3 important to wear the darkest glasses one can use, whether black,green (including gold-plated glasses), or yellowish-green, in orderto obstruct not only the infra-red but also the visible and theultra-violet rays. 2 2 Technologic Papers of the Bureau of Standards One can easily decide upon the kind of glasses to use to pro-tect the eye from the visible rays. The question is not so easilysettled concerning the elimination of the ultra-violet and theinfra-red rays. The data presented herewith give some clue as towhat can be accomplished in eliminating the infra-red rays. Data are given showing that of the infra-red rays emitted by afurnace heated to iooo to noo° C (i) about 99 per cent areobstructed by gold-plated glasses, (2) about 95 per cent by sage-green or bluish-green glasses, (3) about 60 to 80 per cent by verydeep-black glasses, and (4) about 60 per cent by greenish-yellowglasses. The dark shades of the

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