Abstract
MESSRS. CHANCE BROTHERS, LTD., Smethwick, have produced a new glass to be known as Type No. O.N.19. It is available in rolled sheets with semi-diffusing surfaces, and for optical purposes requires to be ground and polished. The rolled sheet is usually 5-6 mm. thick. It has a coefficient of expansion lower than ordinary glass and hence is less liable to fracture when subjected to stresses due to given thermal changes ; coefficient of linear expansion per degree centigrade (0-100°) is 54 x 10-7. It is claimed that it is more efficient as a transmitter of visible light and a heat absorber than any other glass previously made in Britain. It is at least equal to any previously available from foreign sources: for radiation from a source at 2,848° K. and a thickness of glass of 2 mm., the total light and heat transmissions are 88 and 14 per cent approximately ; for glass 3 mm. thick the figures quoted are 87 and 8-5 per cent respectively.
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New Optical Glass. Nature 157, 689 (1946). https://doi.org/10.1038/157689c0
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DOI: https://doi.org/10.1038/157689c0