 The opening of this shatter, therefore, exposed the central part of the bolometer to such rays as are transmissible by glass. Between the shutter and the glass plate, and close to the latter, was a special screen composed of a thin stratum of asphaltum...  Lick Observatory Bulletins - Page 16by Lick Observatory - 1910Full view - About this book
 | Astronomical Society of the Pacific - 1907 - 686 pages
...composed of a thin stratum' of asphaltum varnish laid on one side of a plane parallel glas& plate 3mm thick. This screen was held out of the beam by a spring, except when designedly interposed. Its property, whenused, was to cut off nearly all the visible part of the radiation, while transmitting nearly all... | |
 | Astronomical Society of the Pacific - 1908 - 370 pages
...composed of a thin stratum of asphaltum varnish laid on one side of a plane parallel glass plate 3mm thick. This screen was held out of the beam by a spring, except when designedly interposed. Its property, whenused, was to cut off nearly all the visible part of the radiation, while transmitting nearly all... | |
 | Smithsonian Institution. Board of Regents - 1909 - 952 pages
...blackened metal shutter, which cut off the beam except when designedly opened. The opening of this shatter, therefore, exposed the central part of the bolometer...all of the infra-red rays transmissible by glass. By interposing this absorbing screen the proportion of the observed radiation which lay in the infra-red... | |
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