Word: selenium
(lookup in dictionary)
(lookup stats)
Dates: during 1920-1929
Sort By: most recent first
(reverse)
...presence of as little as one part of mercury in 20,000,000 parts of atmosphere. Before the poison is detected by symptoms of illness in drooping employes, a coating of yellow sulphide on a strip of paper gives the signal by turning black (the result of contact between selenium sulphide and mercury). The degree of blackness is photographed by shining a light through the strip of yellow sulphide. If the sulphide has turned dark, less light will penetrate; if black, no light will penetrate. This is recorded on an ammeter legible to every...
...score gentlemen who went were impressed deeply by the ingenuity of Mr. Baird's "optical lever," a series of whirling lenses mounted on discs, which break up an optical image into minute constituent parts. They were even more impressed by the Baird photo-electric cell, of the colloidal selenium type, which could capture and transmit the minute image parts at unprecedented speed. Last week, between sessions of the British Association, members sought out Inventor Baird in Leeds to see him manipulate his latest tele-visors, which are now so refined that they can "see things at night." Using infra...
...Marconi that "it will soon be possible to transmit a picture or a whole page of print across the Atlantic by radio," was amplified. Marconi's prophecy, it appeared, was based on the development, in various European laboratories, of a new photo-electric cell, much more sensitive than the selenium cells hitherto used with indifferent results. The inventor of the cell was one Dr. Carolus, who had based his work on the so-called Kerr method of influencing polarized light so that high voltage produces a strong light ray, low voltage a weak ray. The Carolus cell, which...
...instrument, called the "luminaphone," releases light from a series of searchlights to strike through a pattern of holes on revolving disks. Each hole is the equivalent of a note of music. The light, interrupted so as to form the pattern of a tune, passes through the holes to strike selenium plates, setting up vibrations which are "amplified" as on a radio. When Inventor Grindell-Matthews placed his hand over one of the lights, a note was deadened; when all the lights were covered, all sounds ceased. The instrument has a tone like that of a little pipe-organ...
...Selenium insulation for electric wires was the contribution of Adviser Little to better fire protection...