AEG, a lighting company in Berlin, bought the Nernst s patent for one million German gold marks, which was a fortune at the time, and used 800 of Nernst lamps to illuminate their both at the world s fair Exposition Universelle ( 1900 ).
12.
In addition to their usage for ordinary electric illumination, Nernst lamps were used in one of the first practical long-distance photoelectric facsimile ( fax ) systems, designed by professor Arthur Korn in 1902, in Allvar Gullstrand's slit lamp ( 1911 ) for ophthalmology, for projection and in microscopy.
13.
After Nernst lamps fell into obsolescence " Nernst glowers " went on to be used as the infrared-emitting source used in IR spectroscopy devices . ( Recently, even this has become obsolete as Nernst glowers have been largely replaced for this purpose by silicon carbide glow bars or " globars ", which are conductive even at room temperature and therefore need no preheating .)
