Peter Cooper Hewitt (1861-1921),US electrical engineer. Hewitt invented a mercury-vapour lamp (patented 1901) and built the first mercury arc rectifier (1902). Early models of the lamp were a thin tube with a pool of mercury filling the lamp with mercury vapour. Current flowing between electrodes and through the mercury vapour discharged a bluish-green light. The mercury arc rectifier,used to convert alternating current to direct current,was used in industry and on the railways. This signed 1918 photograph is from a collection of unpublished images obtained for 'The Pageant of America: A Pictorial History of the United States' (1925-1929) | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / NEW YORK PUBLIC LIBRARY / MIRIAM AND IRA D. WALLACH DIVISION OF ART, PRINTS AND PHOTOGRAPHS |
Bildgröße: | 2575 px × 3388 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |