Word: spectra
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Dates: during 1890-1899
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Physical Colloquium. Papers: Series Spectra. Mr. E. H. Colpitts.- Transformation of Alternating Currents into Direct Currents. Professor Trowbridge. Jefferson Physical Laboratory...
Physical Colloquium. Papers: Series Spectra. Mr. E. H. Colpitts.- Transformation of Alternating Currents into Direct Currents. Professor Trowbridge. Jefferson Physical Laboratory...
...photographs of the spectra of the stars taken at the Harvard College Observatory as part of the Henry Draper Memorial differ in two respects from those ordinarily taken elsewhere. Instead of using a spectroscope with a slit, in which but one star is photographed at a time, large prism is placed over the object glass of the telescope and thus spectra of all the bright stars in the field of view are obtained. The number of stars photographed simultaneously is still further increased by substituting for the object glass a portrait lens like that used by photographers, only larger...
...results obtained show an important resemblance between meteors and stars having bright lines in their spectra, and may aid in determining the conditions of temperature and pressure in these bodies. Since bright meteors sometimes appear during the November meteoric shower a special effort will be made here to obtain photographs of them, both trails and spectra, tonight...
...several years the Harvard Observatory has been engaged in photographing, both in Cambridge and Peru, the spectra of all stars above the eighth magnitude. Professor Pickering hoped when this work was undertaken that a meteor would sometime cross the field of one of the photographic prisms while taking the spectra, but this did not occur until recently...