United States or Italy ? Vote for the TOP Country of the Week !
Searle, Harvard Annals, vol. xxix., p. 223; Boss, Astr. Roy. Messenger, vol. iv., p. 282; Hasselberg, Astr. Roy. Astr. Pac. Nach., Nos. 3,752, 3,753; Kapteyn, Ibid., No. 3,756; F. W. Very, Ibid., No. 3,771; and W. E. Wilson, Proc. Roy. Trans., vol. clviii., p. 540. Nach., No. 3,476; Astroph. Roy. Astr. Pac. Soc., vol. ii., p. 265; Proc. Roy.
At Potsdam, the bright yellow line was perceived with astonishment by Vogel on May 31, and was next evening identified with Fraunhofer's "D." Its character led him to infer a very considerable density in the glowing vapour emitting it. Hasselberg founded an additional argument in favour of the electrical origin of cometary light on the changes in the spectrum of comet Wells.
Equally indecisive information was derived from the spectroscope. To Vogel, Hasselberg, and Young, the light of the "Nova" seemed perfectly continuous; but Huggins caught traces of bright lines on September 2, confirmed on the 9th; and Copeland succeeded, on September 30, in measuring three bright bands with an acute-angled prism specially constructed for the purpose.
Some minor deviations from the laboratory pattern, in the shifting of the maxima of light from the edge towards the middle of the yellow and blue bands, have been experimentally reproduced by Vogel and Hasselberg in tubes containing a mixture of carbonic oxide with olefiant gas.
The labour of collation was well advanced when he died at the age of fifty-two, April 16, 1901. Investigations of metallic arc-spectra have also been carried out with signal success by Hasselberg, Kayser and Runge, O. Lohse, and others. Another condition sine quâ non of progress in this department is the separation of true solar lines from those produced by absorption in our own atmosphere.
Word Of The Day