AMERICAN 
JOURNAL OF SCIENCE AND ARTS, 
[THIRD SERIES] 
Art. IX.— On the Spectrum of the Aurora of October 14th, 1872; 
by GrorGE F, Barker. 
ANOTHER very brilliant aurora was visible in New Haven 
on the evening of October 14th, 1872. Like the one obsery 
the previous year—on the 9th of November, 1871—it was dis- 
tinguished by its intense crimson color, and by its form—which 
was that of a single broad streamer shooting up in the western 
sky from near the horizon almost to the zenith. The bright- 
The instrument used in examining its spectrum was a single 
prism spectroscope of Duboseq, similar to the one used for the 
aurora of November, 1871 (this Journal, III, ii, 465, Dec., 
1871). The prism is an equilateral one of flint, dense enough 
to distinctly separate the D lines with the magnifying power 
employed. The spectrum of the aurora, as seen in this instru- 
ment, was very bright and consisted of seven lines and bands, 
being markedly different from that of the aurora of Nov., 1871, 
the bands being crowded more together toward the middle of 
the spectrum. means of a candle flame the divisions on 
the millimeter scale were illuminated, and the sodium lin 
Were distinctly visible, the auroral lines could be clearly and 
sharply distinguished. The divisions of the scale which cut 
Am. Jour. a Vou. V, No. 26.—Fes., 1873. : 
