1888.] of the various Species of Heavenly Bodies. 



45 



D 3 line. ('Bull. Meteorol. du College Romain,' 31 Juillet, 1863, 

 p. 108.) 



Vogel on June 19th, 1872 observed a bright line in the greenish- 

 blue 486, and one in the yellow which he assumes to be D 3 . An 

 absorption band was also noticed in the red, but its wave-length was 

 not determined. ('Both. Beob.,' Heft 2, p. 29.) 



Great stress was laid on the fact that the bright lines died out 

 between 1874 and 1883, when they were observed by Gothard, but on 

 December 26th, 1879, C was noted as " superbly visible " by Lord 

 Lindsay, J. G. Lohse and Dr. R. Copeland, and two bright lines, one 

 evidently F, observed on October 28th, 1877. No mention is made of 

 C in the records of the observation. (' Monthly Notices of the R. 

 Astron. Soc.,' vol. 47, p. 92.) 



Konkoly examined 7 Cass, (and /3 Lyree) repeatedly between 1874 

 and 1883, without seeing bright lines ; Gothard repeatedly examined 

 both stars after the autumn of 1881, but saw no trace of bright lines 

 until 1883. (' Astr. Nachr.,' 2581.) 



The Greenwich observations for October 1st, and November 21st, 

 1880, December 7th, 1881, and November 16th, 1883, show the F line 

 bright. No mention is made of bright D 3 or C, but only F was being 

 used to measure velocity in line of sight, and so the others may not 

 have been particularly noted. 



Gothard, in ' Astr. Nachr.,' No. 2539, records his observations on 

 August 20th, 1883, when C, F, D 3 , and the absorption band at 

 633 were visible. 



Konkoly took up this work at once, and in the O'Gyalla Observa- 

 tions we find two sketches of the spectrum as seen by him. In the 

 first C and F are bright lines sharply defined. D 3 is seen as a bright 

 line, while between D 3 and F is a bright patch of light extending 

 from near 520 to 560. This seems to be absent in the second 

 spectrum, while dark b lines and dark D are added as well as bright 

 hydrogen G with a dark line near it. 



Sherman at Yale College Observatory records all the bright lines 

 previously observed and many others in addition, but while dark lines 

 are recorded by him, D and b are not mentioned. 



Gothard (' Astr. Nachr.,' No. 2881) has observed Ha, H/3, and 

 H<y as dark lines in /3 Lyrse, and afterwards as bright lines. 



Sherman's observations, in which no mention is made of dark D 

 lines, are of extreme interest, indicating as they do that the sodium 

 line absorption was masked by the bright radiation of manganese,, 

 which produces a bright fluting almost exactly in the position of 

 D 3 . Gothard, in 'Astr. Nachr.,' No. 2581, records the fact that 

 the dark sodium lines became visible only when D 3 had ceased 

 to be seen as a bright line. Later on in the same paper, however, 

 he records bright D 3 and dark D in /3 Lyrae, and Konkoly, in 



