1888.] of the various Species of Heavenly Bodies. 33 



spectrum, which at first sight appear due to absorption, are shown to 

 be most likely caused by defect of radiation in that part of the 

 spectrum between the blue end of the continuous spectrum from the 

 meteorites, and the bright band of carbon. 



All the observations, it would appear, can be explained on the 

 assumption of low temperature. 



Notes on the Maps. 



7 Argus. — R.A. 8h. 5 m. 56s., Dec. —46° 59*5'. Respighi and 

 myself observed the bright lines in the spectrum of this star at 

 Madras in 1871. No measurements were made of the wave-lengths 

 of the lines, which were observed by Ellery at Melbourne in 1879, and 

 given as 5760, 5648, and 4682. Other bright lines were suspected. 



Copeland examined and mapped the spectrum of this star while in 

 the Andes in 1883. His wave-lengths are 5809, 566*8, 464*6, and 

 a fainter line at 590. The continuous spectrum extends from 420 to 

 675, the lines being seen bright on this, but no mention is made by 

 either Ellery or Copeland of absorption of any kind. The bright lines 

 at 590 and 566*8 are most probably the lines of sodium, 5890 — 95 and 

 5687 ; the 580*9 line is probably the 579 strongest low-temperature 

 line of iron ; and the 468 (464*6 Copeland) is due to the carbon fluting, 

 which has its maximum intensity at 468, the other carbon flutings at 

 517 and 564, being rendered invisible to Copeland by the bright con- 

 tinuous spectrum, although Ellery's measurement of 564*8 is most 

 probably the carbon band at that point. The 517 carbon may have 

 been seen by Ellery, for although no measurements are given he saw 

 other bright lines or spaces. The dark band 474 to 486 seen in the 

 Cygnus stars, Argelander-Oeltzen 17681, and Lalande 13412, being 

 due to the shortness of the continuous spectrum, and the appearance 

 of the carbon band beyond the blue end, is not seen in this star, 

 because it has a long continuous spectrum. 



The bright lines seen in it are due to low temperature sodium and 

 iron, and to carbon flutings on a bright continuous spectrum. 



B-espighi's observations are given in ' Comptes Rendus,' vol. 74, 

 p. 516 ; Ellery's results are given in a letter to ' The Observatory * 

 vol. 2, p. 418 ; Copeland's are published in ' Copernicus,' vol. 3, 

 p. 204. 



Argelander-Oeltzen 17681. — Two observers have examined and 

 mapped the spectrum of this star, Dr. Yogel at Potsdam, and 

 Professor Pickering at Harvard College. Both give the wave-lengths 

 of the lines observed, while in addition Dr. Yogel publishes a sketch 

 of the spectrum as it appeared to him. 



Vogel's strongest line is at 581. This Pickering measures as- 

 VOL. xliv. d 



