40 Dr. and Mrs. Huggins. On Wolf <m<l [Dec. 11, 



great body of bright 7-adiation lies far tayond the ordinary visible 

 limit of the blue carbon band, and no connexion whatever with 

 carbon is even suggested to us by the star's spectrum. Dr. 

 Copeland's measure of the band in 1884 was X 465*4. 



The continuous spectrum of the star is unequally bright from the 

 presence of bright groups and also apparently of absorption bands or 

 lines, and therefore with small dispersion it might be easily supposed 

 that the spectrum is brighter at the position of the green carbon 

 band. We examined the continuous spectrum repeatedly with great 

 care, and we were able to satisfy ourselves that, under the consider- 

 able dispersion of our instruments, there was no sensible brightening 

 of the spectrum at the positions of the green and of the orange bands 

 of the Bunsen flame. 



No. 3956. Vogel places the brightest part of the band in this star 

 at the same position in the spectrum as in the star last considered. 

 No. 4013, namely, at X 464, a position beyond the carbon band. The 

 position of the band as it appeared in spectroscope B with the third 

 eye-piece, is represented at No. 6 in the diagram. The position of 

 the band relatively to that of the Bunsen flame was determined by 

 estimations made by means of the intervals between the bright 

 flutings of the Bnusen band. The position agrees substantially with 

 that given by Vogel, but places the maximum brightness nearer to 

 465. This bright part probably consists of a group of bright lines 

 and falls off rather suddenly at both ends. We were not certain if 

 the light beyond this bright part was due to a continuation of the 

 band or to the continuous spectrum, more or less dimmed by absorp- 

 tion ; we have, therefore, left the ends of the band incompleted in the 

 diagram. Copeland's measure of this band in 1884 was X 464'9. 



The sub-band seen in the star No. 4013 is very much fainter in this 

 star, but we have little doubt that there is a very faint band present 

 at about the same place in the spectrum. 



Professor E. C. Pickering has found in the near neighbourhood of 

 these three stars other stars possessing bright lines in their spectra.* 

 The brightest of these, independently discovered by Dr. Copeland in 

 1884,f namely, D.M. + 37 3821, in which the spectrum is similar 

 to that of the Wolf-Bayet stars, was examined. Dr. Copeland says 

 of this star : " It has a spectrum of several bright lines near D, and 

 a very bright band in wave-length 464 " (loc. dt.~). We were therefore 



* "The following list contains the designations of all eight stars (with bright 

 lines), the first four being those previously known : 35 4001, 35 4013, 36 3956, 

 36 3987, 37 3821, 38 4010, 37 3871, 85 3952 or 3953. Of these 37 3871 is 

 P Cygni, and 37 3821 is the star in the spectrum of which the bright lines are most 

 distinct" (letter in 'Nature,' vol. 34, p. 440). 



t ' Monthly Notices, R.A.S.,' TO!. 45, p. 91, 1884. 



