On the Classification of Stars of the § Cephei Class. 445 



" Volage " made it possible to extend the original programme so as 

 to include records of all the attendant phenomena. 



The paper gives an account of the preparation of instruments and 

 huts, and of the organisation of the " Volage " observers into 

 parties for different branches of the work. For the benefit of others 

 who may be similarly circumstanced on future occasions, full 

 particulars of these working parties and the instructions issued to 

 them are included in the paper, and the arrangements for working 

 the larger instruments are also described. 



On the morning of the eclipse the sky was almost entirely overcast, 

 and the sun was quite invisible during totality. 



No photographs were obtained, but some observations of tempera- 

 ture, colours of the landscape, and the general phenomena of totality 

 were secured. As shown by two thermometers screened from the 

 direct rajs of the sun, the temperature fell 0*9° F. from first contact 

 to totality, and rose the same amount between totality and last 

 contact. A fully exposed thermometer at another place indicated a 

 fall of 6'5° F., and a subsequent rise of 1'5° F. during the same 

 intervals. 



" On the Classification of Stars of the 8 Cephei Class." By 

 J. Norman Lockyer, C.B., F.R.S. Received May 17, — 

 Read June 17, 1897. 



Introduction. 



The spectrum of 8 Cephei is one of a group with special character- 

 istics. While containing a great number of fine metallic lines, giving 

 it more or less the same general appearance as the solar spectrum, it 

 shows many lines which are either faint in the solar spectrum or are 

 altogether absent. In a former paper* I showed that the spectrum 

 is practically identical with that of 7 Cygni, which my previous 

 work had indicated to be a star of increasing temperature. f 



The chief argument which I had employed in favour of placing 

 7 Cygni on the ascenclingjside of the temperature curve was based on 

 the presence of certain special lines, which occur with increased im- 

 portance, in the spectrum of a. Cygni, which differs very widely from 

 the solar spectrum, and has a close relationship to the Orion stars. 



Further, the association of a special kind of variability with some 

 of the stars having a spectrum of this type seemed to strengthen the 

 view that the constitution of such stars must be vastly different from 

 that of the sun. Dr. Vogel, however, has classified two stars of 

 the same group as 8 Cephei, namely, Aquilge and 10 Sagitta^ 



* ' Roy. Soc. Proc.,' vol. 59, p. 103. 

 f ' Phil. Trans.,' A, vol. 184, p. 718. 



