238 On the Temperature Classification of Stars. [Jan. 30, 



and the relative intensity of the red is increased, as a lower temperature 

 is reached. That is to say that where two spectra having their inten- 

 sities about the region Hp — H ? equal are compared, we find that in th*e 

 cooler stars, according to the chemical classification, the emissions in 

 the red preponderate, whilst in the hotter star the ultra-violet is more 

 extended and intense. 



My best thanks are due to Messrs. Eolston and Goodson, who took 

 the various photographs to which I have referred, the former also 

 helping me in the preparation of this paper, and to Mr. AVilkie^for 

 preparing the enlargements of the negatives. 



9. Description of Plates. 



No. 



No. of 

 negative. 



Stars. 



19 

 14 

 37 



11 



35 

 34 



36 

 23 

 33 



Plate 7. 



fVega 



1 Arcturus . . 



f Castor . 

 \ Capella 



f Castor . 

 \ Capella 



Plate 8. 



Eigel 

 Sirius 



k Orionis. 

 Eigel 



j" 7 TJrsse Maj. 

 \ a Ursae Maj . 



Plate 9. 



j T] Ursse Maj. 

 \ Capella. . 



Alnitam 

 1 Procvon 



j Alnitam 



X Aldebaran .. 



Stage, i Type. 



CXI. 



Arct. 



Sir. 

 Arct. 



Sir. 

 Arct. 



Eig. 

 Sir. 



Alnit. 

 Eig. 



Mark. 

 Arct. 



Cruc. 

 Arct. 



Alnit. 

 Proc. 



Alnit. 

 Aldeb. 



In producing these plates the original negatives have been enlarged 

 about . 3 J times. 



