1889.] Neb aim and Stars ivith those of Comets and Aurora?. 35 



The coincidences here are between the flutings of hot carbon, 

 manganese 558, and Pb,Na 568. D has only been seen bright in one 

 of the stars (7- Argus), which is probably one of the hottest ; since 

 D was seen bright in two of the hottest comets, I have inserted it in 

 the list of cometary lines and flutings, and [527] and [579] are added 

 for the same reason. 



Although nine lines or flutings are common to comets and bright- 

 iine stars, six occur in comets which do not appear in bright- 

 line stars, and five in bright-line stars which do not appear in 

 comets. 



The apparent absence of hydrogen from comets has already been 

 referred to, as well as the absence of D 3 . The cool carbon flutings 

 are not seen in the bright-line stars because the temperature is too 

 high, and Mg 500 is absent for the same reason ; Mg 521 is pro- 

 bably also absent because of the higher temperature. The lead 

 fluting at 546 may be masked by continuous spectrum in the bright- 

 line stars ; at all events, it appears as an absorption-band when the 

 swarms further coudense. Besides the hydrogen and D 3 lines, 

 the lines 50 7, 540, and 635 appear in bright-line stars, but not in 

 comets. 



IV. Comparison of Comets and Stars of the Mixed Fluting 



Group. 



In the Bakerian Lecture I also gave evidence to show that stars of 

 Group II (Vogel's Class Ilia) are of a cometary character, and a 

 little more condensed than the bright- line stars. The grounds on 

 which this conclusion was arrived at was the probable presence of 

 bright carbon flutings, in addition to the metallic absorptions. 

 Observations of a-Herculis and Mira "Ceti by Mr. Fowler at Ken- 

 sington and by myself at Westgate-on-Sea have fully confirmed this 

 view. The rapid increase of brilliancy of the flutings of Mira at its 

 maximum in 1888 left little doubt in my mind that they were due to 

 carbon, and Mr. Fowler's comparisons showed perfect coincidences 

 with the carbon flutings, with the dispersion of two prisms 

 of 60°. 



Some of the origins which I suggested for the dark bands have 

 also been tested by direct comparisons. Duner's bands 4 and 5 were 

 found to be coincident with the manganese and lead flutings at 558 

 and 546 respectively, and band 3 was found to be coincident with the 

 maganese fluting about 586. 



[Mr. Maunder observed the spectrum of «-Orionis on December 16, 

 1887, and made comparisons with the spectra of carbon, sodium, and 

 manganese, as given by a Bunsen flame. He states the results as 



d 2 



