1887.] Researches on the Spectra of Meteorites. 143 



Manganese flame. 



Lecoq de Boisbaudran. — * Spectres Lumineux.' 



Work at Kensington. 

 Nora Orionis. 



Copeland. — ' Monthly Notices of the Royal Astronomical Society,' vol. 46 

 p. 109. 



a Orionis. 



Yogel. — ' Beobachtungen zu Bothkamp,' Heft 1, p. 20. 

 R. Greminorum. 



Yogel. — ' Astronomische Nachrichten,' No. 2000. 

 Meteorite Glow. 



Work at Kensington. 

 Schjellerup 152. 



Vogel.— ' Publicationen des Astrophysikalischen Observatoriums zu Potsdam,' 

 vol. 4, No. 14, p. 30. 



On the Absorption Phenomena of Stars iffWi bright Lines. 



In addition to the map showing the bright lines visible in those 

 stars the spectra of which contain them, I have prepared another 

 map showing the absorptions which also occur. The two maps 

 present a remarkable agreement — that is to say, there is the same 

 progression in the absorption phenomena as there is in the bright line 

 phenomena. In those stars in which bright lines are seen without 

 the lines of hydrogen (in which stars the meteorite swarm is probably 

 at a slightly higher temperature than that observed in the nebula 

 when only the line at 500 is visible) we have no marked absorption- 

 lines, but rather bands. When the hydrogen lines are added, as in 

 7 Cassiopeise, then we get the absorption of sodium and b of mag- 

 nesium, as we should expect. The individual meteorites therefore 

 are much cooler in these stars than in the Novas, seeing that the 

 absorption is so little developed. Speaking generally, therefore, we 

 may say that there are two causes of minimum absorption phenomena 

 in stars. In the first place, as in the bright-line stars, only a little 

 vapour surrounds each meteorite, and that vapour consists of the 

 substances visible at the lowest temperature ; while, on the other 

 hand, in stars like Sirius, in consequence of the absolute state of 

 vapour, we only get practically the absorption of hydrogen, or at all 

 events the absorption of hydrogen in great excess, due. I have very 

 little doubt, in part, to the fact that most other substances have been 

 dissociated by the intense heat resulting from the condensation of the 

 meteorites. 



Notes on the Provisional Temperature Curve. 



In order to bring the various results referred to in this communi- 

 cation in a definite form before my own mind, I have prepared a 

 diagram which I have called a temperature curve, so that on one side 

 of it we may consider those stages in the various heavenly bodies in 



