1887.] Researches on the Spectra of Meteorites. 131 



produced by the incandescent vapour surrounding the individual 

 meteorites which have been rendered intensely hot by collisions. 



These stars, therefore, are not masses of vapour like our sun, but 

 clouds of incandescent stones. 



We have here probably the first stage of meteoritic condensation. 



The Cases of Nova Orionis and R. Geminorum. 



The stars with bright carbon fiutings, the same as those seen in 

 ■ .comets, are not limited to first- magnitude stars, such as a. Orionis, 

 but include at least one new star, Nova Orionis. Because the latter 

 star lasted but a short time we might expect the phenomena pre- 

 sented to be different from those found in the first- magnitude star, 

 which is a variable, like others with similar composite spectra. 

 Practically there is a little difference, for in a. Orionis, a. Herculis, 

 and others of that type, we find well-marked dark absorption fiutings 

 of manganese, as well as line-absorption of sodium and magnesium. 

 . The manganese absorptions agree with some of the Mn fiutings seen 

 in the Bessemer flame by Marshall "Watts (' Phil. Mag.,' February, 

 1873). The absorptions are not so well developed in the Nova, for 

 the reason, perhaps, that condensation due to gravity had not taken 

 place to such a great extent, so that the heat of the stones them- 

 selves was not so great, and further because the local absorption 

 around each meteorite would be cloaked by the bright radiation of 

 the interspaces, which gives, as in comets, the maximum intensity to 

 the bright fluting, wave-length 517. In R. Geminorum the demon- 

 stration of the same meteoric constitution, but without the strong 

 absorption, is given by the fact that in that star so much of the light 

 proceeds from the vapour produced by the meteorites, and from the 

 carbon in the interspaces, that the carbon fiutings and the bright 

 lines of barium and strontium, and other substances present in 

 meteorites, are visible at the same time, exactly as they are seen in 

 the glow over a meteorite in an experimental tube, in which, as the 

 pressure is reduced, the edges alone of the carbon fiutings are visible, 

 and put on the appearance of bright lines, almost exactly resembling 

 the bright lines of the heated meteorites. 



The spectra of these two stars I give on a map (Map 3) side by side 

 with the bright fiutings of carbon and the bright fiutings of man- 

 ganese with a view of showing that, both in the temporary Nova 

 and the first magnitude star in the same constellation, many of the 

 phenomena are the same and are therefore probably produced by the 

 same cause. Some time after Dr. Copeland's original observations of 

 this star were published, it was pointed out by Duner, Vogel, and 

 others, that some of the bright parts of the spectrum observed by him 

 were really coincident with the bright parts of the spectrum of 

 a, Orionis; this, of course, is beyond question. But in addition to 



