A. MATHEMATICS AND ASTRONOMY. 9 



one hundred and eighty-two years; the inclination of the 

 orbit being 47.5 degrees, and its eccentricity 0.5. The prob- 

 able errors of the measurements of the distance of the stars 

 is scarcely one tenth of a second. According to the ephem- 

 eris published at the conclusion of the work of Venogradski, 

 the relative movement of these stars is at present at its max- 

 imum. Journal of the Imperial University at JSjasan, XLL, 

 311. 



SPECTKA OF THE FAINT STAES. 



Yogel states that for some time past he has been almost 

 exclusively occupied with the spectroscopic investigation of 

 faint stars. Among these are some that are distinguished by 

 having spectra which are sharply defined at the violet side, 

 but on the red side are broken up into gradually diminishing 

 bands. These are generally red stars. By a somewhat care- 

 ful study of these spectra it seems to him undoubted that 

 their discontinuity is only apparent, being brought about 

 by dark bands of absorption, which, as we must assume, are 

 the consequence of the absorption of the rays of light by the 

 atmospheres surrounding these stars. The only rational 

 classification of star spectra is, according to him, into the 

 following three classes: 1. Stars whose temperature is such 

 that the metallic vapors contained in their atmospheres can 

 exert only a very slight absorptive effect. 2. Stars whose 

 atmospheres, as in the case of our sun, are distinguished by 

 powerful absorption due to vaporized metals. 3. Stars whose 

 temperature is so lowered that the materials which compose 

 their atmospheres can combine together. In the latter class 

 Vogel embraces both the third and fourth types of spectra 

 established by Secchi. Astronom. Nachrichten, LXXXIY., 

 115. 



ON THE SCINTILLATION OF THE STAES. 



Montigny has lately presented to the Royal Academy of 

 Brussels a continuation of his researches on the scintillation 

 of the stars. In this work he has studied not only the 

 number of bands in the spectra of the stars, but also their 

 growth, and especially the obscurity of the lines and zones 

 which characterize the bands. Making use of the obser- 

 vations of Secchi, he thinks he has been able to show with 



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