10 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



occupied, and states that in the course of this examination he 

 has fallen upon a very remarkable star of the eighth magni- 

 tude, known as No. 4203 of Argelander's Durchmusterimg, 

 in north declination 22. Concerning this star, lie remarks 

 that its spectra is the most remarkable of all the thousands 

 that he has hitherto studied, and he suggests that, possibly, 

 it will be found hereafter that this is a variable star. The 

 work on which D'Arrest appears to be engaged is evidently 

 of such a nature as will eventually greatly further our knowl- 

 edge of the constitution of the universe. AstroJi. Nach., 

 LXXXIII.,1G. 



THE SCINTILLATION OF THE STARS. 



In a memoir by Montigny, it is endeavored to show that 

 the frequency of variations of the colors of stars in scintilla- 

 tion has generally a relation to the constitution of their light 

 according to spectrum analysis. The author's observations 

 embrace sixty-six nights, in the years 1871 and 1873, and he 

 snves a table of the stars observed, arrano-in^ them according 

 to the types of their spectra as given by Secchi. The num- 

 ber of scintillations observed in one second, at the zenith dis- 

 tance of sixty degrees, is also given, as well as the magnitude 

 of the star. Montigny finds that the stars scintillating most 

 belong to the first type of spectra, or those having four spec- 

 tral lines; while the stars showing weak scintillation gener- 

 ally belong to the third group, or type of nebulous bands and 

 dark lines. The average number of scintillations in the first 

 type is eighty-six; considerably exceeding that of the third, 

 which is fifty-six. The average of the second group is sixty- 

 nine. These are the stars whose spectra resemble that of the 

 sun. . No marked connection appears between the frequency 

 of the scintillation and the briohtness of the stars. The red 

 stars scintillate less than the white ones, as first pointed out 

 by Dufour. This he explains as due to the fact that, with 

 equal distances from the zenith, the total separation of the 

 colored bundles of rays dispersed by the atmosphere, and 

 which have emanated from a white star, is greater than in 

 the case of a red star; the original rays of the white star 

 being more numerous and more exposed, so as to undergo 

 more frequent interception by the passage of aerial waves. 

 12 ^4,1873, IX., 493. 



