326 



SCIENCE. 



[N. S. Vol. XVII. No. 426. 



One plate of >* Eridani was obtained in 

 the autumn of 1901, and four a year later. 

 The range of velocity so far observed is 

 from + 3 to + 26 km. per sec. 



"We regard two or three other stars with 

 spectra of the Orion type as suspicious of 

 variable radial velocities, but the number 

 of plates so far obtained is insufficient to 

 establish the variation. The proportion of 

 spectroscopic binaries, found by us in this 

 special class of stars, to the number of 

 which we have obtained three plates is 

 about 1:5. 



The Orbit of the Spectroscopic Binary >-/ 



Orionis: Walter S. Adams. 



The variation in the radial velocity of 

 ri Orionis was discovered at the Yerkes Ob- 

 servatory in December, 1901, by Professor 

 B. B. Frost and the writer. Since that 

 time twenty-eight spectrograms have been 

 secured, covering an interval of very nearly 

 a year, and in the present paper the star's 

 orbit is computed from them by the method 

 of Lehmann-Fillies. The greatest range 

 found is about 285 km., and is the largest 

 which has hitherto been discovered among 

 binaries which like this have one component 

 dark. The spectrum is of the Orion type, 

 but contains several silicon, oxygen and 

 nitrogen lines as well. 



The period used in plotting the observa- 

 tions is 7.9896 days, and the following ele- 

 ments are found: 



Velocity of system "F = -f- 35.5 km. 

 M„ = 90°41'.6 

 «; = 42° 16' 

 e = 0.016 

 ^ = 45°.059 



y=1901, December 1.821 

 asini= 15,901,000 km. 



An ephemeris is computed with these ele- 

 ments, and the greatest difference between 

 the observed and computed velocities is 

 found to be less than 3 km. 



The Masses in 85 Pegasi: George G. Com- 



STOCK. 



^5 Pegasi is a sixth magnitude star with 

 an eleventh magnitude companion distant 

 less than a second of arc. Burnliam, who 

 discovered the pair in 1878, has published 

 an orbit with a periodic time of 25.7 years. 

 The bright star of the pair has been fre- 

 quently compared with a neighboring ninth 

 magnitude star, and from a discussion of 

 these measures covering a period of fifty 

 years I find for the masses of the sixth 

 and twelfth magnitude stars the ratio, 2:3, 

 the faint star having the greater mass, al- 

 though its light is only a hundredth part 

 that of the brighter star. 



This result is directly opposed to the 

 common view that regards the fainter com- 

 ponent of a binary star as more nearly 

 extinct than its companion, because a 

 smaller mass has caused it to traverse more 

 rapidly the stages of development that lead 

 to extinction. 



Stellar Revolutions within the Galaxy r 

 Frank W. Vert. 

 Independent estimates of the parallax of 



Nova Persei give 



7r = 0".052, and 7r = 0".049, 



whence it is concluded that the distance of 

 this presumably galactic object is about 

 600,000,000,000,000 km. It is proposed to- 

 adopt this distance as a first approximation 

 to the sun's distance from the Milky "Way. 

 The first-type stars, of which the galactic 

 stream is mainly composed, probably have- 

 rather small linear velocities, and are the- 

 result of agglomerative tendencies; but 

 around the central condensations there is 

 a great sphere of stars, mostly in advanced 

 stages of development, which seems to have 

 been produced by stellar dispersal. These 

 outlying stars may have been thrown off 

 from the central condensations by explo- 

 sions of great magnitude; and if the ve- 



