MOVEMENTS IN THE STAR-DEPTHS. 63 



when the displacement is towards the violet end it is 

 known that the star is approaching. 



Dr. Huggins, our great spectroscopist, had success- 

 fully applied this method to the star Sirius, and he had 

 found that that star is receding from the earth at the 

 rate of upwards of twenty-five miles per second. But 

 Sirius was the only star which could then be examined 

 by this method. The light of Sirius exceeds more 

 than five times that of the next star in order of bright- 

 ness, at least of those visible in our hemisphere ; and 

 with the instrument then at Dr. Huggins' disposal (his 

 own eight-inch refractor) it was found impossible to see 

 the dark lines of any other star-spectrum with a spec- 

 troscope dispersive enough to give any measurable 

 displacement of the lines. 



But the importance of the inquiry (as well as of 

 those other spectroscopic researches in which Dr. Hug- 

 gins had been so successful) was manifest to our 

 scientific societies ; and accordingly a large sum was 

 granted by the Eoyal Society for the construction of a 

 refracting telescope, fifteen inches in aperture, to enable 

 Dr. Huggins to extend his researches to the leading 

 stars of our northern heavens. This fine instrument 

 was ready for use in the spring of this year, and before 

 many weeks had passed Dr. Huggins had obtained 

 results of surpassing interest and importance. He had 

 recognised motions of recession and approach in no less 

 than thirty stars, and had traced laws before unknown 

 in the phenomena of these stellar motions. 



One of the most striking features in the series of 



