28 A CENTURY'S PROGRESS IN ASTRONOMY. 



was going on among the stars." Throughout his 

 career double stars were favourite objects of 

 observation. The study of double stars was com- 

 menced by Herschel while a musician in Bath. 

 Before his day, of course, double stars had been 

 discovered and studied, but it was believed that 

 the proximity of two stars was merely an optical 

 accident, the brighter star being much nearer to 

 us than the other. Herschel, at first sharing the 

 general view, observed double stars in the hope 

 of measuring their relative parallaxes ; assuming 

 one star to be much farther away from the Solar 

 System than another, he attempted to measure 

 the parallactic displacement of the brighter star 

 relatively to the position of the fainter. " This," 

 he afterwards wrote, "introduced a new series 

 of observations. I resolved to examine every 

 star in the heavens with the utmost attention, 

 that I might fix my observations upon those that 

 would best answer my end. I took some pains 

 to find out what double stars had been recorded 

 by astronomers ; but my situation permitted me 

 not to consult extensive libraries, nor, indeed, 

 was it very material ; for as I intended to view 

 the heavens myself, Nature, that great volume, 

 appeared to me to contain the best catalogue." 



Herschel, on January 10, 1782, submitted to 

 the Eoyal Society a catalogue of 269 double 



