168 A CENTURY'S PROGRESS IN ASTRONOMY. 



Boss (born 1847), director of the Observatory 

 at Albany, New York. An investigation by 

 Newcomb fully confirmed the previous results. 

 In 1900, 1901, and 1902 Kapteyn made three 

 distinct investigations on the solar motion, and 

 still further confirmed the previous investiga- 

 tions. 



These investigations are fully confirmed by 

 the application to the question of Doppler's 

 principle of measuring radial motion. The 

 spectroscopic researches of Campbell at the 

 Lick Observatory place the solar apex very 

 near the position assigned to it by Newcomb 

 and Kapteyn. Campbell finds the solar velocity 

 to be about 12 miles a second, and Kapteyn 

 thinks a velocity of about 11 miles a second is 

 " the most probable value that can at present 

 be adopted." 



