HERSCHEL THE DISCOVERER. 2*7 



whole, confirmed his previous result, the " apex " 

 being again situated in Hercules ; but the 

 determination of 1783 was probably the more 

 accurate of the two. 



Herschel was far in advance of his time re- 

 garding the solar motion. The two greatest 

 astronomers of the next generation, Bessel and 

 Sir John Herschel, rejected the results reached 

 by Sir William Herschel. But in 1837 Argel- 

 ander, after a profound mathematical discussion, 

 confirmed Herschel's views, and proved the solar 

 motion to be a reality. Since that date the 

 problem has been attacked by various methods 

 by Otto Struve, Gauss, Madler, Airy, Dunkin, 

 Ludwig Struve, Newcomb, Kapteyn, Campbell, 

 and others, with the result that the reality of 

 the solar motion and of the direction fixed by 

 Herschel has been proved beyond a doubt. As 

 Sir Robert Ball well remarks, mathematicians 

 have exhausted every refinement, " but only 

 to confirm the truth of that splendid theory 

 which seems to have been one of the flashes 

 of Herschel's genius." 



In his volume ' Herschel and his Work/ Mr 

 James Sime writes: "To Herschel belongs the 

 credit not merely of having suspected the revolu- 

 tion of sun around sun in the far-distant realms 

 of space, but also of actually detecting that this 



