266 COSMOS. 



mte space, this might, in process of time, occasion an appar. 

 ent change in the angular distances of the fixed stars ; and in 

 such a case, the places of the nearest stars beir g more affected 

 than of those that are very remote, their relative positions 

 might seem to alter, though the stars themselves were really 

 immoveable. And on the other hand, if our own system be at 

 rest, and any of the stars really in motion, this might likewise 

 vary their apparent positions, and the more so, the nearer they 

 are to us, or the swifter their motions are, or the more pro- 

 per the direction of the motion is, to be rendered perceptible 

 by us. Since, then, the relative places of the stars may be 

 changed from such a variety of causes, considering that 

 amazing distance at which it is certain some of them are 

 placed, it may require the observations of many ages to deter- 

 mine the laws of the apparent changes even of a single star ; 

 much more difficult, therefore, it must be to settle the laws 

 relating to all the most remarkable stars." 



After the time of Bradley, the mere possibility, and the 

 greater or less probability, of the movement of the solar system, 

 were in turn advanced in the writings of Tobias Mayer, Lam- 

 bert, and Lalande ; but William Herschel had the great merit 

 of being the first to verify the conjecture by actual observations 

 ( 1 783, 1 805, and 1806). He found (what has been confirmed, 

 and more precisely determined by many later and more accurate 

 inquiries,) that our solar system moves towards a point 

 near to the constellation of Hercules, in R. A. 260 44', and, 

 N. Decl. 26 16' (reduced to the year 1800). Argelander, 

 by a comparison of 319 stars, and with a reference to Lun- 

 dahl's investigations, found it for 1800: R. A. 257 54'- 1, 

 Decl. + 28 49'-2; for 1850, R. A. 258 23'-5, Decl. +2845''6. 

 Otto Struve (from 392 stars) made it to be for 1800: 

 ILA. 261 26'-9, Decl. +37 35'-5; for 1850, 261 52'"6, 

 Decl. 37 33'*0. According to Gauss, 8 * the point in question 



* In a letter addressed to me ; see Schuni. Astr. Nachr. % 

 no. 622, 8. 348. 



