NOTES. x 



() p. 181. Bessel in Schumacher's Jahrbuch for 1839, S. 38 ; Arago 

 Annuaire for 1842, p. 389. 



( 29S ) p. 182. See on a Centauri, Henderson and Maclear, in the Memoirs 

 of the Astron. Soc. Vol. xi. p. 61 ; and Piazzi Smyth, in the Edinb. Trans. 

 Vol. xvi. p. 447. The proper motion of Arcturus, 2"-25 (Baily, in te 

 Memoirs of the Astr. Soc. Vol. v. p. 165), as belonging to a very bright star, 

 may be called large in comparison with that of Aldebaran 0"'185 (Madler, 

 Central sonne S. 11), and that of a Lyrse 0"'400. Among stars of the 1st 

 magnitude a Centauri, with its very large proper motion of 3"'58, forms a 

 remarkable exception. The proper motion of the binary star-system in 

 Cygnus, amounts according to Bessel (Schum. Astr. Nachr. Bd. xvi. S. 93), 

 to 5"- 123. 



( 295 ) p. 182. Schumacher's Astr. Nach. No. 455. 



(S 97 ) p. 182. The same No. 618, S. 276. D' Arrest founds the result on 

 comparisons of Lacaille (1750) with Brisbane (1825), and of Brisbane with- 

 Taylor (1835). The star 2151 Puppis has a proper motion of 7"'871, and 

 is of the 6th magnitude (Maclear in Madler's Unters. iiber die Fixstern-Sys- 

 teme, Th. ii. S. 5). 



( a8 ) p. 182. Schum. Astr. Nachr. No. 661, S. 201. 



(2") p. 183. The same, No. 514516. 



( 30 ) p. 183. Struve, Etudes d'Astr. Stellaire, Texte, p. 47, Notes, 

 p. 26, and 5157 ; Sir John Herschel, Outl. 859 and 860. 



( 301 ) p. 184. Origenes in Gronov. Thesaur. T. x. p. 271. 



( 302 ) p. 184. Laplace, Expos, du Systeme du Monde, 1824, p. 395. 

 Lambert, in his Cosmological Letters, shews a remarkable leaning to the as- 

 sumption of dark cosmical bodies of great size. 



( 303 ) p. 184. Madler, Untersuch. iiber die Fixstern-Systeme, Th. ii. 

 (1848,) S. 3, and the same Author's Astronomic, S. 416. 



( 304 ) p. 185. Compare Kosmos,Bd. iii. S. 96 and 130 (Engl.ed.p. 77 

 78, Note 149) ; Laplace, in Zach's Allg. Geogr.Ephem.Bd. iv. S.i.; Madler, 

 Astr. S. 393. 



( 305 ) p. 186. Opere di Galileo Galilei, Vol. xii. Milano, 1811, p. 206. 

 This remarkable passage, which expresses the possibility of a measurement, 

 and a project for its execution, was discovered by Arago ; see his Annuaire 

 pour 1842, p. 382. 



( 306 ) p. 187. Bessel, in Schumacher's Jahrb. fur 1839, S. 5 and 11. 



( 307 ) p. 188. Struve Astr. Stell. p. 104. 



(s 08 ) p. 188. Arago, in the Connaissance des terns pour 1834, p. 281 : 



