^, 



200 CELESTIAL MEASURINGS AND WEIGHINGS. 



nite and calculable proportion known beforehand ; and, 

 moreover, the longer ought to be situated in a parallel of 

 latitude, and the shorter in a circle of longitude passing 

 through the star. 



(24.) There is a star, the 6ist of Flamsteed's list, of 

 those in the Constellation Cygnus a star far, however, 

 from conspicuotis for its brightness ; being only of the 

 fifth magnitude ; but which, for a reason presently to be 

 mentioned, was suspected to be nearer than the gener- 

 ality of the stars. This star was subjected by the late 

 Professor Bessel to the examination above described 

 between the years 1834 and 1838, and the result of his 

 examination (made public by a singular coincidence a 

 few days before the announcement of Professor Hender- 

 son's discovery) w'as such as to leave no doubt of the 

 reality of its parallax, to the amount (as slightly cor- 

 rected by a further continuance of his observations) of 

 o"'35. Later astronomers,* going over the same ground, 

 wdth more perfect instruments and improved practice in 

 this very delicate process of observation, have found 

 a somewhat larger result stated by one at o"*57, and 

 by another at o"'5i so that we may take it at o"'54, 

 corresponding to somewhat less than twice the distance 

 of a Centauri ; or to 374,320 solar distances, which 

 light would require about eight years and four months 

 to travel over. 



(25.) It cannot be supposed that results like these 

 would be accepted without undergoing the most severe 

 scrutiny and receiving confirmation from further and 

 * Messrs Auwers and O. Struve. 



