192 HISTORY OF ASTRONOMY. 



Bessel with those of Bradley and other astronomers. 

 These motions exhibit considerable uniformity, and their 

 direction is invariably toward the south. 



Madler next examined the 12 principal stars within 

 five degrees of this group, and finds that 8 exhibit a 

 decided southern motion, while in the other 4 the motion 

 is too small to be decisive, but in no case is the motion 

 toward the north. Among thirty stars, between 5 and 

 10 degrees distant from the Pleiades, Madler finds that 

 20 are moving toward the south ; while the motion of 

 the remaining 10 is scarcely perceptible. Among 57 

 stars, between 10 and 15 degrees from the Pleiades, 16 

 are moving toward the south, while the motion of the 

 remaining 41 is scarcely perceptible. Not one moves 

 toward the north. Out of 66 stars, between 15 and 20 

 degrees from the Pleiades, 30 have a decided southern 

 motion, and 36 are undecided. Thus, out of 176 stars, 

 within 20 degrees of the Pleiades, we find 85 moving 

 toward the south, and 91 whose motion is scarcely per- 

 ceptible, but not a single case in which there is a con- 

 siderable motion toward the north. 



Madler next examined all of Bradley's stars between 

 20 and 30 degrees from the Pleiades, of which the number 

 is 175 ; of these, 78 exhibit a motion toward the south, 

 92 are uncertain, and 5 have a slow motion toward the 

 north, amounting in the most rapid case to only seven 

 seconds in a century. Such a result Professor Madler 

 considers a necessary consequence of his hypothesis. 

 Since only small real motions are to be expected in the 



