THE SUN'S MOTION IN SPACE. 197 



The following comparison between the parallax and magnitudes 

 according to different estimates, is given, viz., 



Magnitude 123456789 

 Struve 1-00 1-80 2-76 391 5-45 773 11-55 17-40 — 

 Ristenpart 1-00 1-53 2-34 358 547 8-34 12-69 19-23 28-97 

 Gylden 1-00 131 1-77 2-47 351 509 751 11-21 16-99 



Using Gylden's hypothesis, and accepting Houzeau's values, 

 R.A. 282-°25, I. = 62-°5, for the longitude of the ascending node, 

 and inclination of the plane of the visible galaxy, the following 

 results were obtained — 



Parallax. R.A. D. 



0-"02--04 292-°2 + 52-°3 



•04 --06 285-6 47-6 



•06 --12 280-5 33-7 



These still shew the progression referred to, that is to say the 

 hypothesis of motion in the plane of the Milky-Way leads to no 

 better result. Treating again a limited number of stars of classes 

 1, 2 and 3, it was found that the results were 1 — 

 Class. Magnitude. f£ r ° s f R.A. D. Mean P.M. Mean Mag. 



1. 7-6- < 89 281-1 +22-9 0-240 8-13 



2. 5-6-7-5 199 274-8 13-0 -230 6-54 



3. 1- -5-5 106 272-4 9-4 -219 4-10 



Finally, taking all stars of Groups I. and II., according to 

 whether the angle of intersection of the P.M. with the meridians 

 of the solar apex be less or greater 90°, the results become — 



Group. 



No. of 

 Stars. 



R.A. 



D. 



Mean P.M. 



Mean Mag. 



I. 



394 



275°-3 



+ 13-8 



0-230 



6-24 



II. 



243 



275-9 



14-3 



•429 



6-70 



I. 



156 



77-3 



45-8 



•229 



6-61 



II. 



96 



88-8 



56-2 



•443 



6-71 



1 It may be incidentally remarked that the mean result of these 394 

 stars weighted merely as the number of stars is 



E.A.=275°6, D.= + 14-°3 

 which is almost identical with Group II. below, viz., 

 R.A. = 275'°9, D. = + 143. 



