Ixii Proceedings of the South African Philosophical Society. 



Eesults fok PaRx\llax of Stars having Laege Peoper 



Motions. 



[Arranged in Order of the Amount of Proper Motion.) 



Name of Star. 



Z. C. V'\ 243 



Lacaille 9352 



€ Indi 



02 Eridani ... 

 f Erandi 4*3 



/3Hydri 



Z, Tucanae ... 



P. XIV'^ 212 



rCeti 



Lacaille 2957 



Magni- 

 tude. 



8-5 

 7-1 



4-8 



(A 

 "IB 



6-0 



Observer. 



de Sitter 



de Sitter 



Gill 



Gill 



Elkin 



Gill 



Elkin 



Gill 



Elkin 



de Sitter 



de Sitter 

 de Sitter 



Refer- 



ence to 



Publica- 



tion. 



§ 16* 



§16t 



p. 



153 



p. 



129 



P- 



138 



p. 



160 



p. 



179 



^ 



10 



P- 



172 



§ 



^M 



§ 



14 



§ 



17 



Parallax and its 

 Probable Error. 



0-319 ± 

 0-338 ± 

 0-283 + 

 0-286 + 

 0-170 + 

 0-166 + 

 0-149 + 

 0-134 + 

 0-138 + 

 AO-162 + 

 B0173 + 

 0-310 + 

 064 -f 



0027 ) 



0020 )" 



0-016 



0011! 



0032 1 



0018 



0-017 



0-007 



0027 



0011] 



0-012 [ 



012 



0-024 



Adopted Paral- 

 lax and Pro- 

 bable Error. 



0-312 



0-283 



0-273 



0-166 

 0-149 

 0-134 

 0-138 



± 0-016 



± 0016 



+ 0-040 



+ 0-018 

 + 0-017 

 + 0-007 

 ± 0-027 



0-167 + 0-001 



0-310 

 0-064 



+ 0-012 

 + 0-024 



Time does not permit me to enter into detail as to the conclusions 

 to be drawn from these observations, but reference may be made to 

 the original work (Annals of the Cape Observatory, vol. viii., part 2, 

 pp. 140B to 144B). 



The following general conclusions may, however, be quoted : — 



1. The absolute amount of light radiated by a single star varies in 

 he 22 stars observe'd from about 10,000 times to less than y-J-^ part 



of that given off by our sun, so that indeed " one star differeth from 

 another star in glory." 



2. The absolute velocities at right angles to the line of sight vary 

 for the 22 stars from 2|- to 70 miles per second, — velocities which are 

 of the same order of magnitude as the velocities in the line of sight 

 determined by spectroscopic methods. 



3. The average parallax of a star of the first magnitude is y\y of a 

 second of arc. 



4. The sun, if placed at the average distance of the first magnitude 

 stars, would appear to us as a star of the fifth magnitude. 



* Parallax determined by observation of distances from a pair of stars situated 

 nearly in the major axis of the parallactic ellipse. 



t Parallax determined by observations of position angle of a pair of stars situated 

 nearly in the minor axis of the parallactic ellipse. 



