180 G. H. KNIBBS. 



(80) Bischof, 188J/..— In 1884 Bischof also investigated the 

 proper motion of the solar system. 1 From 480 stars, he found for 

 the coordinates of the solar-apex for the epoch 1855 



R.A. = 285-°2, D.= + 48-°5 

 Applying Airy's method, however, the result was 

 R.A. = 290-°8, D.= +43-°5 



(81) Homann, 1885. — Three extensive series of measurements 

 of the radial velocities of the stars, made respectively at Greenwich, 

 by Huggins, and by Seabroke, admitted of a determination of the 

 solar motion from those data alone. This was undertaken by 

 Homann in December 1885. 2 He found for the three series : — 



i. R.A. = 320°1, D.= +4K2, Y. = 39-3 kilometres 

 ii. 309-5, +69-7, 48-5 



iii. 278-8, +13-6, 24-5 



These results though not in perfect accord, yet shew sufficient to 

 indicate that much is to be expected of the application of the method. 



(82) Ubaghs, 1886.— In February 1886, Ubaghs submitted a 

 paper on the determination of the proper motion of our system, 

 to the Royal Academy of Sciences of Brussels. 3 Comparing the 

 results of Bradley's- catalogue with those of the Fundamental 

 Catalogues of the Astronomische Gesellschaft and with the B.A.C. 

 he obtained the following results for the epoch 1810 ? 



Mag. ISo. Stars 



R.A. 



D. 



R' 



7T 



E. 



2 56 



258-°2 



+ 30-°l 



•057" 



"•65 



•088 



3 145 



259-1 



25-9 



•045 



•40 



•112 



4 263 



265-2 



26-3 



•028 



•21 



•112 



464 4 



262-4 



26-6 









1 Untersuchungen iiber die Eigenbewegung des Sonnensystems — Bonn 

 1884. 



' z Beitrage zur Untersuchung der S tern bewegun gen und der Lichtbe- 

 wegung durch Spectral messungen — Inaugural-Dissertation, Berlin 1885. 

 Also : — Bestimmung der Bewegung des Sonnensystems durch Spectral- 

 Messungen. — Astr. Nach., Bd. cxiv.,pp. 25-26, 1886. Also The Observatory 

 Vol. ix., p 171. 



3 Determination de la direction et de la vitesse du transport dti systeme 

 solaire dans l'espace. lme partie — Bull. l'Acad. roy. Bruxelles 3° Ser.,t. xi. 

 pp. 67, 136-139, 1886; paper printed also in the Memoires de FAcad., 

 t. xlvii., 1886. 



* Quoted by L. Struve. — Mem. Acad. St. Petersb., 7me Serie, t. xxxv. 



