398 



Motion of the Solar SyHem in Space, 



[April 



30m,. &c. of right ascension, and at a distance of 75© from the 

 North Pole ; and, in the second case, exhibiting the nature of the vari- 

 atio7is o( the same star in declination, but no^ its extent. If we now 

 with freedom draw a curved line through each of the above series, 

 conforming as nearly Vvith the several points as is consistent with a 

 curve line, and then measure the ordinates we obtain-^ 



Interpolated Annual Proper Motion. 



A. 



K. 





P. M. 



in 

 A. R. 





P. M. 



in 

 Dcclin. 



A. 



K. 





P. M. 



in 

 A. R. 



P. M 

 in 

 Declin 



h. 



m. 





?> 





}> 



h. 



m. 







)> 



0 



30 



+ ,0312 





,0100 



XII 



30 





,0210 



+ ,0080 



I 



30 



+ 



,0250 





,0070 



XIII 



30 





,0200 



+ ,0040 



II 



30 



+ 



,0180 





,0020 



XIV 



30 





,0190 



- ,0015 



III 



30 



+ 



,0135 



+ 



,0040 



XV 



30 





,0180 



- ,0065 



IV 



30 



+ 



,0060 



+ 



,0100 



XVI 



30 





,0158 



- ,0110 



V 



30 





,0085 



+ 



,0145 



XVII 



30 





,0115 



- ,0145 



YI 



30 





,0110 



+ 



,0180 



XVIII 



30 





,0045 



- ,0175 



VII 



30 





,0160 



+ 



,0190 



XIX 



30 



+ 



,0067 



- ,0195 



VIII 



30 





,01/5 





,0180 



XX 



30 



4- 



,0163 



- ,0195 



IX 



30 





,0190 





,0170 



XXI 



30 



+ 



,0240 



- ,0175 



X 



30 





,0200 



+ 



,0145 



XXII 



30 



+ 



,0300 



- ,0160 



XI 



30 





,0210 





,0115 



XXIII 



30 





,0320 



- ,0140 



These numbers, it will readily be admitted, have been arrived at in a, 

 legitimate way, and they are proper motions ; and, since it will not for 

 a moment be contended that they represent " true" or actual proper 

 motions of the stars themselves, we will enquire how far the supposition 

 of a motion of the solar system in space will account for these several 

 values. For this purpose, on the centre P. (fig. 2), with the chord of 

 750 , describe a circle, which divide into 24 equal parts corresponding 

 to the several points at which we have determined the proper motions; 

 •with reference to the P. M. in A. R., we find that it arrives at 0, at 

 about V and XIX hours ; wliereas, to represent the effect of motion 

 of the solar system, these points should be separated by 12 hours 

 only : let us then assume VI and XVIII to represent the zero points in 



