246 On the Motion of the Svn and Solar System. 



The calculated motions of the same stars by this apex will 

 be as in the following table, and are delineated in fig. 4. 



Table VII. 



The sum of the real motions required, with the apex of 

 the solar motion above mentioned, is less in this table than 

 that in the former by 0,50343". 



In these calculations we have proceeded upon the prin- 

 ciple of obtaining the least possible quantity of real motion, 

 by way of coming at the most favourable situation of a solar 

 apex ; and have proved that the sum of the observed proper 

 motions of the six princip^J stars, amounting to 5,3334", 

 jnay be the result of a composition of two other motions ; 

 and that the real motions of these stars, if thev could be 

 reduced to their smallest possible quantities, would not ex- 

 ceed 0,95.59". 



But as I do not intend to assert that these real motions 

 can be actually brought down to the low quantities that 

 have been mentioned, it will be neces.'iary to show that the 

 vnlidity of the arguments for establishing the method I have 

 pursued will not be an'ected by that circumstance. In the 

 iirct place, then, we should consider, that although the great 

 proper motions of Arcturus, Procyon, and Sirius, are strong 

 indications of their being affected by parallax, it does not 

 follow, nor is it probable, that the apparent changes of the 

 situation of these stars should be entirely owing to solar 

 motion ; on the contrary, we may reasonably expect that 

 their own real motions will have a great share in them. 

 Next to this, it is evident that in the case of parallactic 

 motions the distance of a star from the sun is of material 

 consequence; and as this cannot he assumed at pleasure, 

 we are consequently not at liberty to make the parallactic 

 motion sp m fig. 1, equal to the line S7n of the same figure : 

 hence it ioUows, that the real motion of the star cannot be 



from 



