36o Mr. South' s re-examination of the apparent distances 



No. XXIV. R. A. 17*^4'"; Decl. 26° 18' S. 

 36 Ophiuchi ; H. and S. 243. 

 continued, 

 the difference of declination of AC; and should A of 38 be 

 fixed, the difference of declination of A of 36, and A of 38, 

 will also be increased or diminished. By this mode of 

 observing we have two chances of detecting proper motion, 

 each of which will afford a verification of the other ; for suppose 

 the star A of S6 Ophiuchi to have a motion toward the south, 

 say at the rate of one second per annum, then will the dif- 

 ference of declination between it and the star C to the north 

 of it, be increased annually by one second ; but that which 

 increased the difference of declination between these two 

 stars, should diminish the difference of declination between 

 A of sQ, and A of 38 Ophiuchi ; and if our observations be 

 correct, the increase of difference on the one hand, should 

 be exactly equal to the decrease of it, on the other ; and vice 

 versa, should the proper motion of A of 36, carry it toward 

 the north. 



Secondly, in Right Ascension. 



Suppose the proper motion of A of 36 to be toward the 

 west annually one second, the result will be, to lessen the 

 difference of right ascension of it, and of the preceding star C, 

 and at the same time to augment the difference of right 

 ascension between A of 36, and A of 38 ; and, as before, 

 the decrease in the one instance, should be equalled by the 

 increase in the other ; and if the proper motion of A of 

 S6, take an easterly direction, it will be detected by conse- 

 quences opposite to those just described, but offering similar 

 verifications. 



