360 Mr. South’s re-examination of the apparent distances 
No. XXIV. R. A. i7 h 4 ra ; Decl. 2 6° 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 36 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 36, 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 3 6 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 
36, take an easterly direction, it will be detected by conse- 
quences opposite to those just described, but offering similar 
verifications. 
