distances and positions of 380 double and triple stars , &c. 21 
vations of Rigel, to see how widely they differ from each 
other, and yet how exactly their mean agrees with that of 
our own, to be satisfied that, in so doing, not only no improper 
liberty is taken, but much valuable labour rescued from obli- 
vion, which would otherwise have been lost to science. In 
numerous instances, too, whole series of observations have 
been found, and their mean results inserted. These are 
generally noted by the letters MSS. annexed. 
Finally, such remarks are subjoined as comparisons of 
modern with ancient measures of the same star suggest. 
In numerous instances they confirm the changes previously 
surmised to have taken place by Sir W. Hersghel, in his pa- 
pers of 1803 and 1804. In a few they afford no such satis- 
factory confirmation. In more than one instance, they furnish 
important verifications of the proper motions assigned to 
particular stars by Maskelyne, Piazzi, and others ; while in 
some, on the other hand, the degree of permanence in the 
relative situations of the large and small stars is hardly less 
remarkable. 
After the main body of observations, we have added a list 
of a few stars less perfectly measured, or of which, from their 
uncommon difficulty, the observations are too precarious to be 
received as satisfactory. The only reason for inserting them 
is, that should there ever hereafter arise a question respect- 
ing them, any measures made with some care and with good 
instruments are better than none at all, and may become 
useful, though confessedly imperfect data. This reason is 
strengthened by the probability that their difficulty, and the 
little apparent interest they offer, will cause them to be dis- 
