APPENDIX 



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To a former Paper, on the quantity of the precession of the Equi- 

 noxes, as determined by certain Stars that appear to have no 

 proper motion. By The President. 



Read May 22, 1826. 



ill!' 



Since my preceding paper, relative to tlie quantity of the pre- 

 cession of the Equinoxes as determined by certain stars that appeal- 

 to have no proper motion, was read before the Academy, additional 

 observations have been made at our Observatory, which may be con- 

 sidered as affording further information of some importance. 



Dr. Maskelyne, in order to determine with the utmost exactness 

 the apparent annual motion in right ascension of his fundamental 

 Star a Aquilae, compared its place at different periods with certain 

 of the adjacent small Stars. On the supposition that these small 

 Stars had no sensible proper motion, he was enabled to ascertain 

 the proper motion of a Aquilae. From what we now know re- 

 lative to the fixed Stars, this hypothesis appears to rest on a very 

 slight foundation. The Stars he used were of the 6th and 7th 

 magnitudes, and there are, as is well known, two Stars of the 6th 

 magnitude (1 and 2. 61 Cygni) of which the proper motions far ex- 

 ceed those of any other Stars. The proper motion of 40 a Eridani 

 only of the 5th magnitude, is next in quantity to those of the Stars of 

 Cygni, 61 Virginis of the 4. 5 mag. — 43 Comae Beren. of the 

 5 mag, 61 Draconis of the 5 mag. have all very considerable proper 



