Proceedings of the British Association. 389 
particular day to be designated by the London Council. The Rey. J. 
Peacock, Dean of Ely, was elected President of the next meeting. 
Section A. Mathematical and Physical Science. 
Rey. Dr. Robinson presented a Report, by Mr. Baily, from the 
Committee appointed to prepare the British Association Catalogue of 
Stars, from which it appeared that the reduction was complete. .He 
proceeded to explain the value of this catalogue by stating, that among 
___ the heavenly bodies the stars are generally considered as motionless, 
and were used as points of comparison for their more erratic compan- 
ions. In this respect, an accurate determination of their places is of 
high importance ; but it becomes still more interesting from the fact, 
that we know many of them to be in motion, so that it is difficult to find 
one absolutely fixed, and the research of their proper motions becomes 
matter of great interest. This is effected by comparing their places 
observed now, with those accurately. determined at a former epoch. 
To do this, is not so simple as might at first sight appear. In the first 
place, we do not sce the star in its true place; the motion of light 
makes it to be observed in advance of that, as the earth moves. Sec- 
ondly, it is referred to the pole or equinox: these points are not fixed 
in space; the one is influenced by the action of the sun and moon—the 
of the stars’ places, so that already they require an alteration. 
advantages of this work were such, that the Association thought no 
greater service could be rendered to astronomy than the extension of 
Mr. Baily’s catalogue. It now. ntains nearly 10,000 stars, and the 
Secular changes of the cons ‘are given with them. Besides, in 
the places of the stars there is an important improvement; the places 
in the former catalogue were derived from a comparison of those 
given by Bradley for 1745, and Piazzi for 1800: whatever error was 
in either of these, was multiplied by the mode of computation when 
brought up to 1830; but this fault was, in the present instance, correcte . 
wat 
