Adronomical Society. ie^ 



May 3. — A paper was read on the construction of pine 

 pits worked by steam. By Mr. William M'^Murtrie. 



May 1 7. — The following papers were read : Description of 

 a grape-house adapted for early forcing, by Mr. A. Wilson. 

 — Description of American fruits, of which trees have been 

 transmitted to the garden of the Horticultural Society of Lon- 

 don, by Mr. Michael Floy of New York. — On the cultivation 

 of strawberries, by the President. 



ASTRONOMICAL SOCIETY OF LONDON. 



June 10. — The reading of Mr. F. Baily's Introduction to his 

 new Tables for determining the apparent places of about 3000 

 fixed stars was resumed and completed. This copious intro- 

 duction commences with a historic sketch of the most important 

 tables which have hitherto been published for similar purposes ; 

 none of which, however, are so extensive as the tables to which 

 the present paper is introductory. They comprehend, first, 

 all stars, not less than Xhejifth magnitude, wherever situated ; 

 secondly, all the stars, not less than the sixth magnitude, si- 

 tuated within 30° of the equator ; thirdly, all the stars, not less 

 than \.\\Q.seve7ith magnitude, situated within 10° oiihe ecliptic. 



After a few general observations, Mr. Baily speaks, in suc- 

 cession, of the distinct topics of aberration, a7inual jnecession, 

 and yititation ; exhibiting the analytical formulae which have 

 been proposed for the computation of their respective values 

 at any time (past, present, or future) ; assigning the reasons 

 for the adoption of those values of the consta7its which he has 

 preferred ; and so transforming the several formulae, as to fa- 

 cilitate and effect their reduction into one class, of comparative 

 simi^licity, which forms the basis of the tables themselves. 

 Thus the total corrections for right ascension and declination 

 respectively, assume the forms 



A«=Aa + Bi + Cc + D</ 



A 8 = A a' + B ^>' + C c' + D i' 



where the quantities denoted by o, h, c, d, and the accentuated 

 a', b', c', d% are constant for each star, while the quantities 

 A, B, C, D, are common to every star. The quantities A, B, 

 are rendered equally constant for all the stars by the assump- 

 tion of a fictitious year, commencing at that moment when the 

 sun's mean longitude at Greenwich at mean noon on Jan. 1 is 

 281°; which is, theretorc, assumed as tho tabular date ; and 

 the mode of adopting it to the current date is explained. 



The autlior then explains the arrangement and use of the 

 tables. The general catalogue of the stars is arranged in the 

 order of the right ascensions, and reduced to Jan. 1, 1830. The 



left 



