48. 



ON THE MEAN PLACES OF 84 FUNDAMENTAL STARS, AS DERIVED FROM 

 THE PLACES GIVEN IN THE GREENWICH CATALOGUES FOR 1840 AND 

 1845, WHEN COMPARED WITH THOSE RESULTING FROM BRADLEY'S 

 OBSERVATIONS. 



[From Appendix II. to Astronomical Observations made at the Cambridge Observatory. 



Vol. xxn. (18661869.)] 



INTRODUCTION. 



THE present Appendix contains the formulae and instructions which I 

 drew up, many years ago, for the formation of a proposed New Fundamental 

 Catalogue, to be used in the computation of the Star places given in the 

 Nautical Almanac. The proposed plan was eagerly accepted by my friend, 

 the late Lieutenant Stratford, who was then the superintendent, and my 

 instructions were ably carried out by Mr K. Farley, then the principal 

 assistant in the Nautical Almanac Office. The mean places were thus 

 calculated for the beginning of each of Bessel's so called fictitious years 

 from 1830 to 1870. The results for the years from 1857 to 1870 inclusive 

 have already appeared in the several volumes of the Nautical Almanac. It 

 has been thought desirable to collect together these results as well as 

 those for the previous years, so as to exhibit at one view a set of mean 

 places of each star, for the beginning of each year from 1830 to 1870, 

 founded on consistent elements. It should be remarked that in all these 

 calculations the actual proper motion of each star is supposed to be uniform 

 .and to take place in a fixed great circle. Hence no attempt is made 

 to take into account the variability in the observed proper motions of 





