lii Proceedings of the South African Philosophical Society). 



national observatories are chiefly established, which permit the 

 refinement and perfection and true progress of the science, and 

 form the material oq which the fair superstructure of Astronomy 

 of precision is based. 



In pursuance of this type of work we have now published the 

 following Star Catalogues as the result of Meridian observations 

 made since 1879 : — 



The Cape Catalogue of 1,713 Stars for the Equinox 1885 from 

 observations 1879 to 1885. 



The Cape Catalogue of 3,007 Stars for the Equinox 1890 from 

 observations 1885 to 1895 ; and there is now in the press 



The Cape Catalogue of 8,560 Stars for the Equinox 1900 from 

 observations 1896 to 1899. 



The object of the latter Catalogue is to provide points of reference 

 on the photographic plates which cover in duplicate the zone of the 

 heavens between Declinations - 40° and - 52°, that is to say the zone 

 w^hich forms the Cape share of the international Carte du Ciel. 



The stars of this Catalogue have been so selected as to secure the 

 condition that there shall be at least ten of these standard stars well 

 distributed over each of the 1,512 photographic plates which cover 

 the zone. As each star has been observed at least three times, there 

 is ample material for making a rigid determination of the constants 

 of each plate. These constants are required for converting the co- 

 ordinates of star-images as measured on the plates into the true 

 places of the stars in the sky. But I find from the discussion of the 

 proper motions of these stars a very interesting fact. The proper 

 motions of stars were hitherto supposed to be of an entirely acci- 

 dental character — that is to say, in any considerable area of the sky 

 the mean proper motions of the stars, apart from those produced by 

 motion of the sun through space, would be zero. The discussion in 

 question shows that this is not so, but ai^parcntly that the brighter 

 (or nearer) stars are revolving as a whole with respect to the fainter 

 (or more distant) stars. This opens up a great cosmical question 

 which will demand much future study, and which is now attracting 

 the attention of astronomers. 



Besides the regular and systematic publication of our own results 

 it was no less obligatory to undertake the reduction and preparation 

 for press of those observations of Maclear which had not been 

 published by Stone. 



The whole of this has now been overtaken ; the results are 

 published in two catalogues, viz. : — 



The Cape Catalogue of 4,810 Stars for the Equinox 1850 from 

 observations 1849 to 1852 ; and 



