1G6 SCIENTIFIC RECORD FOR 1884. 



Airy resigned on the 15th of August, 1881. In his report, alhidetl to 

 above, Mr. Christie stated that the next great catalogue of stars formed 

 from the Greenwich observations would not be commenced until after 

 the end of next year, as it wa ; intended to make it embrace, like the 

 preceding, the stellar work of nine years, ending with that of 1885, as 

 the last included the observations of 1876, 



New catalogues of stars. — The Armagh Observatory is preparing for 

 the press a second Armagh catalogue of about 3,000 stars, most of which 

 have been observed from three to five times with the mural circle. 



The Washburn Observatory will print in its vol. iii, now in press, a 

 catalogue of 1,001 southern stars, observed by Professor Tacchiui in 

 1807, '68, '69, and reduced by Eev. Father Hagen, S. J., and Professor 

 Holden. 



Catalogue o/ 6,000 stars. — Professor Schering writes that the Gottin- 

 gen catalogue of 6,000 stars is in process of preparation for printing. 

 For account of it see Gottinger Nachrichten, 1864, July 13. 



PARALLAX OF STARS. 



Parallax-hunting at Dunsink.* — For some years past Professor Ball 

 has employed the south refractor of the Dunsink Observatory in mak- 

 ing a systematic Search for stars with a large annual parallax. The 

 third part of the Observations contains the results of measures of 42 

 objects selected for this purpose, and the volume now before us contains 

 the observations of 368 additional objects. 



In making out a working list of stars suitable for examination. Pro- 

 fessor Ball has been guided by various considerations. Of course stars 

 with large proper motion would be naturally included, though the pre- 

 sumi)tion of nearness founded on great proper motion can hardly be 

 said to be justified by the results of observation. Many red stars and 

 variable stars have been put on the working list. It has been sug- 

 gested by Mr. Stoney that some of the former may owe their color to 

 being very small, and therefore very close to us. There is also reason 

 to believe that some of the variable stars are really very small, and that 

 therefore, as we see them, they must becomparativelj' near us. 



Several other stars have also been included, which were chosen on 

 different grounds. 



In the reconnoitering observations carried out by Professor Ball every 

 object is observed twice. The first observation is made when the star 

 is at one of the extremities of the major axis of the parallax-ellipse, the 

 second observation is made after an interval of six mouths, when the 

 star has moved to that part of the parallax-ellipse which is at the other 

 extremity of the major axis. The observation consists in the measure- 

 ment of the distance and position angle of the object under examination 



* Astronomical Observations and Researches made at Dunsink. Fifth part, Dublin, 



1884. 



