Present State of Knoialedge of the Parallax of the Stars. 597 



corresponding moon- culminating observations made there and at 

 Greenwich, Cambridge, and Edinburgh, in 1834, 5, 6, and 7 — ob- 

 servations which have not before been used for the purpose, — has 

 availed himself of the occasion to enter at considerable length into 

 the practical details of the method of computing the longitude ; and 

 has given all the requisite formulae, with examples of their applica- 

 tion from the observations under discussion. 



The general result of the computations, of which a further ac- 

 count appears in the Monthly Notices for April, is that the longi- 

 tude of Madras from Greenwich is, 



h m s 



5 20 54"9 by 54 observations at Greenwich and Madras 

 53"9..56 ,, ,, Cambridge and Madras 



58-0 . . 65 „ ,, Edinburgh and Madras. 



Ephemeris and Elements of the third Comet discovered by Galle. 

 By Mr. Rumker, Superintendent of the Observatory at Hamburg. 

 Communicated by Dr. Lee. 



Approximate elements of the same comet have been received 

 from Professor Schumacher. 



It has been remarked that these elements resemble those of a 

 comet observed in China in 1097, and computed by Burckhardt ; and 

 of one which appeared in 1468, of which observations are recorded 

 by Pingre. Supposing the three appearances to have been of the 

 same comet, the periodic time is thus about 371 years. 



On the Present State of our Knowledge of the Parallax of the 

 Fixed Stars. By the Rev. R. Main. 



This paper was in part read. 



May 8. — Among the presents announced at this meeting, was 

 a 7-feet Newtonian Reflecting Telescope, the work of the late Sir 

 William Herschel, and presented by him to his sister. Miss Caroline 

 Herschel ; in whose name, and that of the President, it was now 

 presented to the Society. 



The reading of Mr. Main's paper on the Present State of our 

 Knowledge of the Parallax of the .Fixed Stars, was resumed and 

 concluded. 



This memoir was read to .the Council of the Society at their 

 meeting in January of the present year ; the object of it being a 

 review of the parallax of the Cygni, recently obtained by Professor 

 Bessel. In presenting it as a memoir, to be read before the Society, 

 the author determined to allow it to remain in its original form of 

 a report addressed to the Council ; feeling that, if it were given in 

 any other shape, his discussion of the results of eminent contem- 

 poraneous astronomers on the subject of annual parallax might 

 seem presumptuous. He recommends to the notice of astronomers 

 a very complete historical summary of astronomy, as connected 

 with this subject, by Fockins (which work was printed at Leyden 

 in 1835), entitled Commentatio Astronomica de Annuali Stellarum 

 Paralhui, which, he remarks, very materially assisted liim in the 

 prosecution of the historical part of his work. The author proposes 

 the following divisions of his report ; — 



