152 Proceedings of Philosophical Societies. [Feb. 



ASTRONOMICAL SOCIETY. 



Nov. 14, 1823. — This Society held its first meeting after the 

 late recess this evening, when a paper by G. Dollond, Esq. was 

 read, descriptive of a new instrument of his invention for mea- 

 suring vertical and horizontal angles in practical astronomy. 

 The instrument was- exhibited in the room, and consists of two 

 telescopes, two vertical divided circles, and an artificial horizon, 

 by means of which the object is seen by direct and reflected 

 vision ; and no less than 32 distinct readings may be obtained 

 of each observation, without the usual attention to levelling the 

 instrument. 



An elegant inkstand was presented for the Society's table, and 

 many other valuable presents were received. 



The honorary medals we before alluded to (Annals, N. S. vi.) 

 were officially announced from the chair this evening; viz. 

 the Society's gold medals, to Charles Babbage, Esq. for his 

 valuable invention of applying machinery to the purposes of cal- 

 culation, and to Prof. Encke for his investigations relative to the 

 comet which bears his name. The silver medals of the Society, 

 to Mr. Rumker for the re-discovery of M.Encke's comet in 1 822 ; 

 and to M. Pons for the discovery of two comets in the same 

 year, as well as for his great zeal and perseverance in cometary 

 astronomy. These medals are to be presented at the ensuing 

 anniversary of the Society in the present February. 



Dec. 12. — The papers read this evening consisted of a very 

 able and elaborate preface which had been prepared by J. F. W. 

 Herschel, Esq. the Foreign Secretary, at the request of the 

 Council, to a series of tables for calculating the places of the 

 principal fixed stars, which have been computed by order of the 

 Society ; and will be printed in the forthcoming volume of its 

 memoirs, and a supplement to a paper before read on the theory 

 of astronomical instruments, bv Benj. Gompertz, Esq. FRS.and 

 MAS. 



Jan. 9. — The papers read at the meeting of this evening were 

 as follows : 



Observations on the Comet of 1811 taken at the Havannah, 

 by Don Joseph Joachim de Ferror of Cadiz, deceased, commu- 

 nicated by the President. 



These observations were accompanied by computations of the 

 comet in an elliptic orbit, and the elements are very nearly the 

 same as those brought out by M. Argelander. 



On the Constants of Deviation occurring in the Reduction of 

 Astronomical Observations, by Benj. Gompertz, Esq. FRS. and 

 MAS. 



This paper examines the causes of deviation, and proposes 

 formulae for their more easy reduction ; it is, however, so purely 

 mathematical as not to admit of abridgment within our limits. 



On the Opposition of the Planet Mars, which will take place 



