1825.] Royal Society. Qb 



sions. If any circumstances depending upon change of temper- 

 ature, flexure of the instrument, or other causes of error existed, 

 why, he says, should they not be general for all the stars ? Why 

 should such causes exist for a Lyrae, and not for the pole star, 

 which shows no sensible parallax? 



On the question of southern motion. Dr. Brinkley compares 

 Mr. Bessel's, Mr. Pond's, Mr. Piazzi's, and Dr. Bradley's Cata- 

 logues, and after endeavouring to prove discordance in the 

 Astronomer Royal's mode of applying the data in these Cata- 

 logues to the question, he says, " from the weight of external 

 testimony adduced, it Vvill, I think, be readily conceded to me, 

 that the southern motion does not exist, and that it must be 

 regarded as an error, belonging to one or both of the Greenwich 

 Catalogues of 1S13 and 1823." 



Such is the state of these two questions ; they are not, how- 

 ever, questions of useless controversy, nor connected with hostile 

 feelings : the two rival astronomers seem equally animated by 

 the love of truth and of justice, and have carried on their discus- 

 sions in that conciliating, amiable, and dignified manner, which 

 distinguishes the true philosopher. I cannot give a stronger 

 proof of this, than in stating that the Astronomer Royal was 

 amongst the first of the members of the Council to second and 

 applaud the proposition for the award of this day. 



After some further observations on the subject of parallax, 

 the President remarked, that it is to be regretted that no star 

 has yet been observed absolutely in the zenith, which might 

 easily be done, and in a part of the globe, for instance under the 

 equator, where almost precisely the same circumstances oftem- 

 peraturCj moisture, and pressure of the atmosphere, would exist 

 in summer and winter. An instrument fixed on granite, or an 

 aperture made in a solid stratum of rock, would destroy the pos- 

 sibility of interference from foreign causes, and reduce the pro- 

 blem to the simplest possible conditions. 



Sir Humphry Davy then congratulated the Society on the 

 great progress that is making in scientific inquiry, and the 

 means for procuring the necessary instruments, and paid a well 

 luerited tribute of respect to several of the most eminent astro- 

 nomers of the present day, and to those artists, especially 

 Troughton, Dolland, Reichenbach, and Frauenhotier, whose 

 genius and industry have brought philosophical apparatus tQ its 

 present high state of perfection. 



The President then concluded this brilliant address nearly in 

 I he following words : — 



There is no more gratifying subject for contemplation than 

 the present state and future prospects of astronomy ; and when 

 it is recollected what this science was two centuries ago, the 

 contrast aflbrds a sublime proof of the powers and resources of 

 the human mind. 



New Series, vol. ix. V 



