649 



determining their errors so as to remove them by numerical correc- 

 tions, have contributed as much to the advancement of astronomi- 

 cal science as his own proper labours and discoveries. His country- 

 men adopted his methods as the models of their practice ; the pre- 

 sent state of German astronomy shows with how much advantage. 



Bessel was elected a Foreign Member of this Society in 1825. 

 He died at Konigsberg on the 17th of March 1846, after a long and 

 painful illness occasioned by an internal disease. The history of 

 his labours will occupy a large and prominent place in the history 

 of astronomy during the first half of the present century. 



The Baron de Damoiseau was one of the most distinguished 

 astronomers of the age. His most considerable work was his " Me- 

 moire sur la Theorie de la Lune," which was presented to the In- 

 stitute in 1821, but not published before 1827, when it appeared in 

 the " Memoires des Savans Etrangers." The methods which are used 

 in this important memoir are, generally speaking, the same as those 

 adopted by Laplace : the moon's true longitude being assumed as 

 the independent variable, and the final equations solved by the me- 

 thod of indeterminate coefficients ; the solutions being given in nu- 

 merical and not in literal coefficients, as in the great work of Plana 

 on the same subject. The approximations, also, are carried to a 

 greater extent than in the " Mecanique Celeste." This memoir was 

 followed by the celebrated "Tables of the Moon," which were founded 

 upon it, and which appeared in 1824 under the title " Tables de la 

 Lune, formee sur la seule Theorie de 1' Attraction et suivant la divi- 

 sion du cercle en 400 degres." They form the first, and indeed the 

 only expanded tables of the moon which are founded entirely upon 

 theory, borrowing nothing whatever from observation but the sim- 

 ple elliptic elements, the proportion of distances of the sun and moon, 

 and the masses. All preceding tables, such as Mayer's, Borg's and 

 Burckhardt's, had derived many of their coefficients empirically from 

 observation. These tables are the basis of those which are used by 

 the present Astronomer Royal in the great lunar reductions which 

 are now in progress under his superintendence. 



The Baron de Damoiseau was also the author of " Tables of the 

 Satellites of Jupiter," and of many other works and memoirs con- 

 nected with the advancement of astronomical science: he was a very 

 profound analyst, a most laborious and faithful calculator, and the 

 author of the most important advancements which the lunar theory 

 received in the period which intervened between the appearance of 

 the great works of Laplace and Plana to which I have before re- 

 ferred. 



Upon the motion of Sir Robert Harry Inglis, Bart., the thanks of 

 the Meeting were given to the President for his Address, with a re- 

 quest that he would allow it to be printed. 



The Statutes relating to the election of Council and Officers 

 having been read by the Secretary, and Major Clerke and Robert 



