Imperial Institute of Trance. > 65 



New Limar Tables. 



The calculation of these two orbits, notwithstanding the 

 difficulties with which it was attended, was a mere recrea- 

 tion to M. Burckhardt, which did not hinder him from 

 putting the finishing stroke to the immense researches 

 which he had undertaken on the subject of the moon's mo- 

 tions. Six years have scarcely passed, since the Institute 

 snd the Bureau des Lnvgiltides lavished their encomiums 

 on the tables of M. Burg, the Vienna astronomer. These 

 tables, constructed on several millions of excellent observa- 

 tions, supported besides bv the analytical inquiries of Count 

 Laplace, and augmented by several new equations, have 

 been generally adopted by astrononiers, and nothing hitherto 

 has warranted the least suspicion of their accuracy. M. 

 Burckhardt's first idea therefore was not precisely to tiiake 

 new tables, but of a form more convenient for calculators. 

 Mayer had remarkecl, that he could diminish considerably 

 the number of the equations and arguments, by employing 

 only, the true place of the sun, and by correcting suc- 

 cessively the arguments by the equations already calculated. 

 This form was attended wiih inconveniences, which induced 

 M. Schulze of Berlin to re-model Mayer's tables in order 

 to bring them to the mean arguments. M. Carlini of' 

 Milan has recently announced that he has formed the pro- 

 ject of a similar transformation for the tables of M. Burg. 

 M. Burckhardt first entertained this idea, and on this oc- 

 casion he wished to ascertain if there did not exist other 

 equations which deserved to be entered in the lunar tables. 

 Formerly, when an astronomer undertook new tables for 

 any planet, he commenced ihem de novo, and risked doino- 

 them less accurately than his predecessors. By the method 

 now adopted, we are no longer exposed to these retroarade 

 movements: the moderns seek for the corrections of the 

 tables most accredited, which they comp-iie with observa- 

 tions : they equal the errors of these tables to a function 

 which comprehends the corrections of the rlemenls em- 

 ployed, an<l the new equations which they wish to intro- 

 duce. In this way they determine at once the slight cor- 

 rection* of the elements already known, and the coefficients 

 of the neglected e(]uall^n3. 



In this way M Burckhardt went to work: he betran by 

 giving to M. Burg's tables the new disposition 'which 

 brought them to the mean arguments, and comparing them 

 under this new form, not only with all the observations 

 calculated by M. Burg, but also with thousands of more 



Vol. 40. No. 171. Jidij 1812. E recent 



