moving in Eccentric and Inclined Orbits. 89 



due to the elliptic motion ; but hereafter it may be desirable 

 to reconstruct the tables of the elementary quantities for each 

 of the planets, retaining some of the principal inequalities due 

 to the disturbing force. 



Pingre, in his work On comets rtiariy years since, gave a list 

 of comets, with their elements. At that time, however, the 

 method of finding the orbit, or even the distance of a comet, 

 was understood by so few persons, that, from that and other 

 causes, the numbers contained in that table may not be accu- 

 rate: many other comets have been discovered since, and such 

 a table brought Up to the present tittle appears tO be an impor- 

 tant desideratum in astronomy. 



Mr. Hind has kindly favoured me with the following list of 

 comets which have been made out to be periodic: — 



Elements of Halley's comet, by Westphalen, for 1835. Ast. 

 Nach.^ No. 588. 



^=•96739 7r = 304° 31' 32"-19 v = 55° 9' 59"'S^ 

 i=\T ^b' 5"'\S a=17'9879i Retrograde. 



Elements of Encke's comet by Encke, for 1829. Ast. Nac/i., 

 No. 489. 



f =-84462 ff=157° 17' 53"-35 v = BW 29' 3i"*62 



i = 1 3° 20' 34"'49 a = 2-22394 Direct. 

 Elements ofBiela's comet, 1846j by Prof. Plantamour. Ast. 

 Nach., No. 584. 



^ = •75700 7r=109° 2' 20"-10 v = 245° 54' 38"-8 



»=12° 34' 53"-47 a = 3-52452 Direct. 

 Elements of the comet of Faye, by M. Le Verrier, for 1844, 

 omitting the terms multiplied by jw,". Ast. Nach., No. 541. 

 €='55596 7r = 49° 34' 19"-39 v = 209° 29' 19"'26 



1 = 11° 22° 31"-40 a = 3-81179 Direct. 

 Elements of DeVico's first comet,byDr.Brunnow, for 1844. 

 Ast. Nack., No. 563. 



^=•61765 7r = 342° SO' 49"-64 v = 63° 49' 0"-l 1 



« = 2° 54' 50"-33 « = 3- 10295 Direct. 

 Elements of Brorsen's first comet, byDr.Brunnow,forl846. 

 Ast. Nach., No. 557. 



^ = •79362 7r=116° 28' 34" i/= 102° 39' 36"'3 



» = 30° 55' 6"-6 a = 3-1502l Direct. 

 The following are the elements of the comet of Encke for 

 1829 used by M. Hansen : Additions a la Conn, des Temps, 

 1847, p. 54. 



^ = •844676 ' *f=157° 18' 24"'6 v^334° 29' 28"-8 

 »=i3° 20' 40"-2 a = 2-21997. 

 Ast. Nac/i.y No. 5^1. 



