378 



Notice oftfbe Periodical Comet of 1819. 



or at least be so far reduced, as to be attributable to errors in 

 the observations. There is no doubt, that, if the celestial 

 bodies moved iu a resisting medium, the effect of that resist- 

 ance would be more sensible in the motion of comets than in 

 that of the planets, as at the surface of the earth we perceive 

 that the resistance of the air has most effect upon the motion 

 of those bodies having weight, whose density is least ; and it 

 actually b known that the density of comets is incomparably 

 less than that of the planets ; but if the comet, which has 

 been the subject of consideration, is destined to exhibit to us 

 in the heavens the effects of a force, of the necessity of which 

 no other phenomenon has ever yet made us sensible, it must 

 require a great number of revolutions of that body to esta- 

 blish with any probability so delicate a point in astronomical 

 science. 



The calculations to which M. Damoiseau has devoted him- 

 self, with a zeal worthy of all commendation, have already 

 given, with a great degree of exactness, the motion of the comet 

 of 1819. 



The following are the general results which he has obtained. 



Passage to Peri- 

 helion. 



Eccen- 

 tric. 



Longi- 

 tude of 

 Perihe- 

 lion. 



Longitude 

 of Node. 



Inclina- 

 tion of 

 Orbit. 



iMean daily 

 Motion. 



Semi-ma. 

 jor axis. 



1805 Nov. 22,006 

 1819 Jan. 27,752 

 1822 May 24,494 

 1825 Sept. 17,084 

 1829 Jan. 10,86? 



0.8464567 

 0,8484517 

 (),844547Jf 

 0,8449784 

 0,8446862 



156°43' d" 



156 59 1 



157 11 29 

 157 14 30 

 157 18 35 



334°18'29' 

 334 27 36 

 334 19 32 

 334 22 8 

 334 24 15 



13°35'44" 

 13 38 33 

 13 22 25 

 13 23 29 

 13 22 34 



1073"4877 

 1076 7791 



1069 4158 



1070 08Gt 

 1069 5462 



2.218912 

 2,214388 

 2,224542 

 2,223611 

 2,224360 



In order to facilitate the discovery of the comet in 1828, 

 when it will be visible throughout all Europe, M. Damoiseau 

 has computed the following ephemeris. 



1828. Aug. 28,159 



Sept. 7,175 



17,161 



27,183 



7,191 



17,162 



27,157 



Nov. 6,173 



16,171 



Oct. 



Right 

 Ascen- 



26°35 



25 47 



23 30 



19 24 



12 57 



3 52 



352 33 



340 23 



329 1 



North- 

 ern De- 

 clina- 

 tion. 



23°17' 

 24 58 



26 29 



27 50 



28 43 

 28 36 

 26 51 

 23 13 

 18 13 



Distance of 

 the Comet 



from the 



Earth. 



Distance of 

 the Comet 

 from the 

 Sun. 



Intensi 

 ty of 

 Liaht. 



1,487 

 1,276 

 1,089 

 0,920 

 0,774 

 0,658 

 0,574 

 0,521 

 0,494 



2,175 

 2,073 

 1,967 

 1,855 

 1,737 

 1,614 

 1,483 

 1,345 

 1,198 



0,096 

 0,143 

 0,218 

 0,344 

 0,552 

 0,886 

 1,380 

 2,033 

 2,851 



