ASTRONOMY. 



299 



Mr. Chandler, using the above-mentioned Dun-Echt observation, 

 with one made at Washington, September 23, and Cambridge, United 

 States, September 30, found that a parabolic orbit gave considerable 

 deviations in the middle place, and deduced therefore the following 

 elliptic elements. The elliptic elements obtained by Professor Planta- 

 mour, for the comet of 1843, and by M. Meyer, for that of 1880, are 

 given for comparision: 



Comet 1843. 



Comet 1880. 



Comet 1882. 



Per. pass . 

 fi 



Mean eq . 

 Log. q... 



Period . 



355° 46' 48". 4 



77 43 57 .9 



143 1 31 .2 



1880. 

 7. 8394780 

 0.999117 

 7. 82165 

 21. 875 years. 



356= 16' 43". 2 



77 53 55 .9 



143 7 46 .8 



1880. 



7. 7720095 



0. 99D467 



11. 08690 



36. 91 years. 



Sept. 17, 1880. G. M. T. 



346° 51' 58" 



71 39 3 



• 142 35 51 



1882. 



7. 943416 

 0. 997898 

 4. 17535 



8. 532 years. 



A comparision of the orbit with whatever observations were avail- 

 able seemed to Mr. Chandler to confirm the periodical nature of the 

 comet, although further observations will be necessary to fix the period 

 with precision. 



The physical appearance of the comet which, like that of 1843, and 

 unlike that of 1880, showed at first a decided nucleus, together with 

 the above intimation of a period very considerably greater than that 

 of the internal from 1830, January 27, the date of perihelion of the 

 1880 comet, suggest that perhaps the 1843 comet suffered disintegration 

 when at its nearest approach, and that the 1880 comet was a i)ortion of 

 its less condensed material, whilst the body of the comet, with the prin- 

 cipal nucleus, suffering less retardation than the separated part, has 

 taken two and a half years longer to perform a revolution. The re- 

 markable discovery made by Professor Schmidt, of Athens, on October 

 8, of a second comet only 4° S. W. of the great comet, and having the 

 same motion, would seem rather to confirm this view. 



The spectroscopic observations of the comet have only been less in- 

 teresting than the questions of its orbit and identity. M. ThoUon, who 

 examined its spectrum on September 18, with a Steinheil spectroscope, 

 having one jDrism of 60° of dense flint, in conjunction with a horizontal 

 telescope of 9 inches aperture, into which the light of the comet was 

 reflected by means of a siderostat, gives the following description of it: 



"Although working in full daylight, the spectrum of the comet was 

 very bright; its leading characteristic was the presence of the bright 

 lines of sodium. We at once saw in the field of the instrument a tolera- 

 bly distinct spectrum, due to the scattered light of our atmosphere, in 

 which the dark Fraunhofer lines could be distinguished. Upon the 

 background of this spectrum a narrow and much more brilliant contin- 

 uous spectrum, given by the nucleus of the comet, was seen clearly de- 

 tached. From the height of the spectrum we estimated the apparent 



