ASTRONOMY. 201 



one of 1843, which I remember well, although it was inferior in length 

 and brilliancy to that famous comet." February 4 the head of the comet 

 was 3 minutes of arc in diameter, as reported by Dr. Gould, who also 

 computed the elements of its orbit and found them to agree well with 

 those computed by Hind. The elements of the orbit of this comet 

 agreed very closely with the one of 1843. They are compared below: 



Hiud, 18.^0. 



Per. pass Jaiuiary 27, 0,027, G. M. T. 



Long, per 279 deg. G min. 8 sec. 



Long, node 4 deg. 1 min. 9 sec. 



Inclination 35 deg. 39 min. 8 sec. 



Per. dist 0.0059390. 



"Motion - - Eetrograde. 



Comet 1843. 



Per. pass February 27. 



Long, per 278 deg. 35 min. 1 sec. 



Long, node 1 deg. 20 min. C sec. 



Inclination 35 deg". 39 min. 2 sec. 



Per. dist - 0.005511. 



Motion Retrograde. 



Mr. nrs'D, in communicating these results to the Astronomer Royal 

 of England, says : ''Can it be possible that there is such a comet in the 

 system almost grazing' the Sun's surface, in perihelion, and revolving in 

 less than thirty-seven years ! I confess I feel a difficulty in admitting 

 it, notwithstanding- the above extraordinary resemblance of orbits." 

 The appearance of this great comet has again revived the discussions 

 of a resisting medium in space. Prof. Oppolzee, of Vienna, has pub- 

 lished recently two important papers on this theme. Tn. Bredichin, 

 of Moscow Observatory, Russia, has computed the numerical yalne of 

 the repulsive force necessary to produce the enormous tail of this comet, 

 and finds it to belong to the same type of those of 1G80, 1744, 1709. I 

 am not aware that any observations by the spectroscope were had dur- 

 ing the late appearance of this comet. 



Comet B was discovered by J. M. Schaeberle, assistant at the Ann 

 Arbor Observatory, April C, and its train was easily seen, and was three 

 minutes in length. On the IGth it was brighter and larger. Elements 

 of its orbit were computed by Sapfoed, IIOLETScnEK, Bigoukdan. 



Marten^'s elements of this comet are in close agreement with the 

 above. 



Comet C is Faye's short-period comet. It was seen by 3Ir. CoM:\rox, 

 of England, August 2. It was then extremely faint. The periodic time 

 of this comet is 7.413. It was found by the aid of an ephemcris i)re- 

 viously computed. 



Comet D was discovered by Dr. Hartwig, at Strassburg, September 

 20, and also independently announced by Prof. Harrington, of Ann 

 Arbor, September 30. It was a bright comet, j ust visible to the naked 



