ASTRONOMY. 201 



one of 18-43, which I remember well, although it vras inferior in li-nj^tb 

 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 ITind. The elements of the orbit of this comet 

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



Hiud, 1880. 



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



Long, per , .279 deg. C miu. 8 sec. 



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



Inclination 35 deg. 39 min. 8 sec. 



Per. dist ., ....0.0059390. 



Motion Retrograde. 



Comet 1843. 



Per. pass February 27. 



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



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



Inclination 35 deg. 39 min. 2 sec. 



Per. dist 0.005511. 



Motion lietrograde. 



IVIr. Hind, in communicating these results to the Astronomer Royal 

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

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

 less than thirty-seven years ? I confess I feel a difidculty in admitting 

 it, notwithstanding the above extraordinary resemblance of orbits." 

 The api^earauce of this great coinet 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 comj^uted the numerical value of 

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

 and linds it to belong to the same type of those of 1G80, 1744, 17G9. I 

 am not aware that any observations by the sjiectroscope 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 G, and its train was easily seen, and was three 

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

 of its orbit were computed by Safford, HoLETScnEK, Bigourdan. 



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

 above. 



Comet C is Faye's short-period comet. It was seen by Mr. Com^ion, 

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

 of this comet is 7.413. It was found by the aid of an ephemeris pre- 

 viously computed. 



Comet D was discovered by Dr. HARTWia, 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 



