24 



4. The distance of the comet from the sun when in 

 perihelion. 

 To which may be added as a further means of identification, 

 whether the direction of its motion is direct or retrograde. 



In catalogues of comets these elements are given, and when 

 any new comet comes into view, and the elements of its orbit 

 are determined from the observations made, we Ctu.. compare 

 these elements with those of older comets, and thus ascertain 

 whether it has ever been seen before. 



Bright comets have been regarded by the ancients with awe 

 and dread, and thus influenced they have fortunately left us 

 pretty reliable records of their apparitions, and from these 

 Mr. Hind was able to trace successive appearances of Halley's 

 comet — which we last saw in 1835 and '36 — as far back as 11 

 B.C., and in a.d. 65 it hung as an avenging sword over Jeru- 

 salem, then besieged by Titus. 



In like manner the splendid comet of 1680 was identified, 

 with some degree of probability, with the comets of 531 and 

 1106, and the year of Csesar's death. 



"With regard to the comet of this year I find that the longi- 

 tude of its ascending node is about 123°, and the inclination 

 to the ecliptic about 38°. It probably passed its perihelion 

 at the end of January. Its motion is direct. 



Mr. Jones, of Gawler, says he first saw what he believes to 

 be the same comet some weeks earlier. It was then — (I use 

 his own words as published in the papers) — mistaken for a 

 nebulous star about 8° east of the Nubecula Minor, and 

 that three days later the same object was 2° to the east- 

 ward, had become brighter, and had assumed an oval configura- 

 tion. I fail to identify this object with our recent visitor, 

 and must express my regret that Mr. Jones did not announce 

 his discovery of a new comet at the time. I shall be glad now 

 to receive particulars of his observations. Mr. Jones further 

 appears to think that the comet of 1880 and Eaye's comet are 

 one and the same. Now, I was fortunate enough to observe 

 Faye's comet in 1850 and 1851 at Cambridge. We were the 

 first to re-discover it on November 28, 1850, and followed it up 

 till the month of March following. It was excessively faint, 

 even through the twelve-inch Northumberland telescope, and 

 was, I think, seen at only two other observatories — Cambridge, 

 in America (where they got two observations), and at Berlin. 

 It bears no resemblance to the late comet, and has a different 

 orbit. It reaches its perihelion in November this year. 



