476 Royal Astronomical Society. 



Virgo, having been previously seen with the same right ascension as 

 the constellation Andromeda. A comparison of the track in 295 

 with the paths followed by the comets in 451, 760 and 1456. will 

 sufficiently justify the inference that the observations of the year 

 295 really belong to the comet of Halley. 



Another interval of 77 years from this epoch brings us to the year 

 218, when this famous body should have visited us again ; and it is 

 an important fact that the Chinese annals mention a comet in 218, 

 which there can scarcely be a doubt was the one in question. It was 

 seen also in Europe shortly before the death of the Emperor Opilius 

 Macrinus, who was killed on the 7th of June. Dion Cassius describes 

 it as a very fearful star, and the Cliinese tell us it was intensely 

 brilliant. It passed through Auriga, Gemini, Ursa Major, into Leo, 

 but was observed first in the morning in the eastern heavens. I fix 

 the time of perihelion passage of Halley's comet on April 6, and 

 find every circumstance recorded of the comet of 218 faithfully 

 represented. 



The preceding return fell, I think, in the year 141, and a fine 

 comet is referred to that year by the Chinese historians. It was seen 

 first in Aquarius and Pegasus, in the morning sky, about March 27, 

 and about three weeks subsequently became visible in the evening, 

 traversing Taurus, Gemini, Leo, &c. The elements of Halley's 

 comet, unaltered, do not quite agree with this track and the dates 

 attributed to the various positions ; but if we suppose the following 

 orbit, depending on the observations of 1066 and 141 (as already 

 mentioned), we shall have a very fair agreement : — 



Perihelion, March 29-1. 



o / 



Longitude of perihelion 25 1 55 1 t^ . ,. , ^ , 



Ascending node 12 50 / ^^"^"°^ ^^ ^^^^ 



Inclination 17 



Least distance 72 



Motion retrograde. 



These elements have great resemblance to those of Halley's comet, 

 and it is very likely that an orbit diflFering still less might suffice to 

 produce a tolerable agreement. But few comets are recorded about 

 this year, and none of them exhibit any indications of identity with 

 Halley's, except that of 141. 



In the catalogue of Ma-tuoan-lin we find a comet in the year 65, 

 and another in Q6, either of which may possibly have been Halley's, 

 though I think the latter agrees better on the whole. It was dis- 

 covered in January in the eastern heavens ; on February 20 it had 

 the same right ascension as the star /3 in Capricornus, and advanced 

 to the south of Scorpio. These circumstances are in perfect ac- 

 cordance with the track followed by Halley's comet when the peri- 

 helion passage takes place on January 26. 



The few particulars we have respecting the comet of a.d. 65 may 

 be represented by the orbit of Halley's comet, admitting it to have 

 reached the perihelion on August 5. It is possible therefore that 



