Cowell and Crommelin have found themselves justified in adding to this table, backwards, the years b. c. 87 (May) and 240 (May); with no identification possible for the intermediate return in June, 163 B.C., though comets are vaguely mentioned in the years 166 and 165.
We owe the observations which have made these identifications possible mainly to Chinese records, supplemented, more or less, by European monastic chroniclers of various sorts and kinds, and by a few private authors. It would be tedious to transcribe any of the originals of these, even in an abridged form; indeed, in point of fact their language is already generally so curt as to be incapable of abridgement, so a concise digest is all that will be offered to the reader and this will be often given in the language of Hind[1] and chronologically backwards.
Halley surmised that the great Comet of 1456 was identical with his, and Pingré converted Halley's suspicion into a certainty. This comet was described by the Chinese as having had a tail 60° long, and a head which at one time was round, and the size of a bull's eye, the tail being like a peacock's!
At the preceding return in 1378 the comet was observed both in Europe and China; but it does not appear to have been as bright as in 1456.
In 1301 a great comet is mentioned by nearly all the historians of the period. It was seen as far North as Iceland. It exhibited a bright and extensive tail which stretched across a considerable part of the heavens. Hind rejected the European observations of 1301, finding them to be of no good compared with the Chinese observations which proved consistent—a reversal of 20th-century preferences!
The previous apparition was for some time a matter of doubt. Hind treated as Halley's a comet which appeared in July 1223, and was regarded as the precursor of the death of
- ↑ Month. Not. R.A.S., vol. x, p. 51, Jan. 1850: The Comets, pp. 50–57.
altered where necessary to embrace the researches of Cowell and Crommelin. It should here be mentioned that some share of credit for these identifications is due to the French astronomer Laugier. (Comptes Rendus, vol. xxiii, p. 183. 1846.) Nor should the labours of Pingré and Burckhardt be forgotten in this connection.
