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120 vapour, and the comet" all disappeared. It seems fairly certain that this was Halley's Comet. At any rate it was immortalised in the famous Bayeux Tapestry, as will be seen from the annexed plate. [Plate XII.]

In 989 a comet was observed in China which is mentioned also by several Anglo-Saxon writers. Burckhardt, the French computer, investigated its orbit and found that the elements bore a considerable resemblance to those of Halley's Comet. The perihelion passage was found to have occurred about Sept. 12.

Halley's Comet certainly appeared in 912, but there were 2 comets in this year and Cowell and Crommelin differ from Hind in the identification, Hind selecting the earlier one and Cowell and Crommelin the later one, which appeared in the autumn.

Halley's Comet should have appeared in 837. There cer- tainly was a comet in this year, but a comparison of the European and Chinese accounts, taken literally, imply that there were 2 comets in this year, one in perihelion in February and the other in April. The latter would seem to have been a most imposing object, but in Hind's opinion it could not have been Halley's Comet. The Chinese records indeed imply that there was a third or even a fourth comet in that year, in the months of June and September, but we need not discuss this question, which probably involves some misconceptions and which does not concern us in discussing Halley's Comet.

A comet appeared in 760, which without any doubt whatever was Halley's. It is recorded in detail both by European and Chinese annalists, and the orbit has been calculated and identified by Laugier. By European writers we are told that a comet like a great beam and very brilliant was observed in the 20th year of an Emperor Constantine, first in the E. and then in the W., for about 30 days. The Chinese gave it a visibility of 2 months. Laugier calculated the perihelion to have occurred on June 11.

In 684 the Chinese record a comet observed in the W. in September and October. Hind pointed out that this statement would accord with the course of Halley's Comet when