The history of Comet Halley

Historical records of Comet Halley apparitions, starting from the 240 BC apparition observed by the Chinese, are presented, complete with ephemerides for each known apparition. The right ascension and declination are given for each ephemeris date. Consideration is given to the theories used to predict future perihelion passage times and to the methods for identifying early Comet Halley apparitions. In addition, observations related to the physical properties and chemical constituents of Comet Halley are described, with particular emphasis on the data of the 1910 apparition.