The Babylonian Unit of Time

Neugebauer O. , Astronomical cuneiform texts (3 vols, Princeton, 1955), i, 39.

Sachs A. J. and Hunger H. , Astronomical diaries and related texts from Babylonia (2 vols, Vienna, 1988, 1989).

It should be noted that observed angular distances between celestial bodies were almost invariably expressed by the Babylonians in terms of the kùš (cubit), which was equivalent to between about 2 and 2.5 degrees.

In his Almagest, Ptolemy often speaks of a unit known as (“equatorial time”), which is perhaps better rendered as “time degree”. This was definitely equal to 4 minutes — see Toomer G. J. , Ptolemy's Almagest (London, 1984), 23.

Stephenson F. R. and Morrison L. V. , “Long-term fluctuations in the Earth's rotation: 700 B.C. to A.D. 1990” (submitted to Philosophical transactions of the Royal Society of London, 1994).

Durations of solar eclipses are rarely recorded on the LBAT and in any case the computed duration of such an event is affected by irregularities in the Earth's rate of rotation.

Huber P. J. , Babylonian eclipse observations: 750 B.C. to 0 (unpublished manuscript, 1973).

Sachs and Hunger , op. cit. (ref. 2).

Stephenson F. R. and Fatoohi L. J. , “Lunar eclipse times recorded in Babylonian history”, Journal for the history of astronomy, xxiv (1993), 255–67.

The Shoushi li yi forms chap. 53 of the Yuanshi (“History of the Yuan Dynasty”), a work compiled c. A.D. 1370.

Beijing Observatory, Zhongguo gudai tianxiang jilu zongji (“A union table of ancient Chinese records of celestial phenomena”) (Kexue Jishi Chubanshe, Kiangxu, 1988).

Needham J. Ling Wang and Price D. J. , Heavenly clockwork (Cambridge, 1986).

Ibid.

Pingré A.-G. , Annales célestes de la dix-septième siècle, ed. by Bigourdan M. G. (Paris, 1901).

Neugebauer O. , “The water clock in Babylonian astronomy”, Isis, xxxvii (1947), 37–43. Hunger H. and Pingree D. , “MUL.APIN: An astronomical compendium in cuneiform”, Archiv fur Orientforschung, xxiv (1989).