See KingD. A., “Ibn Yūnus”, in Dictionary of scientific biography, xiv (New York, 1976).
2.
On Islamic zījes see KennedyE. S., “A survey of Islamic astronomical tables”, Transactions of the American Philosophical Society, n.s.xlvi (1965), 123–77.
3.
More information on the author and his zīj is given in KingD. A., Mathematical astronomy in medieval Yemen (Publications of the American Research Center in Egypt; Malibu, California, 1982), Section II.7.
4.
Ibid., for details of this tradition.
5.
For astronomy in Egypt in the thirteenth, fourteenth, and fifteenth centuries, see KingD. A., “The astronomy of the Mamluks”, to appear in Muqarnas, ii (1983).
6.
For further details see HartnerW., “Zamān” in The encyclopaedia of Islam (1st ed., Leiden, 1913–34), reprinted (German version only) in idem, Oriens-Occidens (Hildesheim, 1968), 260–3.
7.
Wüstenfeld-Mahler'sche Vergleichungstabellen zur Muslimischen und Iranischen Zeitrechnung … (Wiesbaden, 1961) and SchrammRobert, Kalendariographische und Chronologische Tafeln (Leipzig, 1908).
8.
For details see KingD. A., “Ibn Yūnus' Very useful tables for reckoning time by the Sun”, Archive for history of exact sciences, x (1973), 343–94, pp. 345–7. Sunset, daybreak, nightfall, and other times of religious significance can be calculated for any terrestrial latitude and solar longitude by using modern computer-generated tables similar to those used by medieval Muslim astronomers (ibid., 353).
9.
TuckermanBryant, Planetary, lunar, and solar positions, 601 b.c. to a.d. 1, Memoirs of the American Philosophical Society, lvi (Philadelphia, 1962); a further volume, ibid., lix (Philadelphia, 1964) carries the ephemerides to 1649 a.d.
10.
NeugebauerPaul V., Sterntafeln von 4000 vor Chr. bis zur Gegenwart nebst Hilfsmitteln zur Berechnung von Sternpositionen (Leipzig, 1912).
11.
These terms and others are used also by YūnusIbn but are nowhere precisely defined. See LaneE. W., An Arabic-English lexicon (London, 1863; reprinted Beirut, 1968), sub asbac, shibr, and rumḥ.
