The Rôle of Observations in Ancient and Medieval Astronomy

Graz Dated , 13 October 1597 (Ed. naz., x, 69f).

Brahe Tycho , Opera omnia, ed. Dreyer , iv (Copenhagen, 1922), 422; see Hartner W. , “Tycho Brahe et Albumasar. La question de l'autorité scientifique au début de la recherche libre en astronomie”, La science au seizième siècle (Paris, 1960), 137–50; reprinted in Hartner W. , Oriens-Occidens (Hildesheim, 1968), 496–507.

“De cometa anni 1577”, Opera omnia, iv, 387f.

“The Authenticity of Ptolemy's Parallax Data, i & ii”, Quarterly journal of the Royal Astronomical Society, xiv (1973), 367–88, and xv (1974), 9–29, and “The Authenticity of Ptolemy's Eclipse and Star Data”, ibid., xv (1974), 107–21.

“The Arabic Version of Ptolemy's Planetary Hypotheses”, Transactions of the American Philosophical Society, n.s., lvii, no. 4 (1967), 3–55.

For this section see Hartner W. , “Mediaeval Views on Cosmic Dimensions and Ptolemy's Kitāb al-Manshūrāt”, Mélanges Alexandre Koyré (Paris, 1964), i, 254–82; reprinted in Oriens-Occidens (ref. 2), 319–48.

Mas^cdic Canon, Arabic text (Hyderabad-Dn., 1955), ii, 641.

See Kennedy E. S. , A commentary upon Bārūnī's Kitāb Taḥdīd al-Amạkin (Beirut, 1973), 266.

Here and below, sexagesimal fractions.

“Mediaeval Views … “(ref. 6), 268f (Oriens-Occidens, 333f).

See ref. 5, p. 7, col. 1.

Cf. also Pedersen O. , A survey of the Almagest (Odense, 1974), 212.

Philosophical transactions, xiv (1684), 724.

Bernard here refers to a “Ms. Seld.”, which I have not verified.

Kitāb Taḥdīd nihạyat al-amākin (cf. Kennedy's commentary, see ref. 8), Arabic text, ed. Bulgakov P. (Cairo, 1964), 113f.

See Hartner W. , “The Astronomical Instruments of Cha-ma-lu-ting, their Identification, and their Relations to the Instruments of the Observatory of Marāgha”, Isis, xli (1950), 184–94; reprinted with concluding remarks in Oriens-Occidens (see ref. 2), 215–26.

For a detailed description, see Needham Joseph , Science and civilisation in China, iii (Cambridge, 1959), 294ff, espec. 298f.

The shadow line can easily be read to 1mm. For a latitude of 34° and a gnomon of 12m, one minute of arc corresponds near summer solstice to 3·5mm, and near winter solstice, to 11·5mm.

I refer to A. Sayili's important monograph on The observatory in Islam (Ankara, 1960).

For this section, cf. Hartner W. and Schramm M. , “Al-Bīrünī and the Theory of the Solar Apogee”, Scientific change, ed. by Crombie A. C. (London, 1963), 206–18.

Caussin , “Le livre de la grande table Hakémite”, in Notices et extraits des manuscrits, vii (Paris, an XII [1803/4]), 16–240.

Cf. Rome A. , “Les observations d'équinoxes de Ptolémée et le mouvement de l'apogée solaire”, Ciel et terre, lix (1943), 141–55; Petersen V. and Schmidt O. , “The Determination of the Longitude of the Apogee of the Orbit of the Sun according to Hipparchus and Ptolemy”, Centaurus, xii (1967), 73–96; and Pedersen O. , A survey of the Almagest (ref. 12), 145–9.

This method was employed in China, though only to get the day, not the hour, in the fifth century a.d. See Maspero H. , “Les instruments astronomiques des Chinois au temps des Han”, Mélanges Chinois et Bouddhiques, vi (1939), 258.

Al-Battānī Opus Astronomicum, ed. Nallino C. A. , ii (Milan, 1907), 57f.

Computed for the sake of simplicity from the Almanaque Náutico 1954 (San Fernando (Cadiz), 1953). For the accuracy of measurements carried out with Ptolemy's equatorial ring and of altitude measurements in general, I refer to Bruin E. and Bruin M. , “The Equatorial Ring” (Al-Bīrūnī Newsletter, no. 8 (Beirut, 1967)), and “Measurements in the Prime Meridian” (ibid., no. 6 (Beirut, 1967); both papers mimeographed), which contain very important experimental information.

Caussin , op. cit. (ref. 21), 232ff.

Ibid., 196.

Ibid., 56. As it stands, the passage is not clear and needs further consideration.

See ref. 20.

Hartner W. , (1) “Naṣīr al-Din al-Ṭūsī's Lunar Theory”, Physis, xi (1969), 287–304; (2) “Trepidation and Planetary Theories. Common Features in Late Islamic and Early Renaissance Astronomy”, Accademia Nazionale dei Lincei, Fondazione Alessandro Volta, Atti dei Convegni 13 (Rome, 1971), 609–29; (3) “Ptolemy, Azarquiel, Ibn al-Shāṭir, and Copernicus on Mercury. A Study of Parameters”, Archives internationales d'Histoire des Sciences, xxiv (1974), 5–25; (4) “Ptolemy's and Copernicus' Mercury Models. An Accuracy Test”, ibid., 367–69.

The reader is referred to B. R. Goldstein's article on “Theory and Observation in Medieval Astronomy”, Isis, lxiii (1972), 39–47, which, in spite of the similarity of its title, deals mainly with other problems than those treated in the present paper.