Chapter III: The Contribution of the Moslems

Footnote 323:

Duhem, _Système_, vol. ii, 1914, pp. 146–157.

Footnote 324:

See above, pp. 98–102.

Footnote 325:

On what follows concerning Moslem knowledge of Ptolemy’s _Almagest_
see the introduction to Karl Manitius’ German translation of the
_Almagest_, 1912. See also Haskins, _Studies_, 1924, pp. 103–104.

Footnote 326:

See above, p. 96.

Footnote 327:

Al-Battānī’s _Astronomy_, Nallino’s edit., pt. i, 1903, pp. 166–167;
pt. ii, 1907, pp. 210–211; Al-Khwārizmī’s _Kitāb ṣūrat al-arḍ_,
Nallino’s edit., 1894, p. 6. Ptolemy’s _Geography_ was translated into
Arabic at least three times: (1) by Ibn Khurdādhbeh not earlier than
about 846–847 A. D., but for private use alone; (2) by Yaʿqūb ibn
Isḥāq al-Kindī, before 874 A. D.; and (3) by Thābit ibn Qurra (826–901
A. D.).

Footnote 328:

Al-Khwārizmī’s _Kitāb ṣūrat al-arḍ_ and its origins are of interest to
us in view of the fact that certain of the figures there given for
latitude and longitude found their way into the _Toledo Tables_, which
were translated into Latin and enjoyed wide use in the West during the
twelfth century and later (see above, pp. 243–244). Various figures
given in the _Kitāb ṣūrat al-arḍ_ were quoted by later Mohammedan
writers, among them the fourteenth-century geographer Abū-l-Fidā.
These formed the basis of the discussion of Al-Khwārizmī’s work in
Lelewel’s _Géographie du moyen âge_, vol. i, 1852, pp. 21–29;
epilogue, 1857, pp. 47–60. A manuscript of the _Ṣūrat al-arḍ_, the
only one in existence, was discovered by Wilhelm Spitta in Cairo in
1878 and described by him in an article entitled _Die Geographie des
Ptolemäus bei den Arabern_, 1882. Spitta’s article was completely
superseded by Nallino’s more critical study (_Al-Ḫuwârizmî e il suo
rifacimento_, 1894). Nallino shows that Lelewel’s theory, that the
_Kitāb ṣūrat al-arḍ_ is a translation of a work called _Oresmos_ by a
seventh-century Greek geographer, will not hold water. He suggested
that the work was not a direct translation from Ptolemy but was
composed to elucidate and explain a map which itself was compiled
directly from a Greek, not Greco-Syrian, version of the _Geography_.
The fact that Al-Khwārizmī’s figures in many cases diverge slightly
from those of Ptolemy may be explained by the supposition that they
were reconstructed from data given on a map, rather than copied from
the text of Ptolemy’s _Geography_. Later and more thorough
investigations into the _Kitāb ṣūrat al-arḍ_ by Hans von Mžik confirm
Nallino’s opinion that the treatise was based upon a map but show that
the map itself must have been compiled from a Syrian text.
Al-Khwārizmī’s work embodies the results of Moslem geographical
calculations which had tended to correct Ptolemy’s overestimate of the
length of the Mediterranean Sea (von Mzik, _Ptolemaeus_, 1915, pp.
152–176; idem, _Afrika_, 1916).

Footnote 329:

The _Astronomy_ contains: (1) in the preamble, a chapter describing
the world, first the earth as a whole and then the various seas; (2)
among the astronomical tables, a table of the latitudes and longitudes
of places in the _oikoumene_. The geographical chapter was edited and
translated into French by Reinaud in the introduction to his _Géogr.
d’Aboulféda_, vol. i, 1848 (pp. cclxxxiii-ccxc), and more recently
into Latin by Nallino in his great edition of Al-Battānī’s
_Astronomy_. Nallino contends that it was drawn from a much altered
version of a Greco-Syrian Ptolemy and that Lelewel and Reinaud were
mistaken in thinking that its origin was non-Ptolemaic.

Al-Battānī says that he drew on a certain _Kitāb ṣūrat al-arḍ_ for his
astronomical tables. This was not the work of the same title by
Al-Khwārizmī (see the preceding note), though its author undoubtedly
derived some of his data from Al-Khwārizmī’s _Kitāb_ as well as from
the Greco-Syrian version of Ptolemy (Al-Battānī’s _Astronomy_,
Nallino’s edit., pt. ii, 1907, pp. 209–211).

Footnote 330:

See above, pp. 97 and 244, and below, note 11.

Footnote 331:

See Haskins, _Studies_, 1924, pp. 3–19.

Footnote 332:

The standard work on Az-Zarqalī is Steinschneider, _Études sur
Zarkali_, 1881–1887, which deals almost exclusively with manuscripts,
texts, and translations.

Footnote 333:

Steinschneider, _op. cit._, in: Bollettino, vol. xx, 1887, p. 1.

Footnote 334:

The writer has been unable to find that any detailed study has been
made of the sources of the _Toledo Tables_ and of the _Canons_ of
Az-Zarqalī. Though these Spanish works in their geographical aspects
undoubtedly owe much to Al-Khwārizmī, the exact relationship between
them is an unsolved problem. As is explained in Chapter X, p. 244,
above, most of the Latin translations of the _Toledo Tables_ dating
from the twelfth century and later are accompanied by a list of
geographical coördinates obviously copied from a similar list in the
original Arabic and Hebrew texts of the _Tables_. So far as the writer
is aware no manuscripts of the original Arabic list are known.
Consequently, if this is true, we can obtain no precise information
regarding the connection between the earlier Arabic figures and those
known in the West in our period. A superficial comparison, however, of
the Latin list with the figures in Al-Khwārizmī’s _Kitāb ṣūrat al-arḍ_
suffices to show that there are many figures common to each and to
establish the general thesis that the figures of the _Toledo Tables_
are based on earlier Moslem figures, especially those of Al-Khwārizmī,
which, in turn, were derived ultimately, though with many alterations,
from Ptolemy’s _Geography_.

Footnote 335:

See above, pp. 97–98, and below, p. 400, note 45.

Footnote 336:

Amari, _Musulmani di Sicilia_, vol. ii, 1858, ch. 13.

Footnote 337:

This quotation is from the preface of Edrisi’s _Geography_, Jaubert’s
translation (under Idrīsī in the Bibliography), p. xx.

Footnote 338:

Dozy and De Goeje, _Description_, 1866 (under Idrīsī in the
Bibliography), pp. ii, iv.

Footnote 339:

1154 is the date given in Edrisi’s preface. See, however, note by G.
Pardi in: Rivista geografica italiana, vol. xxiv, Florence, 1917, pp.
380–382.

Footnote 340:

De La Roncière, _Marine française_, vol. i, 1909, p. 136.

Footnote 341:

_ibid._, pp. 136–137.

Footnote 342:

See above, p. 95.

Footnote 343:

It is uncertain whether the original tables of Al-Khwārizmī were known
as the _Little Sindhind_ or whether this title was given to another
related work by the same author. See Suter, _Astron. Tafeln_, 1914, p.
viii (under Khwārizmī, Al-, in the Bibliography), and also Nallino,
_Al-Ḫuwârizmî e il suo rifacimento_, 1894, p. 10.

Footnote 344:

Haskins, _Studies_, 1924, p. 45. This was published under the title
_Introductorium in astronomiam_ in Venice in 1506. See Duhem,
_Système_, vol. iii, 1915, p. 174, note 6. This work was also
translated by John of Seville (Haskins, _loc. cit._).

Footnote 345:

Duhem, _op. cit._, vol. ii, 1914, p. 226.

Footnote 346:

See above, pp. 14–15.

Footnote 347:

Duhem, _ibid._, p. 216.

Footnote 348:

_ibid._, pp. 218–220.

Footnote 349:

See the German translation in Friedrich Dieterici’s _Die Philosophie
der Araber im ix. und x. Jahrhundert n. Chr._, vol. v, Leipzig, 1876.
The “Brothers of Piety and Sincerity” made some noteworthy
contributions to the science of geographical meteorology, but these
were not passed on to the Western world. They understood, among other
phenomena, the warming of the atmosphere by radiation from the earth’s
surface and its connection with the angle of incidence of the sun’s
rays; the influence of mountains upon precipitation; and the origin of
springs and rivers (Hellmann, _Denkmäler_, 1904, pp. (18), 23–41).

Footnote 350:

Dieterici, _op. cit._, p. 100.

Footnote 351:

Gregorius’ edit., fol. 467 (367) (cited by Duhem, _ibid._, p. 227).

Footnote 352:

_ibid._, p. 369.

Footnote 353:

_Introductorium_, III, 4–9 (cited by Duhem, _ibid._, pp. 377–386).

Footnote 354:

Calonymos’ edit. fol. 5 (cited by Duhem, _ibid._, p. 154).

Footnote 355:

Duhem, _ibid._, p. 388, cites this chapter as: Averroes Cordubensis,
_In Aristotelis Meteora expositio media_, II, 1. This work was
published in Venice in 1488.

Footnote 356:

Moses Maimonides, the great Jewish astrologer of the twelfth century,
on the other hand, ascribed the causes of the tides wholly to the moon
(Duhem, _ibid._, p. 388).

Footnote 357:

Ibn Yūnūs, Abū-l-Fidā, and other Moslem geographers tell how, in the
time of the Caliph Al-Maʾmūn, geographers were instructed to carry out
this measurement on the plain of Sinjār, north of the Euphrates, and
also in Syria near Tadmor (Palmyra) and that their results gave 57,
56¼, 56⅔, etc., Arabic miles for a degree. For translation of text of
Ibn Yūnūs see _Notices et extraits des manuscrits de la Bibl. Natle._,
vol. vii, Paris, An XII [1803–1804], pp. 94, 96 footnote (2); for
Abū-l-Fidā see Reinaud, _Géogr. d’Aboulféda_, vol. ii, pt. i, 1848, p.
17. See also Miller, _Erdmessung_, 1919, pp. 30–36, and Schoy,
_Erdmessungen_, 1917, for other figures given by the Moslems and for a
recent critical discussion of their measurement. Al-Bīrūnī describes a
method of determining an arc of meridian by measuring the curvature of
the earth from a mountain of known height. See Schoy, _Originalstudien
aus “Al-Qânûn al-Masʿûdî,”_ 1923, pp. 69–74. See also Carra de Vaux,
_Penseurs de l’Islam_, vol ii, 1921, p. 30.

Footnote 358:

Miller, Erdmessung, 1919, p. 33.

Footnote 359:

See above, pp. 243–246. On Moslem methods of determining latitude see
Schoy, _Polhöhenbestimmung_, 1911; the same, _Über eine arabische
Methode, die geographische Breite aus der Höhe der Sonne im I.
Vertikal (“Höhe ohne Azimut”) zu bestimmen_, in: Annalen der
Hydrographie und maritimen Meteorologie, vol. xlix, Hamburg, 1921, pp.
124–133; on longitudes, see the same, _Längenbestimmung_, 1915;
_Originalstudien aus “Al-Qânûn al-Masʿûdî,”_ 1923; _Geography of the
Moslems_, 1924, pp. 265–267.

Footnote 360:

See above, p. 244.

Footnote 361:

See J. K. Wright, _Knowledge of Latitudes and Longitudes_, 1923, pp.
89–91, and especially note (1) on p. 91.

Footnote 362:

On Kang-Diz see Schoy, _Längenbestimmung_, 1915, pp. 47–48.

Footnote 363:

Reinaud, _Géogr. d’Aboulféda_, vol. i, 1848, pp. ccxxxiii-ccxlvi.
Schoy, _Längenbestimmung_, 1915, pp. 45–57, discusses the question of
the origins of the use of a central meridian for the measurement of
longitude.

Footnote 364:

See Schoy, _Geography of the Moslems_, 1924, for a general review of
Arabic geography in the Middle Ages.

Footnote 365:

Josef Marquart, _Osteuropäische und ostasiatische Streifzüge_,
Leipzig, 1903, gives much important material, with excerpts from texts
and translations, regarding Moslem descriptions of Slavic, Magyar, and
Russian peoples in the ninth and tenth centuries of our era. There is
included (_ibid._, pp. 206–270) an Arabic description of
Constantinople, of the road thence to Rome, and of Rome itself.

Footnote 366:

Marquart, _op. cit._, pp. 102, 145.

Footnote 367:

Though the great, formal Arabic geographical works were not known in
the West in the Middle Ages, legendary lore of the Moslems influenced
European legends. The story of St. Brandan, for instance, undeniably
owes much to Moslem romance. See De Goeje, _St. Brandan_, 1890.

NOTES