| From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 231 |
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Courtesy of 
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Cholgi: Maḥmūd Shāh Cholgi
Gregg DeYoung
Alternate
name
Khaljī: Maḥmūd Shāh Khaljī
Flourished probably 15th
century
Since the colophon of the Persian Zīj‐i jāmiʿ mentions his name, Cholgi
has traditionally been taken as the author/compiler of this collection of
astronomical tables. He has been identified with the ruler of Malwah, a state
in central India, from 1435 to 1469, making him, like Ulugh
Beg, both prince and mathematician. Ramsey Wright has suggested, however,
that the treatise was not written by the prince himself, but rather was dedicated
to him by the still‐anonymous author. If the prince did indeed compose
this treatise, it appears to be the only work he did in astronomy. A Persian
manuscript in the Bodleian Library (Persian Manuscript Catalog, number
270) apparently chronicles the events of his reign, but no one seems to have
yet examined it for any references to astronomical activity.
The introduction informs us that the treatise originally comprised
an introduction (muqaddima), two chapters (bāb), and a
conclusion or appendix (khātima). The last chapter and appendix
were already lost during the author's lifetime. The introduction has 36 sections
(faṣl). The first of these
sections is the best known because it was published, with facing Latin translation,
by John Greaves
in his Astronomica quaedam (London, 1652). This initial section contains
basic geometrical definitions, an elementary introduction to Islamic hayʾa
(cosmography and cosmology), and some brief explications of concepts used
in spherical astronomy. Sections 2–24 deal with topics from arithmetic and
calculations useful for spherical astronomy. Sections 25–36 describe the astrolabe
and its use. The work seems to present itself (and is usually cataloged) as
a commentary on the Zīj‐i Ilkhānī of Naṣīr al‐Dīn al‐Ṭūsī. This description seems too presumptuous.
It might better be said to represent a considerably simplified prolegomena
to Ṭūsī's work (or to mathematical
astronomy in general) rather than an explication of its contents.
The most interesting part of this introductory section (and of the
Astronomica quaedam) is the cosmographical/cosmological model building.
There is nothing original from the point of view of astronomical theory or
practice. It is essentially a simple recapitulation of the model in Ptolemy's
Planetary Hypotheses and the nested spheres described by Ibn
al‐Haytham. Although he cites the “new” results of Ṭūsī's work, Cholgi has in mind only the correction of the
rate of precession to 1° per 66 years, not Ṭūsī's new, non‐Ptolemaic astronomical models.
Selected References
De Young, G. (2004). “John Greaves' Astronomica quaedam:
Orientalism and Ptolemaic Cosmography in Seventeenth Century England.” Indian
Journal of History of Science 39: 467–510. (An introduction to Greaves
and a translation of the Astronomica quaedam into English, with explanatory
notes.)
Greaves, J. (1652). Astronomica quaedam. London. (Apparently
the printed edition is based on Oxford, Bodleian Library, Persian MS 270,
Greaves 6.)
Mercier, Raymond (1994).
“English Orientalists and Mathematical Astronomy.” In The ‘Arabick’ Interest
of the Natural Philosophers in Seventeenth‐Century England, edited
by G. A. Russell, pp. 158–214. Leiden: E. J. Brill. (Greaves and his treatise
are discussed, especially on pp. 161–164.)
Wright, R. Ramsey (1926–1927). “Über die Schrift ‘Astronomica
quaedam’ von Greaves.” Sitzungberichte der Physikalisch‐medizinischen
Sozietät zu Erlangen. 58–59: 381–385. (Outlines the basic historical context.
Followed by a short note from E. Wiedemann concerning brief extracts from
(1) Farghānī's Arabic compendium to the Almagest and (2)
ʿAlī al‐Qushjī's introduction
to the study of hayʾa.)