| From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, pp. 629-630 |
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Khāzinī: Abū
al‐Fatḥ
ʿAbd al‐Raḥmān al‐Khāzinī (Abū Manṣūr
ʿAbd al‐Raḥmān, ʿAbd al‐Raḥmān Manṣūr)
Mohammed Abattouy
Flourished Marw, (Merv
near Mary, Turkmenistan), first half of the 12th century
Khāzinī
was known for scientific activity in the fields of astronomy, mechanics, and
scientific instruments. A slave of Greek origin in his youth, he later converted
to Islam and received a distinguished scientific education. He had a reputation
for asceticism, devotion, and piety. Khāzinī worked in the court
of the Saljūq ruler Sanjar ibn Malik‐Shāh (reigned: 1118–1157),
and dedicated two of his most important writings to him: al‐Zīj
al‐Sanjarī, an astronomical handbook with tables for Sanjar,
and his encyclopedic Kitāb mīzān al‐ḥikma, a major work on mechanical
knowledge, specific gravity, and the like. His other known works include a
treatise on astronomical instruments (Risāla fī al‐ālāt)
and a text on a self‐rotating sphere (Maqāla fī ittikhādh
kura tadūru bi‐dhātihā).
Khāzinī's
main astronomical work is the Zīj al‐muʿtabar
al‐sanjarī al‐sulṭānī, a lengthy
astronomical handbook with tables, dedicated to Sultan Sanjar and compiled
after 1118, in the aftermath of the work done reforming the solar calendar
(the “Jalālī calendar”). It is preserved in two incomplete manuscript
copies (British Library MS Or 6669 and Vatican Library MS Ar 761), and in
a revised abridgment called Wajīz al‐zīj al‐muʿtabar
al‐sulṭānī,
made by Khāzinī himself in 1130/1131. This version was translated
into Greek in the late 1290s by Gregory Chioniades,
an Orthodox bishop, upon his return to Constantinople from Tabrīz and
then utilized by Byzantine scholars such as George Chrysococces (in Trebizond,
circa 1335–1346) and Theodore Meliteniotes (in Constantinople,
circa 1360–1388). It became a basis for the revival of astronomy then
taking place in the Byzantine Empire. Since the two extant manuscripts of
Khāzinī's Zīj lack several parts, the existence of the
Wajīz is very helpful for the recovery of some of the missing
material, although the canons and the tables contained within it have both
been drastically revised; for example, the original Zīj contains
145 tables, whereas the Wajīz has only 45.
Among
other things, al‐Zīj al‐sanjarī includes numerous
tables related to chronology and calendars as well as various tables for calculating
holidays and fasting, material related to the theory of Indian cycles, important
developments in the theory of planetary visibility, and an elaborate set of
eclipse tables. The section on visibility tabulates the arcs of visibility
for the five planets as well as those for the Moon, and it also presents differences
according to climes.
Khāzinī
undoubtedly made a certain number of astronomical observations, though they
seem to be limited in number. Quṭb
al‐Dīn al‐Shirāzī implied that Khāzinī
must have had technical competence and access to good instruments since his
determination of the obliquity was carefully made. In the introduction to
his Zīj, Khāzinī describes several astronomical instruments
and observational techniques, and he asserts in the canons that he bases his
astronomy on observations and sound theory. Further, he states at the beginning
of the Wajīz that he compared, observed, and calculated positions
for all the planets as well as for the Sun and Moon, at conjunctions and eclipses.
Khāzinī
was familiar with the astronomy of his predecessors, especially Bīrūnī,
Thābit ibn Qurra, and Battānī.
His Zīj seems to be influenced by their work in addition to his
own observations. Throughout his Zīj, he reports the methods and
conclusions of Thābit and Battānī. For instance, for predicting
the crescent visibility, Khāzinī proposes a sophisticated mathematical
method that can be traced back to Thābit's Fī Ḥisāb ruʾyat al‐ahilla.
Another
astronomical work by Khāzinī is his treatise on astronomical instruments.
The text, a short work in 17 folios, is composed of seven parts, each devoted
to a different instrument: a triquetrum, or parallactic ruler, a diopter for
measuring apparent diameters, an instrument in the shape of a triangle, a
quadrant (but called a suds or sextant), an instrument involving reflection,
an astrolabe, and devices for aiding the naked eye. All the instruments in
this text are treated in a general way, and there is no reference to any special
observatory.
Khāzinī's
text on The Self‐Rotating Sphere demonstrates his interest in
connecting astronomy and applied mechanics. This text, probably the earliest
of his extant works, describes a celestial globe that works with weights.
An instrument, in the shape of a solid sphere and marked with the stars and
the standard celestial circles, is suspended halfway within a box. The sphere
is mounted so as to rotate once a day propelled by a weight falling from a
leaking reservoir of sand. This automated celestial instrument may be used
to find arcs of importance in spherical astronomy.
Selected References
Al‐Bayhaqī,
ʿAlī
ibn Zayd (1988). Tārīkh ḥukamāʾ al‐islām.
Damascus. (Biographical account.)
Hall, Robert E. (1973).
“Al‐Khāzinī.” In Dictionary of Scientific Biography,
edited by Charles Coulston Gillispie. Vol. 7, pp. 335–351. New York: Charles
Scribner's Sons.
Kennedy, E. S. (1956).
“A Survey of Islamic Astronomical Tables.” Transactions of the American
Philosophical Society, n.s., 46, pt. 2: 121–177. (Reprint, Philadelphia:
American Philosophical Society, 1989.)
King, David A. (1999). World‐Maps for Finding the Direction
and Distance to Mecca. Leiden: E. J. Brill.
Lorch, Richard (1980). “Al‐Khāzinī's Sphere
That Rotates by Itself.” Journal for the History of Arabic Science
4: 287–329.
Pingree, David (1999). “A Preliminary Assessment of the Problems
of Editing the Zīj al‐Sanjarī of al‐Khāzinī.”
In Editing Islamic Manuscripts on Science, edited by Yusuf Ibish, pp.
105–113. London: Al‐Furqān Islamic Heritage Foundation.
Sayılı, A. (1956). “Al‐Khāzinī's Treatise
on Astronomical Instruments.” Ankara Üniversitesi Dil ve Tarih‐Coğrafya
Fakültesi Dergisi 14: 15–19.