[ASTRONOMY - MATHEMATICS - ARABIC MANUSCRIPT: JAYB & MUQANTARÂT; SINUS & ALMUCANTAR QUADRANT] Hadhâ risâle-i rüb'u mukantarât, Hadhâ risâle-i cenûb taraf, Hadha mukharrar latashich al-shaat fî taraf al-cayb min al-rub'u' mu'âl-ihtizâr.

SIBTU'L-MARDINÎ [BADR AL-DÎN MUHAMMAD B. MUHAMMAD B. AHMAD AL-MARDÎNÎ], (Egyptian mathematics and astronomy scholar), (1423-1501)., N.d. [probably Constantinople], [ca. 1830].

Original manuscript without binding. 12mo. (16 x 11 cm). In Arabic. [40] p., drawings, and tables. Marginal texts additionally. A linear wormhole on the bottom from beginning to the end, the thread in the spine is broken hence two separate parts. Otherwise a good copy.

Rare manuscript compiled from works related to astronomical instruments, written by probably Sibtu'l-Mardînî copied anonymously in the early 19th century on a paper with 'ahar' with four marginal drawings and tables.

The copier of this manuscript is not described. An 'Ebced' notes on the last blank page. The manuscript starts with a calendar in the Islamic system which is prepared with red and black inks and annotated info around the table. The first part includes how to use an almucantar, directions on the sphere, location of the stars in the sky. On the last two pages, the author describes the preparation of an almucantar. The second part is titled "Hadhâ risâle-i cenûb tarafi" [i.e. Tractate on the South direction], and the third and last part titled " Hadhâ risâle-i cenûb taraf, Hadha mukharrar latashich al-shaat fî taraf al-cayb min al-rub'u' mu'âl-ihtizâr", includes some 'sinus mathematics' with two impressive tables on the opposite page.

Sibt al-Maridini, the full name Muhammad ibn Muhammad ibn Ahmad ibn Muhammad ibn al-Ghazal (1423-1493), was an Egyptian-born astronomer and mathematician. His father came from Damascus. The word "Sibt al-Maridini" means "the son of Al-Mardini's daughter". His maternal grandfather, Abdullah al-Mardini, was a reputed astronomer of the eighth century AH. He was a disciple of the astronomer Ibn al-Majdi (d. 850/1506). Sibt al-Mardini taught mathematics and astronomy in the Great Mosque of al-Azhar, Cairo. He was also a timekeeper (muwaqqit) of the mosque. He wrote no fewer than fifty treatises in astronomy (sine quadrants, sundials, astronomical tables, and prayer times) and wrote at least twenty-three mathematics textbooks. Al-Sakhawy counted two hundred books that were written by Sibt al-Mardini, on Islamic law, astronomy, and mathematics. Libraries that specialize in ancient manuscripts, all over the world, have transcripts of his works. Sibt al-Mardini's declared that "the opinion of the muezzins (those who call people to prayer) is less correct than that of the legal scholars and it is the latter that should be used as the basis for the determination of prayer time". (Wikipedia).

Sibṭ al-Māridīnī was a prolific author of astronomical texts, which were still being used and studied into the 19th century. Little is known with certainty about his life. It is thought that he grew up in Damascus, where his maternal grandfather, Abd Allâh ibn Khalîl ibn Yûsuf Jamâl al-Dîn al-Mâridînî (died: 1406), was the muwaqqit (timekeeper) in charge of regulating the daily rituals of the Islamic community) of the Umayyad Mosque. Later he traveled to Cairo, where tradition places him as a student of Ibn al-Majdî. Sibṭ al-Mâridînî wrote extensively on mathematics and mathematical astronomy. Like his grandfather, he was especially interested in astronomical instruments. The bio-bibliographical sources list some 25 treatises, many of which exist today in multiple copies. According to the historian al-Jabartī (died: 1822), Sibṭ al-Mâridînî's works on mîqât (ritual timekeeping) and astronomical instruments were still being studied in the curriculum of Cairo's al-Azhar, one of the preeminent educational institutions in the Islamic world, at about the beginning of the 19th century. (Biographical encyclopedia of astronomers, 2007).