[ASTRONOMY - MATHEMATICS - ARABIC MANUSCRIPT: JAYB & MUQANTARÂT; [i.e. 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. [ca. 1820-1840], [Istanbul].
Original manuscript without binding. 12mo. (16 x 11 cm). In Arabic.  p., drawing, and tables. 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. 'Istinsah' [i.e. copied] by unspecified author in the early 19th century according to the special paper with 'ahar'. Sibt al-Maridini , full name Muhammad ibn Muhammad ibn Ahmad ibn Muhammad ibn al-Ghazal (1423 – 1506 AD), 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". 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 Almuqantar, and 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", including some 'sinus mathematics' with two impressive tables on the opposite page.