SALAH AL-DIN MUSA B. MUHAMMAD B. MAHMUD QADI-ZADA AL-RUMI (D.1140 CA), SHARH ASHKAL AL-TASIS, A COMMENTARY ON THE ELEMENTS OF GEOMETRY, NEAR EAST, MAMLUK, 15TH CENTURY

F.1a lists some titles which were originally included in the same volume but which are now lost. The book now contains only Sharh Ashkal al-Tasis, a commentary of Shams al-Din Samarqandi’s Ashkal al-Tasis. The author is very likely to be Salah al-Din Musa ibn Muhammad b. Mahmud Qadi-Zada al-Rumi, as another title by the same author is listed in the index. Brockelmann lists the same title also under a different author Muhammad ‘Ali b. Mubarakshah Shamseddin Mirak al-Bukhari (d.1340) (S II, 297).

Qadi-zada al-Rumi was born in Turkey from a family of judges (the word qadi means judge). He moved from Bursa to Samarqand under Timur and worked at the court of Ulugh Beg. He was one of the heads of the Samarqand observatory and resided in Samarqand until his death, after which he was buried close to the mausoleum of Shah-i-Zinda.

This commentary of elements of geometry is based on Shams al-Din Samarqandi’s Ashkal al-Tasis, and comments on Euclid and Ibn al-Haytham. The treatise focuses on preposition V of Book I of Euclid’s Elements, also known as the pons asinorum or ‘bridg of asses’ namely, that the base angles of an isosceles triangle are equal (illustrated on f.11b and f.12a) and Ibn al-Haytham’s interpretation (f.15b).

A later note at the end of the manuscript states that it was finished in the month Rabi’ in the year 827 AH which corresponds to the beginning of 1424 AD.