The Mongol Who Built a Mural Sextant
بِسۡمِ ٱللهِ ٱلرَّحۡمَـٰنِ ٱلرَّحِيمِ Shaykh Abu Mahmud Hamid ibn al-Khidhr al-Khujandi ( r.a. ) was a mathematician and astronomer from Khurasan, a kingdom covering what is now Afghanistan, Turkmenistan, and Uzbekistan. He was of Mongol origin and lived in the late 10 th century. He was born in Khujand. There is a bronze bust of him in a park in modern Khujand, now part of the Republic of Tajikistan. What little we know from his life come from his surviving writings as well as from comments made by Imam Naswr ad-Din Muhammad ibn Muhammad ath-Thusi ( q.s. ). We are fairly certain that Shaykh al-Khujandi ( r.a. ) was one of the rulers of the Mongol tribe in the Khudzhand region. However, we do know that he was responsible for building one of the largest astronomical instruments of the era, the mural sextant near Rayy, in modern Iran. The mural was done on a 60-degree arc between two interior walls of a building. It measures about 43...