Gelenbevi Ismail Efendi


Ismail Gelenbevi was an Ottoman Turkish mathematician and Professor of Geometry at the Naval College in Istanbul, Turkey.
His life and work are well documented in several scholarly works in English and Turkish
such as the thesis by Alaettin Avci "Turkiyede Askeri Okullar Tarihcesi", 1963, published by the Research and Development Office of the Turkish General Staff,
and M.K. Karabela's PhD thesis on "The development of dialectic
and argumentation theory in
post-classical Islamic
intellectual history",
Born in 1730 in the town of Gelenbe near Manisa, at that time in the Province of Aydin in Western Anatolia, he is known under the name "Gelenbevi", which means "de Gelenbe" in French, and "von Gelenbe" in German. He studied in İstanbul where he rose through the Ottoman examination system to the rank of "Müderris" or professor, at the age of 33.
At the request of the Sadrazam or Grand Vizier Halil Hamit Pasha , and of the Fleet Admiral Cezayirli Hasan Pasha, he was appointed to a professorship in mathematics at the new Naval College in Kasımpaşa, on the Golden Horn, in Istanbul where he worked with other Ottoman reformers such as the Franco-Hungarian military engineer and aristocrat François Baron de Tott. Gelenbevi received an award from the Emperor Sultan Selim III for his very accurate ballistic computations.
Gelenbevi Ismail published some thirty five scientific articles including a treatise on the game of chess, written in Turkish and Arabic. He is credited with the introduction of logarithms in Turkey. The late Orttoman era Cabinet Minister Mehmet Cemaleddin Efendi , senior judge of the Ottoman Empire and Şeyhülislam or Cabinet Minister in charge of religious and legal matters, the Turkish cinema pioneer and photographer Baha Gelenbevi, and Professor Erol Gelenbe at Imperial College, London, are direct descendants of Gelenbevi Ismail. A selective public high school in the Fatih district of Istanbul
bears his name.