Salih Zeki’s First Lecture in Darü‘l-fün？n Konferanslar？: Locating its Main Source

Salih Zeki presented a series of lectures on mathematics, which were later published in the old Turkish script. They are about certain developments and fields that arose in mathematics in the 19th century. He talks in a concise and historical manner about non-Euclidean geometries and their discovery in the first five lectures of the first volume. In the first lecture, he presents the gist of his views concerning how these geometries were discovered. Salih Zeki’s lecture seems to be the first addressing and dealing with this discovery among the available printed materials in Turkish. It, thus, certainly deserves to be examined. My aim is to determine his main source on which he structured his account of this discovery in order to appreciate, and asses better his mathematical, philosophical and methodological concerns