The holders of astronomical knowledge, in late nineteenth century Turkey, were rather diverse. While Ottoman officers taught astronomy (ilm-i heyet) at the Military School (Mekteb-i Harbiye) based on translations made from European astronomy textbooks, the timekeepers (muvakkits) and the astrologers (müneccims) prepared calendars for every day use. The Rasathane-i Amire (lit. Imperial Observatory) founded to exchange meteorological data between European and Ottoman stations, where Salih Zeki (1864-1921) acted as director for almost 15 years was, also an institution in which astronomical observations may have been carried out occasionally. Salih Zeki’s interest in astronomy seems to have originated in late 1880s when he was appointed as assistant-director to the Technical Office of the Ottoman Administration of Posts and Telegraphs after his return from Paris where he had studied in the Ecole Supérieure de Télégraphie. Émile Lacoine (1835-1899), the technical councellor of the Ottoman Administration of Posts and Telegraphs and the vice-director of the Imperial Meteorological Observatoy seem to have initiated Salih Zeki to astronomy and calendar computing. Salih Zeki’s published first a calendar for the financial year (Rumi) 1308 [1892]. Then, he co-authored E.Lacoine’s Takim-i Cedid (New Calendar) computed for the Rumi year 1310 [1894]. He became the director to the Imperial Meteorological Observatory in 1896 following the death of its founder A. Coumbary (1826-1896), a position he held until 1909. Beside his administrative work in the Observatory, he compiled his two major works on the history of mathematics and astronomy, taught mathematics, physics and astronomy in Istanbul Darülfünun (University). His request to explore the effects of the 1899 earthquake in Aydın was approved by the Government, but no records of this mission are presently available.Salih Zeki participated to the Conférence Internationale de l’Heure (Paris 1913) where the Ottoman Government signed the agreement for the Establishment of the Bureau International de l’Heure and started the preparatory work for the adoption of Universal Time. Salih Zeki was commissioned by the Ministry of Education to participate to the expeditions led by European astronomers to observe the total solar eclipse in Trebizond on August 21, 1914. The actual absence of documents regarding the expeditions leads us to argue that neither Salih Zeki nor other foreign astronomers observed the total eclipse in Trebizond.Salih Zeki, besides publishing popular articles on astronomy, translated from French two textbooks: Yeni Kozmografya (New Cosmography, Istanbul 1915) and Muhtasar Kosmografya (Abridged Cosmography, Istanbul 1916). A note in Yeni Kozmografya indicates that he proposed to the Ottoman Government a project to improve the Islamic lunar calendar (Mali/Rumi takvim). He also edited the Avalim-i Felekiye (Cosmography, Istanbul 1909), a textbook compiled by H. Hagopyan based on various sources, E. Loomis (1811- 1889) being one of them. According to Halil Ethem Eldem (1861-1938) the museologist, Salih Zeki’s last work was the catalogue of astrolabes conserved at the Imperial Museum in Istanbul.

The holders of astronomical knowledge, in late nineteenth century Turkey, were rather diverse. While Ottoman officers taught astronomy (ilm-i heyet) at the Military School (Mekteb-i Harbiye) based on translations made from European astronomy textbooks, the timekeepers (muvakkits) and the astrologers (müneccims) prepared calendars for every day use. The Rasathane-i Amire (lit. Imperial Observatory) founded to exchange meteorological data between European and Ottoman stations, where Salih Zeki (1864-1921) acted as director for almost 15 years was, also an institution in which astronomical observations may have been carried out occasionally. Salih Zeki’s interest in astronomy seems to have originated in late 1880s when he was appointed as assistant-director to the Technical Office of the Ottoman Administration of Posts and Telegraphs after his return from Paris where he had studied in the Ecole Supérieure de Télégraphie. Émile Lacoine (1835-1899), the technical councellor of the Ottoman Administration of Posts and Telegraphs and the vice-director of the Imperial Meteorological Observatoy seem to have initiated Salih Zeki to astronomy and calendar computing. Salih Zeki’s published first a calendar for the financial year (Rumi) 1308 [1892]. Then, he co-authored E.Lacoine’s Takim-i Cedid (New Calendar) computed for the Rumi year 1310 [1894]. He became the director to the Imperial Meteorological Observatory in 1896 following the death of its founder A. Coumbary (1826-1896), a position he held until 1909. Beside his administrative work in the Observatory, he compiled his two major works on the history of mathematics and astronomy, taught mathematics, physics and astronomy in Istanbul Darülfünun (University). His request to explore the effects of the 1899 earthquake in Aydın was approved by the Government, but no records of this mission are presently available.Salih Zeki participated to the Conférence Internationale de l’Heure (Paris 1913) where the Ottoman Government signed the agreement for the Establishment of the Bureau International de l’Heure and started the preparatory work for the adoption of Universal Time. Salih Zeki was commissioned by the Ministry of Education to participate to the expeditions led by European astronomers to observe the total solar eclipse in Trebizond on August 21, 1914. The actual absence of documents regarding the expeditions leads us to argue that neither Salih Zeki nor other foreign astronomers observed the total eclipse in Trebizond.Salih Zeki, besides publishing popular articles on astronomy, translated from French two textbooks: Yeni Kozmografya (New Cosmography, Istanbul 1915) and Muhtasar Kosmografya (Abridged Cosmography, Istanbul 1916). A note in Yeni Kozmografya indicates that he proposed to the Ottoman Government a project to improve the Islamic lunar calendar (Mali/Rumi takvim). He also edited the Avalim-i Felekiye (Cosmography, Istanbul 1909), a textbook compiled by H. Hagopyan based on various sources, E. Loomis (1811- 1889) being one of them. According to Halil Ethem Eldem (1861-1938) the museologist, Salih Zeki’s last work was the catalogue of astrolabes conserved at the Imperial Museum in Istanbul.