A Survey on two Ottoman Quadrants of the Eighteenth and Nineteenth Centuries and a Treatise on Altitude Preserved in the Erzurum Museum, Türkiye Erzurum Müzesindeki On Sekizinci ve On Dokuzuncu Yüzyıla Ait İki Osmanlı Çeyrek Daire ve Bir İrtifa Risalesi Üzerine İncelemeler

DANIŞAN G., Günergun F.

Osmanli Bilimi Arastirmalari, vol.27, no.1, pp.78-104, 2026 (Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 27 Issue: 1
  • Publication Date: 2026
  • Doi Number: 10.26650/oba.1688299
  • Journal Name: Osmanli Bilimi Arastirmalari
  • Journal Indexes: Scopus, Central & Eastern European Academic Source (CEEAS), Index Islamicus, Directory of Open Access Journals
  • Page Numbers: pp.78-104
  • Keywords: 18th-19th Century, Altitude Treatise, Ottoman Astronomy, Portable Astronomical Instruments, Wooden Quadrant
  • Istanbul University Affiliated: Yes

Abstract

This study examines two Ottoman wooden quadrants, each dating from the 18th and 19th century (Inv. Nr. 494 and 2008/26 (E)) kept in the Yakutiye Madrasa Manuscript Collection of the Erzurum Museum (Türkiye), as well as the printed edition of the altitude treatise (Inv. Nr. 2008/26 (E)) titled Tercüme-i Gedûsî, translated from Arabic to Turkish by Süleyman Murad b. Ömer b. Ahmed Sa'di el-Gedûsî. This translation, revised in 1894 by Hazergradî Hasan Şevkî Efendi, a teacher at Fatih Mosque (Istanbul), was later edited by the last Ottoman chief astronomer Hüseyin Hilmi Efendi (d.1924), and printed at the Mahmut Bey Printing House in Istanbul in 1329 H. (1911 AD). These materials reveal the multifaceted relationship between instruments and written sources in the production and transmission of astronomical knowledge during the late Ottoman period. Evaluating the instruments alongside the theoretical and practical information contained in the texts demonstrates that the astronomy of the period relied on both conceptual foundations and hands-on practice. This approach offers a novel perspective on the interplay between instrumental heritage and textual transmission in the Ottoman history of science. In this regard, the present study aims not only to examine the technical features and functions of the instruments but also to highlight their roles in the production, transmission, and use of scientific knowledge.