Eğinli Nu‘mân Efendi’ninTebyînü A‘mâli’l-Misâha’sı
Authors: Eğinli Nu‘mân Efendi 
Published: October 2024

One of the significant ways to determine a nation’s future role and place in history, based on the experiences gained, is to understand the processes through which the nation acquires scientific knowledge. In recent years, studies on Ottoman sci- ence history in our country have been evaluated in this con- text, yielding valuable results. This study focuses on the work of Eğinli Nu‘mân Efendi, an 18th-century Ottoman scholar, entitled “Tebyînü A‘mâli’l-Misâha.” This work constitutes the first Turkish land measurement book of European origin. In this regard, the book is of considerable historical significance. Nu‘mân Efendi, the author of the work, is a unique Ottoman scholar trained in the Ottoman madrasas. He was known by the nickname “Ebu Sehl,” meaning the father of ease. In many parts of the work, he complains about not receiving the value he deserved. Ironically, this value is being realized almost three centuries after his death through an examination of the works he left behind. His other works, such as “Ted- bîrât-ı Pesendîde,” “Duhan Risâlesi,” and “Destan,” have been translated into modern Turkish in previous studies. “Te- byînü A‘mâli’l-Misâha” is his only known work on mathemat- ics, and this study has been the subject of extensive research. In dictionaries, “mesâha” generally corresponds to “land measurement,” which, in our scientific literature, translates to applied geometry. In this context, the books on mesâha that constitute the Ottoman mathematical literature begin with basic geometric definitions and classifications, followed by perimeter, area, and volume calculations. The tradition men- tioned has changed in “Tebyînü A‘mâli’l-Misâha.” This work begins with the content of a classic mesâha book but continues differently by introducing a tool called the planchette-table, describing its use. The most interesting aspect of this work, in our opinion, is the mathematical proof of the accuracy of the measurements obtained using the table. In this study, Nu‘mân Efendi first explains each measurement model he proposes and then proves the accuracy of his proposed method by pro- viding examples within the scientific culture of the time. The examples presented in this paper involve solving triangle simi- larity problems by applying the following theorems, which we refer to as “theorems of similarity.” This concern regarding the mathematical proofs observed by Ottoman scholars pro- vides a perspective that researchers should not overlook when studying Ottoman science history. Another interesting aspect of this study is the systematic arrangement of the presented information. Each new piece of information provided in this paper is built on the previous information, ensuring that read- ers can easily understand and trust the content. The book, described by Nu‘mân Efendi as “written so that everyone can easily read and understand it,” reflects this purpose. This study examined Eğinli Nu‘mân Efendi’s work “Tebyînü A‘mâli’l-Misâha” in light of the above-mentioned aspects, and the work has been rewritten in Latin letters and present- ed to contemporary readers. While this study aims to inform its readers about the topic, it is also hoped to serve as a new source for future research on Ottoman mathematics and the history of mesâha.