Triangle from the Past: A Late Ottoman measuring instrument

Abstract

In this study, we present an unusual instrument that is rarely seen in museum collections. This richly decorated brass triangle belongs to a group of objects used by Ottoman architects and engineers. The level or havāyī terāzū is an instrument that has a wide application in geometry, architecture, military engineering, hydraulic works, and topography. With its rich decoration, it can certainly be seen as a work of applied art and an artifact that – alongside its functional role – also has a symbolic value. Dating of the level is possible based on comparisons with other finds, especially those from the collections of the Pera Museum in Istanbul and the Petrovic Collection at the Canada Science and Technology Museum in Ottawa. However, the level from the Museum in Doboj is significant because it was cast in a form that is unique among levels known to date. Detailed descriptions of the instrument can be found in medieval Persian and Arabic treatises, later Ottoman studies, and Renaissance European publications. Finally, this study provides an opportunity for the wider public to learn about a lesser-known artifact, and to encourage the publication of similarly little-known ones.