The concepts of rhythm and measurement lie at the foundation of Cevdet Erek’s works and site-specific installations, which investigate the units, structures, and forms that guide our perception of space and time. In 2007, Erek produced his first ruler, which begins with the year of his birth. Since then, he has continued to make rulers to mark and interpret successive events and relationships drawn from a wide spectrum that ranges from the temporal units of day, night, week, and year, to individual and social turning points, and to historical ruptures like coups and wars.“Ruler dOCUMENTA (13)”, on the other hand, is a series of ruler prototypes Erek produced from a tree chopped down just before the exhibition opened in the city of Kassel in Germany. The rulers have not been given their final shape, and because they are displayed alongside the log from which they were obtained, they signify the potential to be duplicated in the future. Using the Second World War, during which Kassel was torn down, as a starting point, the artist wrote “1945” in pencil on the growth ring visible on the first segment of the tree. Subsequent years, marked usually at five-year intervals, depict when editions of documenta – a symbol of post-war Germany