This is a model of a device used for measuring blood lost during phlebotomy (bloodletting) sesions, a popular therapy in the Arab world. It is illustrated in Al-Jazari's manuscript, the 'Kitab fi ma'rifat al-hiyal al-handasiyya' ('Book of Knowledge and Ingenious Mechanical Devices'), which was written in 1354 in Egypt during the Mamluk dynasty (1250-1517). This book described the construction, components, and functions of 50 mechanical devices, or automata. Two scribes are seated above the device and their actions describe the amount of blood to be let.
© Science Museum / Science & Society Picture Library