Science - Bloodletting device

Folio from a manuscript of Kitab fi Ma'Rifat al-hiyal al-hindasiyya by Al-Jazari (The Book of Knowledge of Ingenious Mechanical Devices, also known as Automata) 
Ink, gouache and gold on paper
Size: 39.3 x 27.2 cm 
Origin and time: Egypt, Safar 755 H/February-March 1354
Catalogue: Schätze des Aga Khan Museum
Inv. No. AKM 00011

In 1206, Badi az-Zaman ibn ar-Razzaz al-Jazari wrote a treatise on mechanical devices called Kitab fi ma'rifat al-hiyal al-hindasiyya (The Book of Knowledge of Ingenious Mechanical Devices) for the Artuqid Sultan Nasir ad-Din Muhammad who was fascinated with machines. This book included descriptions and illustrations of the devices invented by al-Jazari and was repeatedly copied and distributed across the Middle East. 

In the third section of his treatise, al-Jazari describes several devices for measuring the blood lost during phlebotomy (bloodletting). One of these devices consists of a brass mechanism – depicted in gold in the illustration. A bowl is placed on a platform and has a closable opening inserted centrally at its lowest point. The drainage pipe on the left side at the bottom directs the fluid in a cylinder, where a floating object was inserted. This is in turn connected via a thread to a counterweight outside the cylinder. The incoming fluid causes the floating object to rise, whereby the counterweight sinks, thus indicating how much blood was drawn off. The upper part of the device is occupied by two scribes. The scribe on the left holds a brass rod connected to the floating object which pushes the rod upwards when the amount of blood increases. The other scribe sits on a large red spool and rotates around his own axis when the fluid accumulates in the cylinder. At the same time, he also uses the rod in his hand to indicate the amount of leaked fluid. 
The figure illustrated on a larger scale is the “Measurer”. He is depicted sitting in the middle of a semicircular crenellated alcove. As soon as the bowl is filled with 10 Dirhams of blood (approximately an ounce or 30 grams), the “Measurer” pulls out his right arm and sets it on the ledge. This happens every time, as soon as the next 10 Dirhams of blood flow into the basin and each time the “Measurer” raises one more finger. VD

This folio comes from an Egyptian copy dated February-March 1354 AD, made for the Mameluke amir Nasir al-Din Muhammad ibn Tulak al-Hasani al-Malik al-Salih at the time of Sultan Hasan’s second reign (1354-1361). The Arabic description at the top of the page reads: “And I am showing an illustration in the shape of a wash basin, the stand, and the cylinders.” While most of the extant folios from this codex, including its colophon, are in the Süleymaniye Library in Istanbul (Aya Sofya 3606), a number of the original illustrated pages remain dispersed.LA