The Ritual Ablution (Wuḍū- الوضوء‎) and the Basin of the Slave


This is a basin that allows the ritual ablution (Wuḍū) with the help of an automaton of a young slave who holds a jar of water, a towel, and a comb in his other hand. We have already encountered a peacock that discharges water from its beak, and there are three different tools for Wuḍū that we will meet later. As far as I know, there are no other examples of automatons or “patents” for the ritual Aablution before al-Jazari. I was happy to find out that in 2009 at the Electric Engineers Convention (IEEE) held in Kuala Lumpur, an article was presented on an ” Automatic Ablution Machine using Vision Sensor”  in the hope of saving water. The multitude of tools at al-Jazari can attest to the importance of the ceremony in the Artuqid court in Diyarbakir or that the Ritual Ablution is especially suitable for the desire of al-Jazari for Automaton and allowed him to make use of his favorite siphons and buoys. Either way, it has made me read a little bit more about the wudu, and this will be the center of this post.

The Basin of the Slave, Topkapi Manuscript, 1206

The Ritual Ablution (Wuḍū- الوضوء‎)

Wuḍūʾ in Islam is a ritual purification or ablution done before the prayer. According to tradition, when the prayer, one of the five pillars of Islam, was given to Muhammad, the angel Gabriel came to him, hit the earth with his heel, and the water gushed out. The Angel Gabriel purified himself, and thus Muhammad learned how to do the Wudu. Then he returned home and taught Khadijah, his first wife as well.

The source of the Ritual Ablution is in the words of the Qur’an:

” O you who have believed, when you rise to [perform] prayer, wash your faces and your forearms to the elbows and wipe over your heads and wash your feet to the ankles. And if you are in a state of janabah, then purify yourselves. But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and hands with it. Allah does not intend to make difficulty for you, but He intends to purify you and complete His favor upon you that you may be grateful.

Surah 5 -The Table Spread(سورة المائد) verse 6

Muslims believe that physical purity is the basis of spiritual purity and a necessary condition for prayer (الصلاة). This chapter of the Qur’an, or any other, does not detail the ablution process or discuss the full-body ritual purification called Ghusl (غسل). The details of purification appear in the hadith (الحديث), A collection of laws, stories about Muhammad, his way of life, and his statements and advice on various topics. The hadith is second only to the Qur’an.

How does it work?

A young copper slave kneels on a square platform, holding a jug of water in his right hand and a towel and comb in his left hand. At the four corners of the stage are columns bearing a handsome castle with a dome topped by a bird. Adjacent to the stage is a half-basin with a good-looking duck crouching on the floor. From an engineering point of view, all the components, float, and siphons are familiar to me and my readers from al-Jazari’s previous works, respectively, I have given up on the traditional coloring of the text in blue. I’m fascinated by his ability to connect them each time in a way that really tells a story, and in this case, the story is the appearance and disappearance of the ablution waters. This is the diagram of the mechanism with captions that I added:

The servant brings the device when the tank is filled with the amount of water necessary for the purification ceremony and pulls the plug. Water goes down the pipe hidden in the castle column and through the young slave’s arm reaches the top of the jug. This whole path is concealed to enhance the wonder of the automata and its operation. The spout is a siphon that reaches the bottom of the water jug. I’ve written about siphons here. The water will not come out until the water level exceeds the arc of the siphon. The air in the jar has no outlet; apart from the thin tube attached to the whistle, the king would imagine the bird on top singing for him and announcing that the ceremony is beginning. Soon after, the water in the jug will reach a sufficient height, and the water will come out of the spout and allow the king to perform the purification. The water will be collected in the adjacent sink, but the latter lacks a drain, so the water will accumulate. The handsome duck at the bottom of the sink is also a siphon, and when the water reaches a height indicating that the ceremony has ended, the duck will empty the sink into the lower water tank. In this container, a float is attached by a chain to the slave’s left arm, located on a hinge. When the float rises, it will release the arm, which will move, offering the king the towel and comb.


Reflections on the Basin

While wandering, I tried to imagine the Artuqid ruler Nasir al-Din Mahmud making the Wudu with al-Jazari’s automata. The Wudu includes several components, and there are differences between Sunnis and Shiites. We begin by connecting the bathing to the ablution ritual by reciting (possibly only in the heart) the Basmala (Arabic: بَسْمَلَة, = بِسْمِ ٱللَّٰهِ ) literally “In the name of Allah but  a short of the Islamic phrase “In the name of God, the Most Gracious, the Most Merciful.”This is followed by a ritual washing that includes a triple wash of the face, including washing the mouth and nose, triple washing of the hands, including elbows, symbolic cleaning of the head with water (مسح), and bathing both legs up to the ankles. We conclude by saying the Shahada ( ٱلشَّهَادَةُ), which is the Islamic oath:There is no god but Allah, and Muhammad is His messenger.”

Wudu bathing at the entrance to the mosque in Dashahi. Photo by Pale blue dot

The ablution is thus a part of the prayer and “justifies” Al-Jazari’s multiple devices. On the other hand, there is something playful and amusing about the basin of the slave that contradicts (in my mind) the seriousness of the ceremony. But maybe it’s just me, and in the 12th century, prayer sat perfectly with the wonder of the water appearing and disappearing like a magic wand.



Two additional basins for bloodletting and what can we know about al-Jazari’s education?


Al-Jazari described four basins for measuring the amount of blood during bloodletting. I already covered two of them: The basin of the monk was explained here with some background on the history of bloodletting, and I explained The Basin of the Two Scribes here with a discussion on the uniqueness of al-Jazari in comparison to other tools for bloodletting. The remaining two: The Basin of the  Reckoner (الحسيب -alhasib) and the Basin of the Castle are almost identical in their mechanism to those explained. The main difference is how the cumulative amount of blood is displayed. This made my mind wander further, and this time what can we know about al-Jazari ‘s education?

The Basin of the Reckoner, dispersed manuscript, 1315, the Museum of Fine Art, Boston.

What do we know about al-Jazari’s education?

We don’t know anything about al-Jazari’s education apart from what he himself wrote in the introduction:

“I have studied the books of the earlier [scholars] and the works of the later [craftsmen] –masters of ingenious devices with movements like pneumatic [movements], and water machines for the constant and solar hours, and the transfer by bodies of bodies from their natural positions. I have contemplated in isolation and in company the implications of proofs. I considered the treatment of this craft for a period of time and I progressed, by practicing it, from the stage of book learning to that of witnessing, and I have taken the view on this matter of some of the ancients and those more recent [scholars]. I was fervently attached to the pursuit of this subtle science and persisted in the endeavor to arrive at the truth. The eyes of opinion looked to me distinguish myself in this beloved science. Types of [machines] of great importance came to my notice, offering possibilities for types of marvelous control”

Beyond these lines, we have no information about his education or teachers. However, he was an avid reader who read quite a bit. I wrote about the library of al-Jazari here. His mathematical knowledge, at least according to the book, is limited. I wrote about it here. He is a diverse craftsman in a way that is almost impossible today; he was designing in metal, wood, and paper pulp. He worked with a large number of metals: iron, bronze, copper, brass, silver, and gold. He worked in a wide range of techniques: soldering, casting and hammering and produced himself pipes and gears. In fact, other than the raw materials, he does everything himself. The Makers movement, which is an umbrella term for independent inventors, designers, and tinkerers who preferred to be makers instead of consumers, could use al-Jazari as a role model.

What do we know about medieval education?

From the 8th century AD, elementary schools became generally adopted between the ages of six and ten. The classes were sometimes held in a shop or private houses, but more often in a mosque or building connected to it. The base for learning was the Quran. The pupil copied a passage of the  Quran on his board, and only after he had memorized it, moved to the next passage. We should remember that Muslims believe that the Quran was orally revealed by God to the final Prophet, Muhammad, and not only the Quran is the basis of the religion of Islam, but also a guideline for worship, the book of laws and an instruction book for the proper behavior. It was relatively common to see a procession in honor a ten years old child as a reward for studying the entire Quran by heart.

In addition to the Quran, the students learned the Five Pillars of Islam, including the ritual washing and the prayer. The non-religious teaching elements included verses of poetry as a model for writing and something about numbers and calculations. The schools were intended for all, and initially, no payment was collected for religious reasons. Over the years, it has changed, and the schools have received gifts, food, and money. At the end of the Umayyad Caliphate ((اَلْخِلافَةُ ٱلأُمَوِيَّة‎ in the 9th century, there is evidence of a school that contained 3000 pupils, it is clear that such an organization cannot operate without resources. Al-Jazari likely studied at this kind of school.

When the student completed the four compulsory years, he could go on for another three more years in which he studied grammar, rhetoric, and literature as well as the history of Islam. There are no references to literature or history in Al-Jazari’s book, and it is difficult to know if he continued his studies beyond the first four years. I didn’t find a medieval painting, but the contemporary photograph of Muslim pupils who are memorizing the Quran is probably quite similar to the 12th century:

Muslim students study the Quran in the mosque in India

After the four years of compulsory education, most of the students worked with their parents in the fields or were sent to work with a master craftsman as an apprentice. The work as an apprentice was conducted in small workshops of the bazaars(بازار). The bazaar is a network of narrow streets,  wide enough for a loaded donkey to pass through, usually covered with a wooden roof or some shaded areas, in which the workshops simultaneously created and sold their merchandise. The workshops were organized by guilds. Bernard Lewis, the historian who specialized in oriental studies, wrote the most authoritative work on Muslim guilds. He claimed that “guilds are one of the most interesting and characteristic phenomena of medieval Muslim civilization.” They are not merely equivalent of the European guilds, but so important was the guild in Muslim life, that in many cases the very topography of the Muslim city was determined by the needs of the guilds. From Morocco to Java, with surprising uniformity, the Muslim town rose around three or four central points, always the same. The first fixed point is the exchange. Around it is the toll-gatherer, the local mint (where there is one), the auction market, and the Muhtasib, or inspector of markets. The second center is the Qaisaria, a strong, closed-in building where foreign goods and valuables are stored. The third is the thread-market (Suq al Ghazl), where the women come to sell their own handiwork. And here, too, are the commodities women are likely to buy- butchers, bakers, etc. The fourth center is the university, usually attached to a mosque. Around these four centers are distributed the guildsmen; each guild in its own market.

At the head of the guild is the Sheikh. He is elected by the master craftsmen. Once selected, he was the unchallenged ruler of the guild, combining the functions of CEO, Treasurer, responsible for the taxes for the authorities responsible for the festivities and the concern for the sick and the poor. After him in hierarchy came elders among the master craftsmen, and next come the master craftsmen, the main body of the guild and finally the apprentices. The rank of a journeyman, skilled workers that have completed official apprenticeship qualification but may not yet work as self-employed master craftsmen so essential to European guilds, almost did not exist.

The apprentice (Mubtadi – مبتدئ) was taught by the master’s decision, for an unspecified period of time and without a specific curriculum. Some sources mention 1001 days that sound more like a ceremonial period than a three-year training. As the Apprentice training began at age 11, it was unlikely that they become independent craftsman at the age of 14. In most cases, the apprentice had to demonstrate his ability by producing a particularly complex piece of art (in Lewis’s words “masterpiece”), and then the master decided that the apprentice period was completed. The apprentice did not usually get paid during the apprenticeship, but the master did take care of their needs. Al-Jazari, unfortunately, does not write anything about this period of his life. I am pretty sure he went apprenticeship, and I would be very interested to know how was the experience.

It is impossible to talk about vocational education in Israel without entering a minefield. For many years, the youth of Edot HaMizrach (descendants of Jewish communities in the Middle East and North Africa ) were sent to vocational education( welding, metalworking, or barbershop training) regardless of their qualification. Only a highly detached consultant could send the deceased Ronit Matalon [an Israeli writer], with her amazing Hebrew to vocational education, and there are certainly many more examples.

However, the combination of vocational schools and apprentice training has many advantages. Germany, Switzerland, Denmark, as well as other countries have been demonstrating for years how vocational education can produce master craftsman that can not be replaced. I went to a traditional high school, and from there to the university and never, not even in Santa Clara or Portland, I didn’t feel that my education was short in comparison to the finest engineers in the world. Even so,  sometimes I want to go back and be the apprentice of al-Jazari and learn by doing and watching the very best.


The peacock which discharges water from its beak and peacocks as a symbol

אַז די פאַווע קוקט אויף אירע פֿעדערן – קוועלטזי, אָבער אַז זי קוקט אויף אירע דאַרע פֿיס- וויינט זי”

“When the peacock is looking at its feathers she (in Yiddish peacock is always feminine) is happy and when she looks at her scrawny legs she cries”)


The Peacock who discharges water from its beak to perform the ritual ablution is the sixth Peacock that we encounter in al-Jazari’s book; four peacocks in the water clock of the peacocks and another one in the basin of the peacock (in Hebrew). It’s time to talk about peacocks and many thanks to Dr. Shoey Raz that his comment sent me to this journey.

The peacock which discharges water from its beak. Topkapi manuscript, 1206.

How does it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in siphons can skip those bits. The hollow peacock is quite similar to in the Basin of the peacock, which was already explained. It is made from copper large enough to contain the water needed for the ablution washing. Its curved neck is a siphon. A siphon is a tube in an inverted “U” shape, which causes a liquid to flow upward, above the surface of a reservoir, with no pump, but powered by the pull of gravity. I wrote more on siphons here. The peacock is a water container, hollow as far as the beginning of its neck. The tail is divided halfway up by a plate, so that the upper half of the tail forms a separate chamber, while the lower half is connected to the main reservoir. Al-Jazari made a secret plug with an extension which reaches to the top of the peacock’s tail. A siphon would only work when the water in the peacock reservoir reaches the bend of the siphon. Water is poured into the belly of the peacock until it rises to a point beneath the curve.  To start the ritual ablutions, a servant puts it down on a handsome pedestal in front of the king, rotates the valve slightly, the valve opens, and the water from the upper chamber flows into the peacock’s belly, and water flows through the siphon into the peacock’s beak and the ablution ceremony begins.

The peacock as a symbol

The Peacock is a native Indian subcontinent and serves as the national bird, but he has a long history in the Middle East. The Greeks discovered the Peacock following the conquest of Alexander the Great. However, they still managed to insert it into the Greek myths:

In one of his attempts to hide his infidelities, Zeus turned his lover, a water nymph named Io to a beautiful white Heifer. Personally, I find it a little insulting although Hera connection to the cow symbol is ancient and has to do with being the goddess of motherhood and fertility. Hera, who suspected (rightfully so!) the Zeus is chasing other women again, begged Zeus to give her the heifer as a present, which, having no reason to refuse, he did. Hera then sent Argus, a giant who had 100 eyes, to watch Io and prevent Zeus from visiting her. Argus’s eyes turned him into the ideal guard – while some slept, others were awake and open. Zeus sent Hermes to distract and eventually slay Argus and Hera transferred all his eyes to the tail of a peacock to thank and honor her loyal servant. The importance of Peacock in legends and myths is understood. The green, deep blue colors, won him the admiration and awe. The “eyes” on the tail were seen as a sign of comprehensive vision and wisdom.

I heard of the Yazidis only because of the horrible genocide by ISIS, but they have an exciting and unusual religion. According to their creation story, God was originally “over the seas,” a notion reminiscent of the Biblical passage: “And the Spirit of God moved upon the face of the waters.” playing with a white pearl. The pearl was broken and became the substance from which the Earth and other planets were formed. Then God created Tawûsê Melek (in Kurdish: طاووس ملك) translated to English as Peacock Angel with six other angles known as ‘the Seven Mysteries.’ All seven are part of God and not separated from him, fragments of God’s light, like Rainbow colors, are the light refractions. Tawûsê Melek is associated with the blue color while at the same time is the source of all other colors/angels. When Tawûsê Melek came to earth, the Peacock was(is?) the physical embodiment of the Rainbow. You can read more on the Yazidi religion and the Peacock Angel here [in Hebrew].

In Islam, there is more than one perception of the peacock. Some claim that the beauty of the peacock tail is a proof of Allah capability to create beauty to satisfy men passion for grace, and they rely on the Quran, Surah 35:27:

“Do you not see that Allah sent down water from the sky with which We brought forth fruits of diverse hues? In the mountains, there are white and red, of diverse hues, and pitchy black; and human beings too, and beasts, and cattle? Diverse are their hues. From among His servants, it is only those who know that fear Allah.”

It’s amusing to know that Charles Darwin, the father of evolution, was confused by the beauty of the peacock tail and thought (in error) that this contradicts or at least not support his theory of evolution. In a letter to Asa Gray, an American botanist, he wrote:

“The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick.”

In the Hadith Bihar al-Anwar, a comprehensive collection of traditions compiled by Shia Muslim scholar Mohammad-Baqer Majlesi I found this beautiful tale:

“Glory be to Allah, the King, the Holy. Glory be to Allah, the Great, the Most High. There is no god except Allah, the Living and Self Subsisting. ” Whenever the Angel would say this tasbih [repetitive utterances of short sentences in the praise and glorification of Allah] all the peacocks that are on the Earth would start to praise Allah and open their wings up in respect (of Allah). Whenever this Angel in the heaven would become quiet, the peacocks on the Earth would become quiet. The Angel in the heaven had green hair and white wings, so white that no one has ever seen anything that white before.”

There is also this sermon from Imam Ali, the cousin, and son-in-law of Muhammad, the last prophet of Sunni Islam and the first rightful successor to Muhammad by Shia Muslims which is strangely similar to the Yiddish motto:

“The peacock walks with vanity and pride, and throws open its tail and wings and laughs admiring the handsomeness of its dress and the hues of its necklace of gems. But when it casts its glance at its legs, it cries loudly with a voice which indicates its call for help and displays its true grief, because its legs are thin like the legs of Indo-Persian cross-bred cocks.”

There’s additional material about the Peacock in Islam and other cultures, but I can’t conclude this section without writing that peacocks from India appear already in the Bible:

“For the king’s ships went to Tarshish with the servants of Huram: every three years once came the ships of Tarshish bringing gold, and silver, ivory, and apes, and peacocks.” (KJV Chronicles II, Chapter 9, verse 21)

In Hebrew, the text is “Tukii” which in Modern Hebrew means Parrot. However, most translators and commentators believe that the original meaning was peacocks mainly because, in Tamil, the language spoken in Southeast India, Peacock is named Tukii.

A mosaic from the old synagogue Maon, the 6th-century ad

Did al-Jazari know the Greek mythology story about Io and Hera?  I doubt that very much. Did he know the stories about the Peacock from the Muslim tradition? More likely, but we will never know. Maybe he just liked peacocks? We have only our imagination, and all answers are right.

The basin of the Peacock and the magic of automata


The basin of the peacock is an automatic basin for the ritual ablution- Wuḍū (وضوء). A servant brings the basin and positions it so that the beak of the peacock is facing the master. The servant pulls a hidden lever in the tail of the peacock, and water begins to flow. Then the left door opens, and mechanical slave emerges holding soap. Toward the end of the washing, the right door opens, and another mechanical slave emerges, this time, holding a towel, to dry the master’s hands. The automata are important to the history of technology. Methods invented to refine automata laid the basis for modern technology, but I hope in this post to talk about the source of the magic of automata.

Basin of the peacock, Topkapi manuscript, 1206

How Does it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in siphons or automaton mechanism can skip those bits.

The hollow Peacock is made of copper, large enough to contain the water needed for the purification ceremony. The arched neck is a siphon. A siphon is a tube in an inverted ‘U’ shape, which causes a liquid to flow upward, above the surface of a reservoir, with no pump, but powered by the pull of gravity. The siphon will work while the water in the peacock’s body would rise above the bend in the peacock neck. The peacock’s tail, which is spread out, is divided into two volumes. The bottom part is connected to the body of the peacock. The top is separated with a conical plug. This plug is connected by a curved lever which reaches the cover of the tail. At first, the servant fills the water when the plug is open, thus filling the body of the peacock and the lower half of the tail then he pushes the plug. At this stage, the water level is below the bend in the peacock’s, so nothing happens. With the plug in place, he fills the top half of the peacock’s tail and brings the basin to the king. Now the servant pulls the plug and connects all the Peacock parts. The water came down and rise over the bend of the Peacock neck, and the ritual ablution begins.

Al-Jazari and  Donald Hill settled for a side drawing, but my love M. insisted that it’s hard to understand the operation of the automaton without a frontal drawing. So I expanded the drawing:

When pouring water into the basin, the water flows through a hole in the floor into the lower chamber, and the float goes up until it pushes the mechanical slave holding the soap, causing him to move forward and open the left door and thus “offer” the soap to the king. The float doesn’t continue to rise because its movement is limited by the ceiling of the lower chamber. The water continues to rise to the upper chamber, so the second float begins to rise. His rod is shorter and triggers the second mechanical slave just before the water end. When the second slave moves forward, it opens the right door and offers a towel.


Automaton  (self-operating machine) magic

Automaton (plural automata) were not invented by al-Jazari. We know of automata in ancient Greece (Greek: αὐτόματον “acting of one’s own will”). The automata were used in temples and as accessories in the Greek theatre.  The first engineering text that I am aware of is by Hero of Alexandria, a mathematician, engineer, and scientist from the 1st century AD. “Automatopoietica” (αυτoματoπoιητικ ‘ ης) usually translated “on making automatons.” It is reasonable to assume that Hero knew of Aristotle’s “Poetics,” the earliest surviving work focusing on literary theory, in which Aristotle examine the principles behind epic poetry, comedy, and mainly tragedy. We can expand (?)  Poetics as the artistic elements which compose any art form and in our case, the art of automata. Today when we say poetic, we mean an emotional, leary style of expression. I don’t know if this was true in Alexandria, the book is a description of machines that perform “magic” with mechanics or pneumatics, such as automatic door opening in the shrine or statues that pours wine.

Al-Jazari developed and perfected the world of automata. He was the first to employ the camshaft as part of his automata, see the Castel Water Clock or the  Musical Boat [in Hebrew]. He also expanded the use of water flow, smart use of gears, buoys and balancing weights built a long list of automatons, some I already covered, and some I would translate from Hebrew in the near future.

The 18th century was the golden age of automatons. Most of them rely on the camshaft quite similar to the work by al-Jazari. It’s hard to choose between the many exotic examples. I can’t ignore the “Digesting Duck”  (Canard Digérateur) built by Jacques de Vaucanson. The Duck was the size of a living duck and was covered in perforated gold-plated copper to allow a view of the inside workings. It moved like a duck, wiggling its beak in the water, quacking, and most famously though, it could eat pellets offered to it, and then poop them. De Vaucanson claimed that duck contained a small “chemical laboratory” capable of breaking down the wheat grain. In the 19th century, it was found that Vaucanson had faked the mechanism, and the Duck’s poop consisted of pre-prepared breadcrumb pellets, dyed green.

An American artist’s (mistaken) drawing of the Digesting Duck.

I particularly like the automaton of Maillardet, also known (by error) as “Maelzel’s Juvenile Artist.” This is an automaton that can draw four different drawings and write in calligraphy three poems which, among other things, revealed the true creator, Maillardet, in contrast to its wrong reference to Maelzel. The full story appears in this video:

It is impossible to ignore that the eighteenth century is the age Romanticism (also known as the Romantic era), an artistic, literary, musical and intellectual movement originated in Europe. For example in a Hoffman story “The Nutcracker and the Mouse King” Mr. Drosselmeyer, who is a clockmaker and inventor, made a splendid gift for the children: a clockwork castle with mechanical people moving about. Also Olympia, in Der Sandmann (The Sand-man), the life-size mechanical doll with which Nathanael falls disastrously in love. Nili Mirsky in the epilog to “The Golden Pot and other stories “writes about chronic dualism: In the day a strict Prussian judge and in the night a romantic poet or the tension between the occult world and what is exposed in his stories. I suggest adding the tension between the mechanical doll and living humans.

The methods invented to refine mechanical dolls laid the basis for modern technologies, not only for robotics. For example, Edmund Cartwright patented the power loom in 1784, key development in the industrialization of weaving after a visit to “The Turk,” a mechanical doll who played chess and then proved to be a hoax. The mechanical part was real, but there was a concealed man who computed the chess moves. Cartwright wrote: “it is more difficult to construct a machine that shall weave than one which shall make all the variety of moves required in that complicated game?”. Thomas Edison incorporated the camshaft of al-Jazari or Maillardet with the music box and created the phonograph, the first device that allowed recording of music or voices. In general, there are many more examples of a drift of the technology from the “useless” world of automatons to the “practical” world, but I want to talk about the source of the magic.

The automaton is a mechanical doll who moves around and does things that are reserved only to living beings. I don’t think the automata maker confused themselves with the all-mighty creator. There is no mysticism or black magic in mechanical dolls, but there is small magic or amazement in the gap between the mechanical system and human behavior.  Allegedly this magic should disappear in the modern world. Drawing and writing poems are relatively simple tasks for a LEGO robot, which is only a toy. At MIT-Laboratory researcher investigate energy-efficiency in legged robots and created a mechanical “Cheetah” that goes far beyond any dream of makers in previous centuries. I am the last person who wants to reduce the wonder from the Cheetah but the kids watching the contemporary robot do not have the amazed face of the kids watching  “Maelzel’s Juvenile Artist.”  was the charm preserved? Why? I think magic is different. The observer in the thirteenth century and the eighteenth-century lived-in a world with a lot less technology and understood the world around him in a way that we lost. We live in a world saturated with technology and used to not understand most of it, even if we have a technological education. The cell phone in our hands is a powerful computer. Hundreds of engineers from various disciplines, electrical engineer, material engineers, chemists, and a solid-state physicist were needed to produce the microprocessor alone. I doubt that there is one person in Apple or Samsung that knows all the details of the microprocessor, and this is before we even discuss the touch screen or the antenna. We live (well!) with our lack of understanding and content with using it without knowing “the details.” In the 18th century, and before, the automaton was a demonstration of the strength of technology. It allowed René Descartes, the famous French philosopher, mathematician, and scientist to think (fantasize?) that one day the scientific principles at the base of Humans and animals would be revealed, just like we can understand the mechanism of the automaton. This was a challenge to religion and a song of praise to science and its powers. Not every innocent observer is Descartes, but this is the root of our amazement. When we live in a technological world we don’t understand, the astonishment question is very different. Why be astonished more (or less?) by a robot or a cell phone or a game of virtual reality? The magic of the old mechanical dolls is precisely the fact that we can see the technology does its wonders, you can see the gears fit, and the reader (pushrod) moves over the camshaft. We, the eighteenth-century observer and al-Jazari, are, for one moment, in the same place of admiration.

Two Scribes and Bloodletting


This is the second basin of al-Jazari for blood-letting, “from which the quantity of blood which it holds can be ascertained.” Its mechanism is almost identical to “The Basin of Monk,” explained here with some additional background on the history of bloodletting. The main difference is in the design; two scribes are sitting on a raised platform, one writer rotates, and his pen indicates the amount of blood collected in the same manner as the monk. The other scribe has a writing pad that rises so that his pen, which does not move, indicates the amount of blood. We have plenty of information, medical and images which documented bloodletting. There is no precursor bloodletting tool before al-Jazari and all bloodletting tools after his time are simply bowls with marking. And the question is why?

The basin of the two scribes. Detached folio from a Manuscript,1315

How Does it work?

The mechanism is almost identical to the basin of Monk. The differences are so tiny, if the readers are interested in them, he or she probably do not need my mediation. Still, for the comfort of my readers, I provide my adaptation of the modern drawing by Donnell Hill, the book translator and annotator. If there are any errors, the responsibility is all mine. The technical explanation, as always, will be colored in blue, so anyone who is not interested in pulleys or balancing weight can skip those bits.

Both scribes are sitting on an elevated platform on four columns. The scribe to the left sits on the main pulley and is holding a pen which is an indication of the amount of blood collected so far. Two ropes are connected to the main pulley through the hollow columns and two small pulleys. At one end there is a float, and the other end has a balancing weight. The ropes are tight before the beginning of the bloodletting, and the pen is indicating zero. The blood goes to the basin and the drain and is collected in the container where the float is located. As a result, the float goes up and release rope through the pulley, the weight continues to pull down, and the main pulley with the scribe on it would rotate. The float is also connected to a rod with a writing pad at the end. As the amount of blood accumulates, the writing pad will rise as well. The fixed pen in the hand of the second scribe would also indicate the amount of the blood.


Bloodletting tools throughout history

I don’t know if there are any other medical procedure as bloodletting that got so many medical or artistic expression. This is just a small sample:

Pictures from right to left:

  • A drawing of bloodletting on a Greek vase from the fifth century BC
  • A Bowl with a scene of bloodletting from Iran, the first half of the 13th century, Islamic Art Museum, Berlin.
  • Caricature of bloodletting by James Gillray, 1804.

Pictures from right to left:

  •  A Physician is letting blood, 13 century, Aldobrandino of Siena. British Library, London.
  •  A surgeon binding up a woman’s arm after bloodletting. Oil painting by Jacob Toorenvliet, 1666.
  • Photo of bloodletting from 1860, one of three known photographs of the procedure.

In all these photos and many others, the blood is collected in a bowl.  In 1979 the Smithsonian Museum published an impressive catalog of bloodletting tools. The catalog is available online and is full of great information including an article summarizing the topic and plenty of images of bloodletting instruments; there is nothing more than a bowl with graduated marking:

Bleeding bowl with graduated markings to measure the amount of blood. Made by John Foster of London after 1740.

How do we explain al-Jazari choice?

Quite a bit of al-Jazari work relies on his predecessors. Al-Jazari himself was the first one to reference previous scholars as I showed in the Castle Clock or in The Fountain of the Two Tipping Buckets (in Hebrew). Sometimes the technological leap forward is very large, for example, water wheel pump and sometimes less significant as in all the fountains. But not only that there is no precedent to al-Jazari’s designed for measuring blood there is no ” sequel”; no one used al-Jazari ideas. It is worth mentioning his book was quite popular; there are not many manuscripts from the 12th century with 15 remaining copies and bloodletting continued for about 700 more years.

Surprising?  Maybe not. Al-Jazari solution is complicated and requires a lot of work. There is no comparison between the serial production of a ceramic bowl even in the 12th century, and fine mechanics. The materials are more expansive, the basin is made out of brass, and the scribes are made of copper. All this raised the final cost. Also, al-Jazari’s solution is much more difficult to clean and maintain, and offers only one clear advantage: it is more fun and allows the patient to track the amount of blood easily.

I have no evidence in the text, but I am convinced that al-Jazari understood the cost of material, the amount of work and the complexity of maintenance as well as I do. So why did he chose as he did? I have two proposals, and you are welcome to offer your own.

  1. I discussed this question with my young son. He said that if I were asking him in sixth grade to invent a tool that measures the amount of blood during bloodletting, he would look for a solution like this (he added a lot of limitations due to what he knew at that time) because it’s much more “cool.” Al-Jazari was an engineer serving in the Palace in Diyarbakir. The cost was no consideration for his employers, and there was no shortage of servants and slaves. However, his love for automatons constantly sought surprising solutions to the problems around him. This combination of an engineer “crazy” for automatons without constraints won’t be back.
  2. My love M. turned my attention to the Linguist Roman Jakobson and his much-cited article “Linguistics and Poetics” which maps the language to its essential function. For example, The referential function corresponds to the factor of Context, and its role is to transmit information. Some say that this is the main function. I want to focus on the poetic function; it focuses on the message himself, rather than the addresser (sender) or addressee. I took the liberty to take a post of her (in Hebrew) “One Great Illustration and Ora Eitan” and modify it slightly:

“According to the linguist Roman Jakobson” The primary intent of the message as such [in our case, the message is the automaton itself, the way it fulfills its purpose. AG] is the poetic function of language. In Jakobson words: The set (Einstellung) toward the message as such, focus on the message for its own sake, is the POETIC function of language.”

In these terms, al-Jazari is a poet or at least a poet of automata.  In this respect, the discussion on price or maintenance misses the point completely because it treats poetry with traditional engineering tools.

Automaton of a slave pouring water and the Artuqid court


This is a slave made of jointed copper. In his outstretched right hand, he holds a pitcher decorated with a bird. His left hand is raised and in the palm is a towel, a mirror and a comb(not seen in the picture). This copper slave assists the king in Wuḍū – his ritual ablutions.  This is one of five chapters in the book where the King is mentioned explicitly. I went to learn a bit more about the Artuqids and the Palace in Diyarbakır.

Automaton of a slave pouring water, Topkapi manuscript, 1206.

 How did it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in siphons, floats, and pulleys can skip those bits. Essentially the mechanism is very similar to the Automatic Pitcher with a few additions, typical of al-Jazari. I modified the original drawing by al-Jazari and added captions to help follow the mechanism:

A modified drawing by al-Jazari with my captions, Topkapi manuscript, 1206.

In the beginning, a human servant removes the copper slave’s hat and pours water with a funnel into the water tank in the slave chest. In the drawing, the tank is half full. At the bottom of the tank, there is a rotary valve (in red). The servant brings the automaton to the King and rotates the hidden valve rod (in grey) near the neck. Water starts to flow through the pipe to the pitcher. There is a partition in the pitcher and the Pitcher spout, designed in the shape of a peacock’s neck, is a Siphon almost touching the partition. When the water rises they will block the airway through the spout, and the air only way out is through the whistle which will make a whistling sound. This is the part that was forgotten in the “Automatic Pitcher.” The siphon, spout, the partition, and even the rotary valve are identical to the “Automatic Pitcher”. The hand holding the pitcher is hardwired and will not move. The hand with the towel consists of an arm and forearm with an axis at the elbow and is free to move. The float is connected through the pulley to the elbow and would sink as the water exit, pulling the arm so that copper slave will offer the towel to the king.

For whom Al-Jazari designed his machines?

In the first chapter, “the Castel Water Clock” al-Jazari wrote :

” This is the basis of the work. Individual parts may be omitted or added according to the place for which it is constructed. For mosques and shrines it may be limited to what is necessary for telling the hours; for the palaces of kings, what may be fitting, such as pictures and other things.”

Naturally, I assumed that all al-Jazari machines were designed for the King and his court, after all, al-Jazari was the court engineer. But when I inspected the book carefully it turns out that the King was mentioned explicitly only in five chapters, including the current “Automaton of a slave pouring water” In only two chapters the  King is mention by his name King Salih, i.e. Salih Nasreddin Mahmud who ruled in Diyarbakir during the years 1200-1222. There are nine more chapters like Category VI chapter one, “the Palace Door” (only in Hebrew) or Category II, chapter four, ” A boat placed on a pool during a drinking party ” (also only in Hebrew) where the King is not mentioned, but from the description and the circumstances the machine was clearly designed for the Royal Court. There are thirty-six chapters which are machines with an unspecified designation. Nobody knows where the Elephant Clock or the Perpetual Flute were located at the time. They could be in the central square, the Palace itself or in some magnificent mosque. I don’t want to pretend that al-Jazari was an engineer in the service of the public. All he did was probably with the Artuqid King blessing. I set out to learn more about Artuqids and their court.

Artuqid kings

Al-Jazari had served three Artuqid kings. Only one of them is mentioned in the book by name: Salih Nasreddin Mahmud who ruled Diyarbakir 1200-1222.

Before him, al-Jazari served his brother Quṭb al-Dīn Sukmān II in the years  1185-1200 years, and he started his service in the Artuqid court for their father  Nūr al-Dīn Muḥammadin in 1181. All three are pretty minor figures in the history of the 12th and 13th centuries. Carole Hillenbrand, Professor Emeritus of History, University of Edinburgh wrote the book: “A Principality in Crusader Times Is: The Early Artuqid State” and several articles, but they contain mainly information about battles and alliances and less about the cultural life. I think if we remember the Artuqid is mainly due to its cultural enterprise. Twenty years or so before al-Jazari the Artuqid court hosted Usama Ibn Munkidh, a Muslim poet, author and knight who wrote كتاب الاعتبار‎ translated a to English as “The Book of Contemplation” which is probably the best-known Muslim source for the Crusader period. Upon the request of the Artuqid king, almost thirty years after the death of al-Jazari, al-Jawbari (الجوبري ) wrote “Book of Selected unveiling of Secrets.”This is a concise encyclopedia of tricks, practices, and devices used by fraudulent Ṣūfīs, false alchemists, jugglers, and quacks. To the best of my knowledge this was not translated to English (unfortunately!). You can add a new architectural language in Artuqid mosques explained in the Thesis of Sharon Talmor Sol(TAU) and Rachel Ward’s paper which present evidence for a workshop for copying manuscripts the Artuqid court. What was the cause of this cultural flourishing?

It is certainly not the size. The title “King” is perhaps a bit excessive. This is the map in the 12th century:

Map of the Principality of the Artuqids in 1200. Wikipedia.

The Artuqid Principality, as you can see, was tiny. Most of Turkey’s territory was controlled by the Byzantine Empire and the Sultanate of Rum. The later is what remained of the Seljuk Empire that controlled, at its prime, a vast area stretching from India to Antioch and from the Arabian Peninsula to Azerbaijan and contained most of the Muslim territories in Asia. However, by the 12th century, the Seljuk Empire was in decline, enabling the existence of small Principalities like the Artuqids. It’s not just the modest territory. Saladin, Sultan of Egypt and Syria, the founder of the Ayyubid dynasty in Cairo took Diyarbakir by storm in 1183 the Artuqids ruled by his grace. It is interesting to note that on the southern wall of the Palace in Diyarbakir appears الله اَلملك واحدي which means Allah is the ruler and drawing of Trebuchet. The Trebuchet is a powerful siege engine which uses a swinging arm to throw a projectile towards besieged city walls. In the second half of the 12th century, the Trebuchet was significantly improved, and those improvements appeared in a military manual written for Saladin. The drawing of the Trebuchet on the walls of Diyarbakir is unique, as far as I know. It can be interpreted as a quality assurance like “this wall would survive a barrage of Trebuchet” or it can be to commemorate the siege by Saladin as “Remember my siege and the horrendous Trebuchet I brought on your heads ” and maybe there is a different explanation altogether?

Picture of the Trebuchet on the southern wall of the fortress in Diyarbakir. Photographed by Lorenz Korn, 2008.

The historical information about the Artuqids doesn’t help me to understand or think about the book. There’s something very optimistic and perhaps even wonderful how this tiny Principality produced such a significant cultural-engineering heritage “It is impossible to overemphasize the importance of Al-Jazari’s work in the history of engineering, it provides a wealth of instructions for design, manufacture, and assembly of machines” Donald Hill in the History Engineering. From the foreword by Donald Hill.

I am adding two pictures of the Palace in Diyarbakir. This is the view from the palace of the  Valley of the Tigris. In Hebrew, the river is called ” Ḥîddeqel” following the ancient Akkadian name ” Idigina”. Most languages in the world follow the old Persian name, Tigrā:

Photo of the Tigris Valley view from the Palace.

Below is the Ulu Beden Tower, a black basalt stone tower in Diyarbakır. It was built in 1208, two years after the death of al-Jazari at age 70.

Ulu Beden Tower, Diyarbakir palace.

The double-headed eagle, the winged beasts and the beautiful Kufic inscription are, in my mind, related to the book. The double-headed eagle also appears on a coin of dirham minted by Mahmoud Nasreddin (the King of Al-Jazari):

A Dirham, 1218, minted in Ḥiṣn Kaifā where the Artukids court was before Diyarbakir.

Some claim that the double-headed Eagle is a Byzantine icon, and one head is facing Rome, and the other one is facing Constantinople. However, the double-headed Eagle symbolizes power and control from the time of Hittites and has countless appearances before and after Byzantium. Are the Tower, the currency, and the view of the Tigris valley helping you see al-Jazary at work? You decide.

The Mechanical Bartender, Cocktails and Rodeo


The official definition of a “cocktail” according to Webster Dictionary is “an iced drink of wine or distilled liquor mixed with flavoring ingredients.” However, we refer to almost any mixed drink as a cocktail. According to Wikipedia, the history of cocktails begins in 1806, but my readers will be surprised to learn that al-Jazari thought about it already in the 12th century. The drink-selector is a man riding a cow. To the best of my knowledge cows are not used in any culture for riding. The nearest exception is bull riding in the Rodeo, and the bulls look like they are not too happy with the idea. This post is a strange combination of all three (al-Jazari, Cocktail, and Rodeo). Let’s Hit the road.

The Wine pitcher, Manuscript from Syria 1315, Calligrapher: Farrukh ibn `Abd al-Latif

How does it work?

The technical explanation as always will be colored in blue, so anyone who is not interested in patents of pouring and extracting wine can skip those bits. Al-Jazari took a large brass pitcher and welded a handsome cow made from cast-bronze. In the center of the cow, there is a valve in the shape of a man riding the cow and his stretched hand points to a circular disk (not seen in the drawing). The pitcher is divided into five containers. In the first tank, there is an aromatic wine, in the second tank, there is a rose-colored wine(Rosé). The third has a yellow wine. I guess he meant what we call today white wine, but I could not find any support for my assumption. In the forth tank there is red wine, and the last one is full of water. The disk has each liquor markup:

Drawing of the disk, Topkapi manuscript, 1206

The rider is a sophisticated valve and when rotated to a point one get his chosen wine, or you can produce different mixes, and al-Jazari proposed a few options. The following drawing helps to understand how did it work. This is a combination of a drawing by the book translator and illustrator Donald Hill with a drawing by al-Jazari, and I added captions:

Integrated drawing of the book translator and annotator Donald Hill with a drawing by al-Jazari.

In the beginning, a servant lifts the cover and pours aromatic wine. The wine enters only the appropriate tank and fills it. The wine doesn’t get anywhere else (except maybe negligible amounts) because the way to the other containers is through the higher pipes. When the tank is full the float in the cage will rise and push the seal upward, blocking the tank. The purpose of the cage is to keep the float in place, allowing only vertical movement. I added the detailed drawing by al-Jazari how to build the cage for the float. Next, the servant would pour the Rosé. The wine will accumulate above the partition until it would pass the height of the pipe and flow into the Rosé tank. Since the pipe opening is lower from the bent in the siphon and the water pipe (please look in the drawing) and the white wine pipe (not in the drawing) No Rosé will flow into any other tank. Only when the Rosé tank is full, the float would seal it in the same way as explained before.  The same logic continues to fill all the remaining tanks. Each of the containers has a pipe which comes out of the cow mouth through the valve. When you turn the selector to one of the six points, the appropriate pipe is connected, and the selected wine comes out.


Cocktail is a drink prepared by mixing alcohol with alcohol or a soft drink. Al-Jazari proposed to mix all four wines, or to mix wine and water, half in half or third wine and two-thirds water. I think it falls under the definition of a cocktail. There is plenty of evidence for mixing alcoholic beverages throughout history but the first time it was mentioned explicitly by the name “cocktail” is in 1806 in the American magazine The Balance and Columbian Repository: “Cocktail is a stimulating liquor, composed of spirits of any kind, sugar, water, and bitters (alcoholic drink flavored with botanical matter).” I found the picture at the Museum of the American Cocktail in New Orleans (it’s not a Museum of my invention, and they even have an educational program?):

The newspaper where the term “cocktail” was first used.

The more interesting question is where this weird name cocktail = Rooster tail originated? One story is that the victor in a cockfight was toasted by his fellows with a special drink crowned with feathers, one for each of them left on the winning rooster’s tail. Another version claims that  Betsy Flanagan, a tavern keeper, served French soldiers a drink in 1779 garnished with tail feathers of her neighbor’s rooster. In other stories, the “Cocktail” has nothing to do with roosters but is a modification of some other word. Two options are: “Cocktail” was derived from the French term for egg cup, coquetel. One  Antoine Amedie Peychaud of New Orleans who mixed his Peychaud bitters into a stomach remedy served in a coquetel. Not all of Peychaud’s customers could pronounce the word, and it became known as a cocktail. The last story is that this was the name of a Mexican Princess named Xochitl. The name means flower in Aztec(?) and some claim it’s the name of an Aztec goddess. Either way, the princess served drinks to American soldiers as part of the celebration of a Peace Treaty signed between Mexico and the United States in the 18th century. “Cocktail” is just a wrong spelling of her name. There are plenty of other stories. The number of colorful stories makes me think they were invented in an evening of too many cocktails and I doubt them all.

It is interesting to note that the myth that drinking a cocktail or even mixing between various drinks (for example drinking beer with a shot of vodka) is the cause of drunkness, or at least a bad headache the next morning is just nonsense. Actual drunkenness and hangover are caused by the amount of alcohol and have nothing to do with mixing or the order of the drinks.


Al-Jazari doesn’t explain why the wine-selector is a man riding a cow? To my knowledge, there is no culture where people rode cows. Oxen were used regularly to pull heavy wagons or for grinding grains in mills and we have the wonderful Minoan art depicting acrobatics on bulls. We think it was a central part of Minoan worship, but to my understanding, we know very little:

The Bull-Leaping Fresco from the palace at Knossos.

The closest thing to riding cows is the Rodeo. It is a popular sport that originated in Spain and Mexico and spread to the United States and elsewhere. During the Rodeo, the rider must stay atop the bull for eight seconds with the use of one hand gripped on a bull rope and the other hand is in the air. I saw it only in the movies, and it’s a pretty sure way to end badly bruised or worse. It certainly doesn’t explain why al-Jazari chose the cow rider as the wine selector?

Cocktails are relatively sophisticated drinks and Rodeo, at least in my mind, is a much more popular sport that goes well with a beer or manly drinks.  To my surprise I  found that  there are quite a few cocktails associated with Rodeo, for example:

Two ounces of Reno Rodeo Legacy Vodka, juice from 1 lemon, 1-ounce triple sec, .5 ounce limoncello, and a splash of simple syrup to sweeten! Add all ingredients into a shaker with ice, shake vigorously, and pour into chilled martini glass. Let’s raise our glasses to al-Jazari, brave bull riders, and tasty cocktails!

Automatic Wuḍūʾ (الوضوء‎) Pitcher and Errors by Engineers


Al-Jazari opens this chapter with the wish of King Salih Nasreddin Mahmud, the third Artuqid king that al-Jazari was serving:

“King Salih disliked a servant or slave-girl pouring water on to his hands for him to perform his ritual ablutions and he wished me to make [something]for pouring water onto his hands for his ritual ablutions.”

The specific reference to ” a servant or slave-girl ” is a bit odd but al-Jazari responded to the challenge and made an “automatic” pitcher.

“Automatic” Pitcher, Topkapi manuscript, 1206.

A servant brings the pitcher and put it on a pedestal; it is a relatively large handsome pitcher. The duck whistles then the water begins to flow from the spout. There are quite a few whistling systems in al-Jazari designs, but this pitcher has no mechanism for the whistling which was probably forgotten. It made me look into error in the book and think about proofreading and editing.

How does it work?

The technical explanation, very minimal this time, will be colored in blue, so anyone who is not interested in siphons can skip those bits. Below is a drawing by the book translator and annotator Donald R. Hill that I edited and attached captions, all remaining errors are my own.

A drawing by the book translator and annotator Donald R. Hill


The pitcher is divided into two horizontally, the bottom part until the partition (orange al-Jazari original drawing) and top from the partition till the pitcher’s neck. The Pitcher spout, designed in the shape of a duck’s neck, is a Siphon almost touching the partition. A Siphon is a tube in an inverted ‘U’ shape, which causes a liquid to flow upward with no pump but powered by the pull of gravity. I wrote quite a bit on siphons, for example here. The atmospheric pressure pushes the liquid up in the tube only if the pipe is full of water. In the beginning, the servant pours water until the float submerges. The water level is too low, below the curve in the duck’s neck and no water will come out of the spout. The cover is also divided into two, and the top is separated from the bottom with a valve and a rotating plug. The servant pours water to the top part of the cover, put the pitcher on the pedestal and rotates the knob. The plug has a pipe through and when rotated will allow water down to the tipping bucket. The latter, when full will tip and release its water so the water level will rise into the neck and the ritual ablution begins. Al-Jazari wrote that the pitcher would whistle to notify the King that the purification is starting, but there is no indication, in the drawing or the text of a whistle. You should be aware that al-Jazari made frequent use of whistles based on compressed air and an intelligent engineer should not have difficulty to implement one here.


Errors and Proofreading

The missing whistle is not the only error in the book. For example, in the Elephant Water Clock al-Jazari writes that the two chains from the float upward connect to a single ring. This is clearly wrong because each chain is connected to another Dragon. There are probably more mistakes. Also, I’m just beginning to study Arabic and cannot detect errors in spelling or grammar.

The issue of errors in the text is on my mind because when I translate my post to English, I always find some errors in the original text. It can be minor typos, it can be real errors. Sometimes I think that mistakes (typing, proofreading, and essence) are like socks, whatever you’re doing, there’s always missing socks in the laundry, and unlike many pieces of advice online the socks are neither behind the washing machine nor inside the bed covers but simply disappeared forever. Despite the proofing, efforts and the goodwill there are always some individual errors that find their way into the text. My love M. read this text and told that the analogy is not working because socks disappear and errors remain. I think that in my head the two are connected because they are an impudent violation of the law of conservation of mass which states that for any closed system, the mass of the system must remain constant over time. Well, socks disappear, and errors appear from thin air.

I know some people are gifted editors or proofreaders, I think it takes a different set of characteristics than the qualities of good engineers. Obviously, a good editor who has deep knowledge of the language and understands the content can see what is clear and what is not and ask questions that help reveal errors. Engineers’ education does not emphasize the choice of words (what you say) nor style (how you say it) and writing quality, in general, is overlooked. Most engineers are more proficient in mathematical clarity rather than writing with clarity. The editor and the proofreader are naturally very skilled readers, and sometimes writers in their own right. There are certainly engineers who read literature although in my experience not that many. Additional attributes, required for an editor or the proofreader, are less obvious to me, and I don’t know how I can learn them. You need a great eye for errors. I read very fast, because of the ability to distinguish between what is important and what is less so. I’m not exactly flipping pages but I “correct” the text as I read and therefore ignore errors. I think patience in reading is required to see the existing version as well as alternative formulations. This is quite the opposite of the education of an engineer which is more directed to purposeful reading and extracting the meaning. Any good text needs a committed editor and meticulous proofreader. I certainly am not both, and I doubt they were available in Diyarbakir. If this is true no one need to wonder about errors the remained in al-Jazari’s book but to remove his hat in awe because they are so few of them.

The Monk Basin and Bloodletting


Bloodletting was common among many ancient cultures: Greece, Egypt, and Mesopotamia. Islamic medicine preserved and developed the medical knowledge of the classical period and the main traditions of Hippocrates, Galen, and others including the practice of bloodletting. Al-Jazari designed four apparatus for measuring the quantity of blood drawn. Al-Jazari devices are unprecedented and resemble water clocks and automata rather than medical tools.

The Monk Basin for measuring amount of blood during bloodletting.

How does it work?

The monk basin mechanism is quite similar to the mechanism of the Water Clock of the scribe. I bring the original drawing of the mechanism in parallel to the drawing made by Donald R. Hill, The book translator with my captions. The technical explanation, as always, will be colored in blue, so anyone who is not interested in pulleys or balancing weight can skip those bits.

The monk is standing in the center of the basin with a flat rim. He holds a staff in his hand pointing downward. The rim is numbered between 1 and 120 dirhams (درهم) about 360 milliliters. The monk is positioned on the main pulley which is attached to two ropes through two small pulleys. On one end there is a float and the other is attached to a balancing weight. Before the beginning of the bloodletting, two dirhams of water (approximately 6 milliliters) are poured for two purposes:

  • It wets the walls and reduces surface tension so that blood flows more smoothly
  • It sets the float to the starting point and zeros the staff position.

As bloodletting begins, the blood flows through the holes into the reservoir. As a result, the float goes up and releases rope through the pulley, the weight continues to pull down, and the large pulley rotates with the monk staff indicating the amount collected so far.



Bloodletting was a common medical treatment in ancient times, but it received substantial reinforcement from Galen, the Court physician of the Roman Emperor Marcus Aurelius. Galen’s understanding of anatomy and medicine was influenced by the then-current theory of humorism, also known as the four humors – black bile, yellow bile, blood, and phlegm.  Excess of black bile was understood to cause depression or melancholy. Phlegm, or mucus, was thought to be associated with a low level of energy and emotion, as preserved in the word “phlegmatic.” Yellow bile was connected to aggression, but Glen believed that blood is the dominant of the four. It was assumed to be produced exclusively by the liver and was associated with enthusiastic, active, and social nature. To balance one temperament or health, Galen created a complex system that showed how much blood must be shed, based on the patient’s age, status, season, and weather. He believed that “excess” blood symptoms are fever and a headache. Bloodletting location was specific to disease: vein or intravenously, close or far from the affected body part. As the problem was more serious, more blood was shed. High Fever demanded enormous amounts of bloodletting. Galen theories dominated Western medical science for more than 1,300 years. Understanding the function of the heart and the circulation of blood was obtained by surgery of cadavers in the 16th century. Amazingly it didn’t stop the practice of bloodletting till the 19th century when significant evidence regarding the damage caused by the procedure was accumulated.

It’s interesting that you can still find the remains of Galen theory in our language – for example, melancholy is literally “black bile” in Greek ((μελας, melas “black”, χολη, kholé “bile”).  In the medieval time, Islamic medical knowledge was the most advanced in the world, it combined the knowledge of the ancient Greek, Persian traditions and the ancient Indian tradition of Ayurveda. Rebirth of Western medicine was based mainly on texts in Arabic. In addition to preserving the knowledge, there were significant advancements including initial understanding, at least in part, of the blood circulation by Ibn al-Nafis which pre-dates William Harvey, by ~ four hundred years. It did not help to stop the bloodletting.

Maimonides, Rabbi Moshe Ben Maimon, beyond being the most prolific and influential Torah scholars of all generations, was an exceptional philosopher and physician who wrote (surprisingly?) about alcohol, exercise, and hygiene in a way that fits our current medical information. He did not reject bloodletting but added a few reservations, probably from his experience:

“A man should not accustom himself to let blood regularly, nor should he do so unless he is in great need of it. He should not let blood in hot days or rainy days but in Nisan ( a month on the Jewish the calendar ~ March-April) and a little in Tishrei (the first month of the Jewish year ~ September) and after fifty (years) will not let blood. One will not let blood and enter the bath on the same day, nor will he let blood and go on a journey or in the following day. He would eat and drink less than he is used to and rest at the day of bloodletting.”

Mishne Torah (I could not find a proper translation to English, so this is a literal translation by me)

Al-Jazari and Bloodletting

Two things jump immediately:

  • The first is the device choice. It seems it would be much easier to measure the blood in a bowl or a vessel with scale than the extravagant solution al-Jazari chose. The next post on the “Basin of the Two Scribes” will elaborate on this point.
  • The second point is the monk. The fact that a Muslim engineer chose a Christian monk surprised me.

To the best of my knowledge of Islam, as a rule, does not support abstinence and seclusion and considers it a sin. The multinational society in Diyarbakir in the 12th century included Christians, was it the responsibility of monks to let blood?

I could not find any direct information, but in 1163 the Church issued a church order which forbade monks and priests from bloodletting, claiming the Church despises (no less!) the procedure. It was part of a ban on scientific investigation, so we cannot suspect the Church of medical progress. Since a decree was warranted, we can assume that this was rather common and the al-Jazari’s device is reflecting that. In response to the order, the barbers began to offer a variety of medical services including bloodletting, pulling teeth and even surgical operations like amputations. It is hard to imagine a haircut or a shaving following a surgery. The pole with stripes that mark a barbershop even today:

The barbershop pole originated from the practice of bloodletting in medieval days. The top bowl represents a basin for leeches, where the bottom bowl represents the basin where blood was collected. The striped pattern is red for blood, white for the bandages and blue perhaps for the veins (?) The last part is not very convincing, but I did not find a better one. There are claims that barbers used to hang bloody towels or bleeding bandages on the pole