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.



A Goblet which arbitrates during drinking parties


It is a tall goblet made of silver. The goblet has a fretted, flat lid with a beautiful dome in the center. On top of the dome, there is a duck with an open beak. The goblet is put in the middle of the party, and wine is poured. The duck rotates and emits a shrill tone until it comes to rest and stops whistling; its beak is pointed towards one of the participants who drink from the spout and empties all the wine and returns it to the steward, If however, any wine remains in it the duck whistles and the steward would not accept the goblet until the chosen one completed the drinking.

A drawing of the Goblet which arbitrates, Topkapi Manuscript, 1206

How does it work?

The technical explanation will be colored in blue as always, so anyone who is not interested in how a pitcher of wine makes sounds and how you know how much wine was drank can skip those bits. The drawing below is by the book translator and annotator, Donald R.Hill. It would help us to follow the mechanism:

The goblet mechanism following the drawing by Donald Hill.

The servant pours the wine on the fretted lid. The wine flows downward through the opening on the water wheel. Please see below the beautiful drawing by al-Jazari, which looks just like a modern turbine of NASA. The flow of wine hits the blades and rotates the wheel and the duck, which is on the axle. The wine goes down into the channel into the goblet, driving the air from through the air pipe and the whistle. When the drinker drinks from the spout, the wine goes back in the opposite direction, but if the drinker did not finish the wine, it will come back and push air in the pipe, and the duck will make a sound indicating that the drinker did not complete his duty.

A comparison of the water Wheel by al-Jazari and a modern turbine, NASA website.



I am not an expert on Islam and its development, but the casual reference to alcohol drinking surprised me very much. I’ve explored the issue a little bit, but I would love to receive your corrections, comments, or other proposals. The prohibition on alcohol in the holy Quran is gradual. Muslims believe that Allah did so in his great wisdom and understanding of human nature and the knowledge of how rooted is alcohol consumption. In the beginning, Muslims were prohibited from participating in prayers when drunk:

Surah An-Nisa [4:43]:

“O you who have attained to faith! Do not attempt to pray while you are in a

state of drunkenness, [but wait] until you know what you are saying”

Further, it is said that alcohol is more damage than good:

Surah al-Baqarah 2:219:

“They will ask thee about intoxicants and games of chance. Say: “In both there is great evil as well as some benefit for man; but the evil which they cause is greater than the benefit which they bring.”

And only, at last, there is a sweeping prohibition:

Surah Al-Maida, 5:90

“O you who have attained to faith! Intoxicants, and games of chance, and idolatrous practices, and the divining of the future are but a loathsome evil of Satan’s doing: shun it, then, so that you might attain to a happy state!

All English translation by Muhammad Asad.

Despite the prohibition on drinking wine and intoxicating beverages in Islam, you can find many testimonies for drinking alcohol in the medieval Islamic world in language, culture, and poetry.  The word “alcohol” itself comes from the Arabic word al-kuhul (الْكُحْل) means the essence. This is because the production process is reminiscent of the production of the Kahal powder used as a dark eye-coloring cosmetic. In poetry, Abu Nuwas, probably the most famous Arab poet of the Abbasid era who also appears in “Thousand Nights and Nights,” wrote wine poems, The Khamriyyāt. You can be read more here:

“Don’t cry for Layla, don’t rave about Hind!

But drink among roses a rose-red wine,

A drought that descends in the drinker’s throat,

bestowing its redness on eyes and cheeks.

The wine is a ruby, the glass is a pearl,

served by the hand of a slim-fingered girl,

Who serves you the wine from her hand, and wine

from her mouth — doubly drunk, for sure, will you be!”

The Story of Bayad and Riyad, 13th-century Manuscript, Vatican library

“The drawing is from the manuscript “The Story of Bayad and Riyad”( حديث بياض ورياض).  This is the only manuscript left; it was probably created in Andalusia very close to 1200 (the years in which al-Jazari wrote “The Book of knowledge of Ingenious mechanical devices”) The scene in the picture is clearly a feast in which a group of women and men drink wine together.

The goblet which arbitrates is evidence that the court of Diyarbakir has lived with this contradiction in peace. There are plenty of references to Islam and its customs in the book, and there are playful fun drinking parties without any apology or concealment. We only have to guess the explanation. The Arctic rulers lived among a diverse local population, including Armenians, Syrians, and Greeks, most of them oriental Christians. In Christianity, not only wine is not forbidden, but it is a part of the ritual. At the Last Supper of Jesus, Jesus blesses the wine, states that the wine is his blood, and instructs the disciples to drink from it. Then he passed unleavened bread around the table and explained to his Apostles that the bread represents his body. These are the roots of the Holy Communion ceremony. It is possible that living together led to a softer approach to drinking wine. However, the evidence for alcohol use comes from all over the Muslim world from Persia to Andalusia and also spans for hundreds of years. I may be dumping the strict current prohibition on periods where the perception of early and late in the holy Quran was different and religious concepts were more moderate.

Truth or Dare?

My beloved M., the first reader of my posts, commented on the resemblance between the rotating duck and the bottle in the game “Truth or Dare”. This is a party game I last played as a teenager and was particularly popular among adolescents. The Internet offers application (few!), which make me feel that what was daring at my time is quite innocent today. On the other hand, it seems as though the game is still popular and therefore needs have not really changed?

Seemingly, this is a different game. The participants sit in a circle and spin a bottle. The participant to whom the bottle was pointed was asked: “Truth or Dare?” If you choose “truth”, you are asked a question that you must answer. At the time, all the questions were opened in: “Is it true that…” And most of them, if not all, dealt with things that are between him and her. If you choose “Dare”, you are given a task that opens with words “I dare you..” and most of those were the first kisses or something ridiculous. The question I think is why we need a bottle? Or in the context of the goblet which arbitrate why in duck?  Adolescents, at least in my time, were embarrassed about discovering their sexuality and the relationship with the opposite sex. The use of a game frame and temporary loss of control for the benefit of the “bottle” allowed expanding the boundaries and experimenting with what was difficult to ask or say without the protection of the game and could bring about embarrassment or reprimand. Does this mean that the partners at the banquet needed a duck that arbitrates because they felt discomfort with drinking alcohol? is this a question mark on my assumption that the goblet is clear evidence that the court of Diyarbakir lived with this contradiction in peace?

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 Water Clock of the Boat, a Serpent or a Dragon?


The boat clock is a simpler version of the elephant clock. The scribe indicates the minutes passed and one Dragon (two in the elephant clock) swinging on its axis every half an hour. It looks like an early sketch for the elephant clock or a simpler version for beginners. Perhaps, for this reason, nobody wrote, or at least I haven’t found anything nor restorations or animations in contrast to the abundance for the elephant clock. The Dragon appears here in more detail and also has a drawing of his own but the text refers to it as a serpent just with legs and wings, it got me thinking about the biblical serpent and the story of the tree of the knowledge of good and evil. This post is dedicated to the serpent-dragon, and on this occasion, I also explain the balancing process which allows the dragon to go for a marvelous swing and return safely on his legs.

The Boat Clock, Topkapi manuscript, 1206.

How does the dragon make a flip and Lands on his feet?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in submersible floats or torque and center of mass can skip those bits. In the water clock of the boat, like the elephant clock, the main mechanism is a sinking float, a float with a hole which sinks slowly during half an hour. After half an hour the float is full of water and begins to sink quickly and releases a ball that falls into the dragon’s mouth:

Drawing from the book, Topkapi manuscript, I tilted the dragon to visualize the swing and added the lead weights in his tail and the ball.

The dragon is made of a thin brass plate which was rolled to a pipe and hammered to form the shape of a dragon. The dimensions are not very detailed, but the Dragon’s tail forms a circular ring of four fingers, or 8 cm, diameter. The dragon head is hammered separately and soldered to the ring. The Dragon’s legs are holding an axle which is free to rotate. The ball I added does not appear in the original drawing, but is described in the text and weighs 30 dirhams (درهم), almost 100 grams. When it falls into the Dragon’s mouth, it generates a torque causing the dragon to flip. A torque or moment of force is the rotational equivalent of linear force. The torque is given by the cross product of the position vector (distance vector) and the force vector:

Some of the students I taught physics during the years struggle with cross products and especially with the moment of force. But we all know intuitively that it is easier to open the door by pushing it near the handle than push it near the hinges.(larger r =larger torque). Or when we struggle to remove the lug nuts of a flat wheel, we often use a wrench extension for the same reason – to generate a larger torque.

When the dragon’s head is downwards, the ball falls off, and the lead weight in his tail exert torque in the opposite direction and reset the Dragon position. My love M.  said that the dragon is like a roly-poly and of course she is correct. This is a round-bottomed toy, usually egg-shaped, that tends to right itself when pushed at an angle, and does this in a seeming contradiction to the force of gravity.

Drawing of a roly-poly

The bottom of the toy is made of a high-density material such as metal, and thus the center of mass is low relative to the height of the toy. This is very similar to the lead weights in the tail of the dragon. The ball falls into the Dragon’s mouth function as the finger pushing the toy over. In both cases, the low center of mass exerts a torque that reinstates the upright orientation.

Interestingly enough al-Jazari calls the lead “black lead” (الرصاص اسود) because in his time they called Tin “white lead”. Maybe in a future post, I will write more about the metallurgy of the 12th century.

A Serpent or a Dragon?

Serpentes (snakes) are an elongated, legless, carnivorous suborder of reptiles. They are characterized by the absence of limbs. Al-Jazari serpent has wings and legs making it a legendary creature or a Dragon. Dragons do not exist (sorry if I offended the fans of dragons) and respectively do not have a rigid biological definition. A dragon is a large, serpent-like mythological creature that appears in the folklore of many cultures around the world. Beliefs about dragons vary significantly by region, so horns wings and the number of legs vary a lot. All dragons have superpowers. We are more aware dragons capable of breathing fire in the western cultures but Bakunawa, a dragon from the Philippines, can swallow the moon, and the Vietnamese dragon can control the weather. It can be argued that the Dragon figure was influenced by various snakes, especially spitting cobras, bats (wings) and giant lizards and in the modern era extinct dinosaurs. In the Wikipedia entry of the “Elephant clock” appears this wonderful quote in the name of al-Jazari signifying his “multicultural mentality”:

  “The elephant represents the Indian and African cultures, the two dragons represent Chinese culture, the phoenix represents Persian culture, the water work represents Greek culture, and the turban represents Islamic culture.”

Al-Jazari didn’t write these lines. Such errors are amazing and funny and are one of the risks of a free-content encyclopedia relying on volunteers editors.

In contrast to the threatening figure of the Western Dragon, Chinese Dragon is a symbol of strength, integrity, and wisdom. The Chinese Dragon is depicted as a lizard-like creature without wings and four clawed feet and long tendril appended to each side of the snout. Al-Jazari’s Dragon is not very Chinese. However, at home, we have a facsimile edition of the Sarajevo Haggadah.” It’s Passover Haggadah written in Barcelona around 1350, and it is considered to be the oldest surviving Haggadah. The Haggadah is displayed at the National Museum of Bosnia and Herzegovina in Sarajevo, and this is the origin of its name. To my surprise, the Haggadah is packed with dragons. On top of this, in the 19th century in Paris, a small book was printed: – L’ornementation des Moyen-âge. This is a collection of illustration from medieval manuscripts and also includes many dragons. The dragons in all three books are very similar, the same general, lizard-like structure, the same animal head which is not completely defined, small wings and legs. If my rationality hadn’t so constrained me, I would be convinced that the three illustrators visited some mysterious zoo and made a drawing of the dragon that was held not far from the reptile room.

Right side dragons from Haggadah Sarajevo, in the center the Dragon of the Boat, Topkapi manuscript and to the left a dragon from L’ornementation des manuscrits au Moyen-âge

All this discussion about snakes with legs took me back to the Bible story, Genesis 2-3.  Adam and Eve were in the garden of Eden, where “And out of the ground made the Lord God to grow every tree that is pleasant to the sight, and good for food; the tree of life also in the midst of the garden, and the tree of knowledge of good and evil.” God allowed Adam and Eve to enjoy the fruits of the Garden except for the tree of knowledge, “for in the day that thou eatest thereof thou shalt surely die. Now the serpent was more subtil than any beast of the field which the Lord God had made” The Serpent Tempted Eve claiming “then your eyes shall be opened, and ye shall be as gods, knowing good and evil.” Therefore the snake lost its legs and got in trouble with men kind: “And the Lord God said unto the serpent, Because thou hast done this, thou art cursed above all cattle, and above every beast of the field; upon thy belly shalt thou go, and dust shalt thou eat all the days of thy life:

Genesis 2-3 King James Version

But did al-Jazari know the Biblical story about how the ancient serpent lost his feet?

Years ago I visited the Topkapi Museum in Istanbul, and near one of the swords there was a summary of the “The Binding הָעֲקֵידָה Ha-Aqedah” only, Ishmael (and not Isac) is the victim and the hero of the story. First, I thought there was a confusion, but this is of course just my ignorance. Eid al-Adha ( عيد الأضحى‎) ‘Feast of the Sacrifice’ is the second of two Islamic holidays celebrated worldwide each year. The sacrifice celebrated is the sacrifice Ibrahim (Abraham) our father, was asked by God to sacrifice his son Ismail (Ishmael) though the Qur’an does not name the son. In my eyes, both stories are equally heinous, and already as a child, I remember my inner resistance. Like the story of the Binding, the story of the garden of Eden in the Quran is completely different:

“And you, Adam, inhabit the Garden, you and your wife, and eat whatever you wish; but do not approach this tree, lest you become sinners.

But Satan whispered to them, to reveal to them their nakedness, which was invisible to them. He said, “Your Lord has only forbidden you this tree, lest you become angels, or become immortals.”

Quran, Surah 7 elevation, Translated by Talal Itani.

In the Quran, there is no tree of knowledge. The only tree mentioned by name is the Tree of Immortality ( شجرة الخلود Shajarat al-Kholoud ) The Serpent is not the seducer but the devil himself, and he is tempting Adam and Eve with eternal life. In Surah 2, The Heifer, appears Iblis (إبليس), which is another name for the devil in Islam. Eve, as a woman, is the main guilty in the original sin, both in Judaism and Christianity. In Islam Eve is Adams’ partner and clean from sin.  It is very unlikely that al-Jazari didn’t know the Serpent from the story of the creation and knew only the Quran version and the source of the legs and wings who can tell?


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


Formulas are holy and the automaton of a standing slave holding a Fish and A Goblet

“Troubles overcome are good to tell” – “Ibergekumene tsores iz gut tsu dertsyln.” Yiddish proverb by Primo Levi, “Periodic Table


The automaton is one of the simpler al-Jazari’s designs, but the description, like many other descriptions in the book, is intriguing not to say mesmerizing.

“He is a standing slave, ten years old in appearance, dressed in a short jacket with a rob underneath it, and a cap on his head. In his right hand is a glass the fingers curled around the bottom of the glass so that it can be taken out of his hand and put back… His left hand is in the same position, but higher than the glass, and holds a silver fish.”

Drawing of the Automaton with the fish and the goblet, Topkapi, 1206

The fish is surprising.  As far as I know, the fish is a Christian symbol, because of the miracle of the five loaves and two fish, because fishermen like Simon, Peter, Andrew, and John were the followers of Jesus later to become the apostles. Ichthus (Greek ΙΧΘΥΣ) the fish symbol is an acronym for Iēsous Christos, Theou, Yios, Sōtēr; in English:”Jesus Christ the son of God, Savior” has become a sign of recognition among persecuted Christians. The connection between wine and fish reminded me of a fascinating conversation between in varnish makers in the story “Chromium”  from the book “The Periodic Table”  written by Primo Levi; I will elaborate below.

How does it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in copper hammering or tipping bucket can skip those bits.

This chapter has only one drawing, the one that appears above. Perhaps because this automaton is so simple. On the other hand, there are detailed explanations on the fabrication process:

“If the craftsman is not competent enough to make the face by hammering he can make [various] parts thicker with lead, e.g. the nose, etc.”


“The craftsman should not be afraid that the slave will tilt in any direction. I made him and placed the soles of the feet on the ground, and was afraid that he would tilt, but when he was standing erect he did not tilt at all.”

I took the liberty to take the original drawing of  al-Jazari and make it more like a contemporary drawing which clarifies the mechanism of the automaton:

The mechanism of the automaton, a slave with a goblet and a fish. My drawing

The upper part of the automaton, the head, and the chest is a wine reservoir. Its filling opening is hidden under the cap of the slave. At the bottom of the reservoir, there is a small drain above a tipping bucket. Al-Jazari often used tipping buckets. We met them already here (Hebrew), and we will meet more in future posts. Initially, the tipping bucket is leveled, as shown in the drawing, but after seven and a half minutes it is filled with wine towards its tip, and the bucket tilts and discharges all the wine through the pipe to the hollow silver fish. The silver fish is mounted on an axle, and its lower part is slightly heavier, so the fish is tilted upwards. With the wine,  the fish head becomes heavier and sinks until it is near the goblet and the wine flows into the goblet. Under the weight of the wine, the arm of the slave descends as if he were offering the glass to the king. The king takes the glass, drinks from it, and returns it to his hand, which has risen to its previous position. This repeats every seven and half minute intervals until the reservoir is empty.

“Chromium” by Primo Levi or removing the onion from the varnish

Primo Levi, a wonderful Italian author, his best-known works are related to his personal life story as a Holocaust survivor like “If This Is Man”, “The Truce” and others, but I particularly like the “The Periodic Table”. In my defense I am (also) a chemist  and Primo Levi himself wrote:

“I write because I am a chemist. My trade has provided my raw material, the nucleus to which things join … Chemistry is a struggle with matter, a masterpiece of rationality, an existential parable … Chemistry teaches vigilance combined with reason.”

Many of my students of chemistry, physics and computational science, to their surprise I should  say, heard me over the years reading the story “Chromium” from “The Periodic Table” which opens:

“The entrée was fish, but the wine was red. Versino, head of maintenance, said that it was all a lot of nonsense, provided the wine and fish were good; he was certain that the majority of those who upheld the orthodox view could not, blindfolded, have distinguished a glass of white wine from a glass of red… Old man Cometto added that life is full of customs whose roots can no longer be traced… I made a rapid mental review to be sure that none of those present had as yet heard it, then I started to tell the story of the onion in the boiled linseed oil. This dining room, in fact, belonged to a company of varnish manufacturers. “

The story begins in a prescription book for varnish. Advice is given to introduce into the boiling oil two slices of onion, without explanation or purpose and ends with ammonium chloride in a chromate-based anti-rust paint. For those who do not speak “chemistry” as a native language both are absurd. The weird and wonderful story is the essence of what is science and technology. I will explain the story of the onion, briefly but one who wants really to indulge in the story should read “The Periodic Table”. The onion was inserted into the oil before thermometers were used. When the onion started frying it indicated the proper temperature was reached and it is time to end the boiling process. Over the years varnish manufacturers switch to thermometers but forgot the original reason for using the onion and did not dare to deviate from the recipe they knew. This is how the recipe found its way to the book. When I read about the automaton of al-Jazari, I remembered this conversation and was wondering if they drank from the fish white or red wine?  What do we know about the drinking habits in the twelfth century? Apparently quite a bit.

Drinking habits in the twelfth century

For many years diners were isolated from wine drinking sessions. In ancient Greece, the Symposium (Greek: συμπίνειν, = to drink together) was a feast which took place after dinner. Drinking for pleasure was accompanied by music, dancing, or a good conversation. The modern use of symposium as an academic scholarly discussion is quite different. Although the Romans drank during dinner, wine mixed with water, they had a separate drinking party (comissatio) after dinner. Similarly, Arabic-Islamic culture in the middle ages enjoyed wine only after finishing the meal. In the chapter on alcohol consumption in medieval Cairo, Paulina Lewicka, from Warsaw University, wrote about drinking sessions called majlis al khmar (الخمر مجلس) literally the wine council. The second category of “The Book of Knowledge of Ingenious Mechanical Devices ” is dedicated to “Vessels and Figures Suitable for Drinking Sessions.” In all ten chapter, every chapter covers one device there is not a single meal. It seems that in the palace in Diyarbakir the meals were separated from drinking parties. This makes the question which wine goes with a fish irrelevant. It is still interesting to know what kind of wine they’re drinking? In the chapter of the automaton of the slave holding a fish and a goblet, it  “clarified wine” (sharab murawwaq) is mentioned. “Clarification” is the processes by which insoluble matter, like dead yeast cells, or various tannins, is removed before bottling, thus improving the wine quality and taste. Today this is part of the standard process, and this tells me very little about the actual wine they drank. In 1169 Saladin, already mentioned, became a Vizier in Cairo. He repented wine-drinking and turned from frivolity to religious life and later prohibited drinking alcoholic beverages altogether. Although the Artuqid ruler were vassals to Saladin, the prohibition was not implemented in Diyarbakir. In Cairo things were not simple either. While I was looking for information about wine drinking in this period, I found Firuzabadi’s “Wine-List.” This manuscript from the British Museum’s collections originated in 15th century Cairo. The author is careful to emphasize that he composed it in loyal support of the prohibition. By accident or intention the sub title is quite ironic: “The Cheery Companion, on the prohibition of old wine”  Then he alphabetically names 357 (!). The majority are very descriptive, ” the golden “,  “cock’s eye”, “mother of vice” and  even ‘the one which is drunken in the morning.” Even though it is difficult to know how similar or different the wines in Diyarbakir were in comparison to what we drink, we can conclude that in Diyarbakır palace they probably had a fine selection of wines.

The passing of time and great truths

Back to Primo Levi; The use of oil of Sandarac, a varnish obtained from the small cypress-like tree appears many times in the “Book of  Knowledge of Ingenious  Mechanical Devices “. The idea of using onions to evaluate the temperature of the oil was certainly within reach of al-Jazari. Perhaps he would have enjoyed the story about the onion in the recipe even after precise thermometers were used. The story of the ammonium chloride was probably incomprehensible for him. First chromium was discovered in 1797 by the French chemist Louis-Nicholas Vauquelin, and the use of chromium in the paint industry would be strange. Secondly the “detective story” is based on chemistry that he could not know; Elements, Atoms, Acids and Bases belong to the future, centuries after his time. However, I think he would sympathize with the sweet sensations felt by Primo Levi (details in the story!) when he understood that ammonium chloride the formula is the result of his own work two decades ago. He wrote:

“But formulas are holy as prayers, decree-laws, and dead languages, and not an iota in them can be changed. And so my ammonium chloride by now completely useless and a bit harmful, is religiously ground into the chromate anti-rust paint on the shores of that lake, and nobody knows why anymore.”

The Perpetual Flute and al-Jazari’s Library


The Book of Knowledge of Ingenious Mechanical Devices contains quite a few musical automatons. Some of them such as the musical boat we have already met in previous posts, others such as the world’s first drum machine, we will meet in a future post. The fourth category deals mainly with fountains, but there are also four perpetual flutes, which use the flow of water to compress the air through a flute thus replacing the flautist. Al-Jazari specified three sources for his works, Apollonius the Indian carpenter, a drawing from an unknown source, and a work by the eminent inventor, Hibat Alla Husayn al Astrurlabi. It made me wonder about his library.

Figure 1 The perpetual flute, scattered pages (copy from 1315) (Metropolitan Museum, New York)

How does the flute work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in the tilting pipes and floats can skip those bits. This is a drawing from the book, and I added labels for clarity.

Figure 2 The perpetual flute (1206). Topkapi manuscript (with added labels)

There is a constant water supply to the perpetual flute. The water flows into the bowl welded to a transverse pipe that can be tilted (tilting pipe). The pipe is slightly heavier on the side of tank A, and the water thus flows into that tank. The air is pushed out, and the only way is through flute A, so a sound is heard. Although it is called a ‘flute’, it is more like a whistle as the pitch cannot be changed, and there is no parallel for different fingering producing different notes. At the same time, plug B is pulled out, thus emptying tank B. The water will continue to flow into tank A and float A will rise with it. At some point, float  A will push the tilting pipe upward, and shift the water flow to tank B. The water will rise in tank B  and the only route for the air will be through flute B. This process repeats itself as long as the waters supply continues.


The literature survey and al-Jazari’s Library

Any research or technology development project starts with a literature survey. Students, especially in the early stages of their training in science or technology, feel that the survey is tedious, and perhaps a formality and not helpful. But in time they will learn that the survey is needed to map the current information available and is essential from the very early stages of understanding the theory and developing the methodology until the final stage of writing the paper, the patent request or the research report. Modern scientific disciplines emerged centuries after al-Jazari. I do not know if literature surveys were the norm in early scientific papers. Was al-Jazari a precursor in using them or is he following a known path? In previous posts, we saw references, and a critique of the work of Archimedes and the Banu Musa. But in this chapter three resources are mentioned:

  • “I came across a well-known paper by Apollonius, the Indian carpenter: he made a wheel which turns slowly and opens water outlets…”
  • “I also examined another old instrument, about which I found no written report, but a drawing. In this, the flute is like a nay having eight holes”.
  • “I [also] examined a paper written in Baghdad in year 517 A.H. by the eminent inventor Hibat Allah al-Husayn al-Asturlibl, in which he makes a real innovation….”

Figure 3 Treatise on the Design and Construction of a Hydraulic Flute Playing Machine. Attributed to ‘Apollonius the Carpenter and Geometer’ (sixteenth century) (British Library: Oriental Manuscripts)

In the next post about the perpetual flute with two tipping buckets, I hope to elaborate on these early works and what survived the hundreds of years that passed. However, the fact that al-Jazari had three different sources for the perpetual flute made me think that he had quite an impressive library. Was this the Diyarbakir Palace Library? In the library, were there shelves dedicated to engineering and technology? Who else was reading these books? Maybe these books were in his workshop? Manuscripts were done by hand and required a lot of careful writing and drawing. The price of a manuscript must have been very high, so how would it have been possible? I wish we had answers to all these questions, but we do not. However, some more general information is available.


Manuscripts and libraries in the golden age of Islam

Paper was invented in ancient China. Legend says that two Chinese prisoners captured by the Abbasid Empire after the victory in the Battle of Talas (Kyrgyzstan) in 751, revealed the secrets of paper making. I do not know if this true or not, but there is enough historical evidence for a dramatic paper revolution in the Muslim world in the ninth and the tenth century. In Baghdad, the Chinese art of paper making was improved and mechanized. Linen and rags replaced the traditional mulberry tree bark as raw material. The use of water-powered or animal-powered mills for preparing the pulp helped in transforming paper-making into an industry. The Muslims also introduced the use of trip hammers. The producers in Baghdad and Syria became the main suppliers of paper to Europe. Paper became cheaper and of better quality. The Islamic culture in the Middle Ages, which originally had higher literacy rates, certainly in comparison to Europe, was becoming a leader in sophisticated book production processes, flourishing book markets and rich libraries. All this resulted in a dramatic increase in the availability of books and their accessibility to various segments of the population.

The adoption and industrialization of paper-making is the opposite of the Ottoman Empire’s refusal to embrace Gutenberg’s printing press revolution. It requires another post, but until the eighteenth century, the Turks allowed only non-Muslims, especially Jews, to print. Two revolutions: paper was adopted and the printing press was rejected, both extreme examples of how technology affects culture and society and how seemingly technological decisions can change society.

We know quite a lot about libraries in the Muslim world. The first of which is the House of Wisdom ((بيت الحكمة‎;) founded by Harun al-Rashid, the fifth Abbasid Caliph in Baghdad and the House of Knowledge ((دار العلم) established by Al-Hakim bi-Amr Allah, sixth Fatimid Caliph in Cairo. The two libraries were centers of Islamic learning of the Qur’an and Hadith, philosophy and astronomy. The Fatimid historian Al-Musabbihi wrote:

into this house, they brought all the books that [the Caliph] ordered to be brought there, that is, all the manuscripts in all the domains of science and culture, to an extent to which they had never been brought together for a prince. He allowed access to all this to people from all walks of life, whether they wanted to read books or dip into them… He granted substantial salaries to all those who were appointed by him there to do service, jurists and others… He also donated what people need: ink, writing reeds, paper, and inkstands”.

Figure 4 Scholars in the Library in Baghdad, illustration by Al-Wasiti (1237)

There are fantastic stories about the size and richness of these libraries. For example, it is said that during the Mongol siege of Baghdad in 1258 AD, the House of Wisdom was destroyed. The books were thrown into the Tigris River in such quantities that the river was black with the ink. Nasir al-Din al-Tusi rescued about 400,000 manuscripts which he took to Maragheh before the siege. The closest I came to Al-Jazari’s library was a short remark in the diaries of Carl Süssheim. He was an Islamic historian and orientalist. In his diaries, he tells a story about Emiri Efendi who sold him precious manuscripts. According to Emiri Efendi, Saladin, founder of the Ayyubid dynasty who defeated the Crusaders at the decisive Battle of Karney Hattin, “scattered the library in Diyarbakir which contained millions of volumes”. I could not find any other reference to support this. All this information makes manuscripts more accessible than I originally thought, but I still wonder what al-Jazari’s library looked like.