Diyarbakir

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The clock of the doors and the Jewish question

Introduction

The clock of the doors is identical to the candle clock of the monkey in terms of its mechanism and does not warrant a separate post. Just like the old joke about “The Elephant and the Jewish Question,” the clock of the doors has nothing to do with Jews,  which are not mentioned in the “The Book of Knowledge of Ingenious Mechanical Devices” even once. The phrase “The Elephant and the Jewish Question” is usually used to describe an annoying person who tries to link any event, however universal, to the Jewish people and their problems. I hope I’m not one of them, and I don’t have any convincing reason why I went out to check what we know about the Jews of Diyarbakır and Anatolia in the 12th Century. However, what I discovered is strange and exciting, and maybe it will interest you too.

The Candle Clock of the Doors” The Book of Knowledge of Ingenious Mechanical Devices, “Topkapi manuscript, 1206

How does it work?

Al-Jazari himself wrote:

” It is like the previous model, from which nothing is omitted except the keeper and the monkey. The additions are as follows: around the perimeter of the candle holder, fourteen doors are erected, each with two leaves. When a constant hour has passed from the lighting of the wick, a ball falls from the falcon’s beak, and the door opposite the falcon opens, and a figure emerges, [made] according to the choice of the craftsman.”

Anyone interested in the mechanism can go back and read my explanation of the monkey clock or the candle clock of the scribe. I will briefly explain the opening of the doors.

During combustion, the candle will shorten, and the force exerted by the weight will push the candle mount upwards at a constant rate that depends on the rate of combustion. To the bottom of the weight is attached another wire that runs over the pulley on which the bracket sits with 14 doors. These rotate as the candle burns. When the ball falls, it pushes the figure who opens a door and represents the time that has passed. This process repeats itself every hour.

The Jews in the 12th Century

The history of the Jewish people in the 12th Century is not similar in Ashkenazi communities and Muslim Spain. In Europe, the 12th Century began with the Rhineland massacres, a series of mass murders of Jews perpetrated by mobs of the People’s Crusade in 1096. The communities on the Rhine (Speyer, Worms, and Mainz) were destroyed. In 1146, in a repeat of the events of 1096, Crusaders preparing for the Second Crusade attacked and massacred Jewish communities along the Rhine. The 12th Century more or less ended with One of the worst Jews massacres of the Middle Ages, which took place in York in 1190. An angry mob trapped the city’s entire Jewish community inside the tower of York Castle. Many members of the community chose to commit suicide rather than be murdered or forcibly baptized by the attackers.

In Spain, on the other hand, Jewish people under Muslim rule experienced tolerance and integration. Some historians refer to this period as the “Golden Age” for the Jews, as more opportunities became available to them. That lasted from the days of the Caliphate of Cordoba to the small independent Muslim principalities and kingdoms of the Iberian Peninsula known as “taifas” and the process of the reconquest of Spain by the Christians. Social integration allowed Jews to advance significantly in new fields, philosophy and science. Some of them wrote poetry, primarily Hebrew poetry. They wrote about everything: poems about Zion and the people of Israel, but also poems about wine and women. I don’t think there’s a connection between the cultural flourishing in Diyarbakır and the Jewish flourishing in Muslim Spain, but it’s still intriguing. The Golden Age began in the 9th Century and ended in the 13th Century, but some of the more familiar figures were almost parallel to al-Jazari. For example, Maimonides was born in Cordoba in 1138, two years after al-Jazari, and died in Cairo in 1204, two years before him. Maimonides is a true polymath: one of the most prolific and influential Torah scholars of all generations, as well as a prominent philosopher of the Middle Ages, a scientist, and a physician. In his thirst for wisdom, he formed a study group and a friendship with Jabir ibn Aflah (a Muslim scholar) ‘s son, and they studied mathematics, medicine, and philosophy together. This must sound strange to those who live in Israel today and are familiar with the ultra-Orthodox opposition to secular studies. The “Kuzari” book, ” Book of Refutation and Proof on Behalf of the Despised Religion,” which I still managed to study in high school, was written by Rabbi Yehuda Halevi in this Century, and I must mention Rabbi Abraham Ibn Ezra, a 12-century poet, linguist, biblical commentator, and philosopher. He also worked in mathematics and astronomy. One of the lunar craters is named after him. Ibn Ezra’s most important mathematical work is in Hebrew: “The Book of the Unit,” which deals extensively with the decimal system and how it is used, thus preceding Fibonacci, the main contributor to the spread of this method in the Western world.

Did al-Jazari know the books they wrote or even heard about them? It is impossible to know, but the likelihood is extremely low.

Jews in Diyarbakır

In 1518, the Ottoman government conducted a census. There were 28 Jewish families and three single men in Diyarbakır. These are the first definitive data we have. After that, a continuous Jewish presence peaked in 1905, but apparently, the presence of Jews in Anatolia predates the Muslim conquest. According to traditions held by the Jews of Kurdistan, the Jews arrived in Kurdistan as early as the Salomon’s Temple period and are descendants of the Ten Tribes. As written in the book of  Kings:

” In the ninth year of Hoshea, the king of Assyria took Samaria, and carried Israel away unto Assyria, and placed them in Halah, and in Habor, on the river of Gozan, and in the cities of the Medes.”

Although we do not have a complete geographical identification, the name “Habur” has been preserved to this day as one of the Tigris tributaries located near the city of Zaxo (Arabic: زاخو), about 300 km from Diyarbakir. Later exiles to Babylon by Nebuchadnezzar, King of Babylon from the Kingdom of Judah, joined them. So it is very likely that there were Jews in Diyarbakir in al-Jazari’s day.

A Jewish delegation meeting with an Ottoman official

The Strange Story of David Alroy

Alroy was born a year before al-Jazari in Amadiya, Kurdistan. At first, I was confused because the historical name of Diyarbakır is Amida, but these are two different cities. Amadiya is located in northern Iraq, about 400 km southeast of Diyarbakir. David Alroy studied rabbinical literature with Hasdai, the exilarch, the leader of the Jewish community in Persian Mesopotamia, and Ali Gaon, the head of the Sanhedrin,  an assembly of elders appointed to sit as a tribunal in Baghdad. There is a claim that he was also well-versed in all the Books of Magic and sorcerers. I’m not sure what books are included, but it’s a bit like Chekhov’s gun, which appears in the first act, firing in the third. I have already mentioned Benjamin of Tudela, and not for the better. He wrote:

” David Alroy took upon him to rebel against the King of Persia [in 1163] ; for which purpose he gathered together all the Jews on the Mountains of Haphton, and from other Nations, to go to lay Siege to Jerusalem A great Part therefore of the Jews had Faith in; him, calling, him their Messiah. As soon as the King of Persia heard of this Matter, he commanded him to be brought before him. The King asked him: “Are thou the King of the Jews?” He answered and said, “I am,” The King then called to his Guards, and commanded him immediately to be apprehended, and led away to prison in the City of Dabastan. Three Days after this, as the King was sitting together with his Princes and Chief Minitiers, deliberating about the Jew Rebellion, behold David, having made his Escape from prison and approached and stood before him. The King looked at him and enquired, “Who brought thee hither?” He answered: “My own wisdom, and my own Subtilty because I fear neither thee nor any of thy Servants.” At which the King cried out: “Seize him!” But his servants said: “We see him not, but only hear the sound of his voice.”

Alroy then crosses the river on his handkerchief, and the King’s servants are unable to catch him in their boats. The King threatened to kill all the Jews in his kingdom. The frightened Jewish community threatened Alroy with a total exclusion from the Jewish community (“HEREM”). “In the end, David Alroy was killed in his bed while sleeping.

The story has legendary elements (seeing and not being seen, walking on water) absent in the description of Alroy’s contemporary, Al-Samawʾal ibn Yaḥyā al-Maghribi, who converted to Islam. To me, comparing the stories is less important than the passage describing the Baghdad Jews’ yearning for redemption:

“In this letter [a letter that two men forged in the name of David Alroy], they announce to the Jews of Baghdad the coming of the redemption they have been waiting for generations, in which they determine the night when they will all fly to Jerusalem, the holy city. Although the Jews of Baghdad were proud of their wisdom and strength of mind, they nevertheless tended to believe in this thing. Their wives brought all their possessions and jewelry to these two men so that they could divide all the property as they saw fit. In this way, the Jews wasted all their possessions. They wore green clothes and gathered that night on the rooftops of the houses, eagerly awaiting the moment when they would fly on the angels’ wings straight to Jerusalem. The women raised their voices in tears because they feared that they themselves would fly first before their children or the babies they were breastfeeding, and then these babies would suffer hunger.”

It is pretty clear that the Crusades and the instability in Palestine and nearby countries resonated strongly with some Eastern Jews, who saw them as precursors of redemption. The fantastic picture of the preparations for the flight and the heartbreak of the morning after also appear in other sources. Was all this commotion the talk of the day in Diyarbakir? This time not in distant Cordoba but in neighboring Amadiya,? We don’t know; even if it did, it must have been a minor event in al-Jazari’s world.

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A Goblet which arbitrates during drinking parties

Introduction

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.

 

Alcohol?

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?

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The monkey’s candle clock and Falcons

Introduction

The monkey’s candle clock is very similar to the scribe candle clock and does not justify a post. However, the clock includes a Falcon. It made me go back and see what animals reside in Al-Jazari’s book. There are quite a few: an elephant, a lion, and a monkey. You can check how knowledgeable you are in the book if you know where the lion is hiding? (Unfortunately, there are no prizes for correct answers). There are some unidentified birds, a fish with no name, an ox or a donkey, al-Jazari gave no details, but used دابّة – daba which means an animal as well as two cows. On the more exotic side, there are five dragons (!) six peacocks (!!), and the champions of appearances in the book, to my great surprise, are seven Falcons. We have another perspective on Falcons and their special place in the Artuqid court from Usama ibn Munqidh(أسامةبنمنقذ), a medieval poet, writer, knight, and diplomat. I read his book “The Book of Contemplation” (in Hebrew, many thanks to Dr. Ella Almagor for her beautiful translation). There are numerous hunting stories, including falcons, at the court of the Emir Arslan, the father of Nur al-Din Muhammad, who hired al-Jazari. This will be the focus of this post.

Monkey’s Candle Clock Topkapi Manuscript, 1206

How does it work?

Al-Jazari wrote himself:

“The [following] are made as described previously: the candle-holder, the sheath, and the falcon; the two pulleys and the weight in the center of the interior of the sheath; the channel which covers the ball’s channel, inside which is the ball’s channel; the balls.”

Donald Hill, the book translator, and annotator, devoted to this chapter only a few lines, without a drawing, and wrote that the mechanism is the same as the scribe candle clock except for the vertical movement and not circular.  Still, I am briefly repeating the technical explanation, which as always, will be colored in blue, so anyone who is not interested in pulleys or balancing weight can skip those bits. The drawing below is by the book translator and annotator, Donald R. Hill [of the scribe candle clock] modified by me:

A drawing of the mechanism by Donald Hill with my modifications

The candle is placed on a holder inside a brass sheath, and only the wick protrudes through a hole in the cap. A long rod is soldered to the bottom of the holder. The rod runs through the main weight so that the weight is free to move up and down. Two strings are connected to the bottom of the rod and through two pulleys to the main weight. The latter is relatively heavy, slightly more than one kilogram. At nightfall, the wick is lit, at that time, the candle is in full size, the rod reaches its lowest point, and the main weight reaches its highest position. As the candle is consumed, the main weight will descend exerting force, through the pulleys, on the holder upward, and the holder and rod will go up at a constant rate, depending on the rate of the combustion.

To the bottom of the weight, another string is attached, through a pulley,  connected to the bottom of the rod on which the monkey sits. As the candle is consumed, the monkey will rise and point at the tick marks. There are 218 tick marks, and each represents 4 minutes and in total 14.5 hours Diyarbakir in the middle of the winter. The holder pulls the ball’s channel up, and every hour the highest ball in the channel has risen until it is level with the hole in the back of the falcon’s head, at which point it rolls out and falls from the falcon beak.

 

Usama ibn Munqidh

“The Book of Contemplation (كتابالاعتار, literally a  Book of learning by example) is an autobiographical book written by Usama ibn Munqidh, an Arab Syrian scholar and soldier of the 12th century, a son of the Munqidh, a noble Bedouin family that controlled the fortress in Shaizar in northern Syria.

Usama was a worrier and a hunter, but also a poet, a passionate book collector, and a diplomat with charm. He was born in 1095 in Shaizar, where he was educated and lived until 1131. When the men of the Shaizar did not fight the Crusaders or other opponents, they were hunting. Syria, in the 12th century, was heaven for hunters. I thought of rabbits, wild boars, and water birds, but to my surprise, there were also bears, lions, and tigers. The use of falcons and hawks was widespread. In 1162, when he fought alongside Nur ad-Din with the Crusaders of Antioch, he met Arslan, The Artuqid Emir. Upon the end of the battle, Arslan invited him to join him in the city of Hasankeyf, the home of the Artuqids, before they took over Diyarbakir. In the next decade, up to 1174, he spent hunting and writing in the Artuqid courtyard. The fourth section of his book is dedicated to hunting stories, and I’ll tell a little about what I learned about hunting with falcons and other birds of prey.

On Falcons and Falconry

Falconry is the art of using Falcons or the other birds of prey to hunt. Evidence suggests that falconry may have begun in Mesopotamia, with the earliest accounts dating to approximately 2,000 BC. Hunting with Falcons and hunting, in general, were a popular pastime in the period of the Umayyad and Abbasid Caliphates and were beloved also in the Artuqid Palace. Usama opens the hunting stories like this:

“I have in the above given those accounts of warfare and those experiences I had in battles, fights, and adventures which I could remember and which time with its rolling years did not make me forget. For my life has been prolonged, and I have for some time now been living in isolation and seclusion. Besides, oblivion is a heritage the antiquity of which goes back to our father, Adam (Peace be upon him!)  I shall now devote a chapter to what I have witnessed and partaken of in the field of hunting, be it the chase or falconry. Some of these experiences I had in Shaizar when I was still in the early part of life…and still others I had in Diyar-Bakr with al-Amir Fakhr al-Din Qara-Arslan ibn-Dawud  ibn-Urtuq (may Allah’s mercy rest upon his soul!).”

The great love for hunting is manifested through the story of his father, who was the ruler of Shaizar and gave up his throne:

“As for my hunting experiences in Shaizar, they were in the company of my father (may Allah’s mercy rest upon his soul!) Who was extremely fond of the chase, always talking about it and about collecting birds of prey, considering no amount of expense too great for the satisfaction of his curiosity in this sport…To him, the chase was in accordance with the following traditional saying: “Air ye your hearts so that they can better retain the word of Allah!” In fact, I never saw anything like his hunting and his ability to organize parties for it.”

An Arab-Syrian Gentleman and Warrior in the Period of the Crusades: Memoirs of Usama Ibn-Munqidh – Philip K. Hitti, 1929

The book is not a guide for the Falconer, but the stories contain a lot of practical information, for example, how did they hunt the falcons?

“All that was necessary was to have a stone house built to the height of a man. It would then be covered with branches concealed under hay and grass, with an opening. The trapper would then secure a pigeon, perch it on a stick, binding its two legs tightly to the stick, and display the pigeon from an opening, as a lure. As he moves the stick up and down, the pigeon flutters its wings. Seeing it, the falcon turns down and pounces on it to seize it. As soon as the hunter feels the falcon, he pulls the stick back to the opening, stretches out his hand, and seizes the two legs of the falcon.”

There are plenty of stories, but the story of al-Yahshur, an exceptional falcon demonstrates the unique relationship between the Muslim nobility and the predatory birds used for hunting:

Between Osama’s father and the sons of Rubal, the ruler of Armenia was a relation of friendship, and every year they would send him several falcons. One year a young broad like a saker [A falcon native of Southern Europe and Asia] arrived, but it could not keep up with the other falcons in flight, yet the falconer Ghana said, “Among all the falcons there is none like this young one, It will let no game escape it”. We could not at first believe him, but for the next thirteen years, al-Yahshur was the king of the hunting birds in Shaizar. The special relationship between his father and al-Yahshur can be seen here:

“When we entered the house, my father would say, “Fetch me a bowl of water.” They would fetch him one, and he would offer it to the falcon [al-Yahshur] while it was still on his wrist (may Allah’s mercy rest upon his soul!). The falcon would drink it. In case it wanted a bath, it would shake its beak in the water. My father would then order that a big basin full of water be brought and would offer it to the falcon… when it would get out of the water. My father would put it on a large wooden perch, especially made for it and would bring near it a brazier of live coal; and after it was combed and rubbed with oil” until it was dry, a folded piece of fur would be placed by it. The falcon would go down to it and sleep. It would remain among us sleeping on the fur until late in the night, at which time my father would want to retire into the harem’s apartment. He would then say to one of us, “Carry the falcon.” And the falcon would be carried as it lay sleeping on the fur until it was placed near the bed of my father (may Allah’s mercy rest upon his soul!).”

My love, M. says that I cannot tell about hunting with birds of prey without refereeing my readers to the movie about Aisholpan:

A young Mongolian girl who hunts with a golden eagle. This is, before anything else, a story about the power of a young woman who has managed to change Mongolians traditions. However, this is also a story about the deep connection between the hunter and his hunting bird. This is why there is no surprise in the number of falcons that penetrated al-Jazari’s machines.

A miniature of a falconer, North France, 1180.

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What is so beautiful about this door? (Cast brass door for the Artuqid Palace in Diyarbakir)

Introduction

The sixth and final category in the book contains five dissimilar designs. The first and most grand of all is the Artuqids Palace door in Diyarbakir, Eastern Anatolia. Al-Jazari opens this chapter with some enthusiastic message very unusual for him:

“It is the masterpiece; to view it saddles are strapped on. Truly it is the pearl, the orphan, a priceless possession.”

This passionate text surprised me because this door, engineering speaking, is quite simple and doesn’t contain the inventions and surprises included in most of al-Jazari works. The beauty is not in engineering, but in the art and the craft. Donald Hill, translator, and interpreter of the book, Engineer by heart, was interested mainly in the casting technology: “Of particular importance, also, is the first unequivocal description of metal casting in closed mould-boxes with green sand, a method not used in the West until the end of the fifteenth century.” Casting is a manufacturing process in which a liquid metal (al-Jazari used copper, brass, and bronze) is poured into a mold with the desired shape. “Green” sand is used even today. The name is a bit confusing as the sand is not green color at all. Instead, the sand is called “green” because it is “wet” sand, which contains water and organic bonding compounds much like we say “green wood” in carpentry.

I have two very different questions:

  • Sorry, what is so beautiful about this door? Or at least why al-Jazari admired his work?
  • How is it possible that military considerations are not part of the design? What does it say about al-Jazari as an engineer?

Description of the door and its beauty

It is a door with two leaves which rise to the height of about four and a half meters (originally 18 spans ( شِبْر) ) and the width of each leave is a meter and a half.

The Palace door, Topkapi Manuscript, 1206

The Palace door, Topkapi Manuscript, 1206

In the center of each leave, there is a complex geometric pattern that includes Hexagram (Star of David) and Octagram. It is interesting to note that both these shapes belong to the family of Magic stars. A magic star is a star polygon in which numbers are placed at each of the n vertices and n intersections, such that the four numbers on each line sum to the same magic constant: M=4n+2. The solutions I know to magic stars are only from the 20th century, but the use of the two was very common in the Muslim world. Is it possible that al-Jazari sensed mathematical beauty without knowing the math?

Since it is a relatively complicated pattern, I colored the drawing to see Magic Stars:

Islamic art makes frequent use of geometric patterns which were developed over the centuries. There is  “artistic unity” across time and place. I bring three pictures of three doors with different geographical, cultural and historical background, both Shi’ite and Sunni Islam

The left door is a Turkish door from the14th-century. The middle door is a Grand Palace in Fez in Morocco from the 13th-century. The wooden door from Iran on the right is not dated.

The Islamic aesthetic shift toward complex geometric structures is attributed to the prohibition in the Qur’an of figurative images to avoid becoming objects of worship. Geometric structures are abstract, emphasized symmetries, and suggested infinity and therefore reminding Muslims the idea of the infinite nature of Allah. This explanation does not satisfy me since the second commandment :

” Thou shalt not make unto thee any graven image or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth. Thou shalt not bow down thyself to them, nor serve them”

Did not yield a similar tradition in Jewish art. I don’t see anything that would justify the special enthusiasm from the geometric patterns of al-Jazari. However, if any of my readers find some special beauty or a hidden message, please comment as I would love to learn.

The pattern was bounded by brass plates a which carried Kufic((كوفي ) inscriptions and leaf motif decorations. This reads “the dominion is God’s, the One, the Conqueror”

Kufic is the oldest calligraphic form of the various Arabic scripts. Kufic developed around the end of the 7th century in Kufa, Iraq, from which it takes its name, and other centers. Kufic was prevalent in manuscripts from the 7th to 10th centuries. In the late 12th century, when the door was made, it was less used, and I do not know if this choice has a special meaning?

The calligraphy is surrounded by  bronze plates which were decorated with red copper leaves:

The process is relatively complex; firstly, he casted bronze panels. Using a scalpel, he carved the leaf template and poured melted red copper.

In the drawing, there are no brass domes, but in the text, there is a detailed explanation and diagram of a dome. I took the liberty to add this to the original drawing by al-Jazari:

I did not cover every detail, but I cannot ignore the door’s knockers from cast brass in the shape of two connected serpents, their heads facing each other. Their mouths are open as if they wished to devour the lion between them.   The door did not survive (I am convinced it was built, and not just designed, because of the richness and the details in the text). It is interesting to note that very similar Bronze door-knockers from the Great Mosque in Cizre are now in the Museum of Turkish and Islamic Arts in Istanbul. To my surprise, pretty similar versions have found their way to Copenhagen and Berlin museums.

We will never know what caused al-Jazari to be that happy with this door. Maybe he enjoyed his geometric patterns and thought particularly beautiful, Maybe He enjoyed his success in the complex casting or his work with various metals, brass, copper, and silver, maybe he was happy the amount and richness of the details and possibly it was a combination of all.

 

Military engineers and engineering history

Engineering has existed since ancient times, the invention of a pulley, the construction of the Egyptian pyramids or the copper production process are all “Engineering” according to all modern definitions but only in the 14th century was the first use of the term engine’er. The origin of the word is from Latin words “in generare” meaning “to create” but relating to the designing or creating engines of war like the catapult or assault towers. For many years all the engineers were military engineers. Archimedes, a gifted mathematician and scientist had a major role in the Second Punic War. He improved the power and accuracy of the Catapult, He designed a giant claw to destroy Roman ships, and the peak of his inventions was burning the Roman fleet using mirrors.  Leonardo da Vinci engineering career included military chapters as evident from his letter to Ludovico Sforza, ruler of Milan. He wrote:

“I have plans for very light, strong and easily portable bridges with which to pursue and, on some occasions, flee the enemy.. Also, if one cannot, when besieging a terrain, proceed by bombardment either because of the height of the glacis or the strength of its situation and location, I have methods for destroying every fortress.”

The Faculty of engineering at the Technion is still called “civil engineering,” to be separated from military engineering, although the former has become almost a non-issue in the modern world of engineering.

It is somewhat surprising that there is no military engineering chapter al-Jazari’s work and even when he builds the door for the Palace, no considerations of strength or defense capability are mentioned, not even a single word. Two possible explanations:

  1. The principality in Diyarbakir was so peaceful that there was no need for a military engineer.
  2. The expectations from the Court engineer in Diyarbakir were different.

 

A change in Diyarbakir and al-Jazari as an “engineering magician.”

The dynasty was founded by Artuk Bey, a general under the Seljuq emir of Damascus. In 1086 he was appointed the governor of Jerusalem, a surprising twist to a story about a Muslim dynasty which ruled in Diyarbakir Anatolia. We need to remember that the Middle East map in the 11th and 12th centuries is very different from the map we know today. After Artuk death in 1091 his sons, Sökmen and Ilghazi were expelled from Jerusalem by the Fatimid vizier and set themselves up in Diyarbakır and Mardin in Anatolia.

This door was installed at the Artuqid Palace in Diyarbakir where al-Jazari was the court engineer. The Palace was built within the walls of Diyarbakir during the reign of Salih Nasreddin Mahmud (1200-1222) Artuqid king who employed al-Jazari like his father and brother before him. The Palace was excavated in the 1960s, but most of it is still buried under the mound, and I have a fantasy that the site will be excavated a second time and we will find some of the remains of al-Jazari’s work. In the 12th century, there were a few battles with the Crusaders, with Georgia and clashes of within the Muslims. I don’t think a peaceful period is the explanation of the absence of the military aspect in al-Jazari’s work.

The Artuqids are a Turkmen dynasty which started as a warrior tribe, and its original power was military. In the 12th century, they were settling in the old cities of Amida (the previous name Diyarbakir ) and Mardin. These are ancient cities with urban culture since the Assyrians. The population is diverse and includes veteran Christian and newcomer Turkmen population as well as other migrants from Iran and other places that continued through the 13th century. Beyond the monumental Al- Jazari book, there was probably a workshop for copying and illustrating manuscripts. Rachel Ward identified two other illuminated manuscripts that were produced there. There were new architectural designs, Sharon Talmor as part of her graduate work at the University of Tel Aviv found three which mark a new era in Islamic architecture. As a part of the assimilation of a warrior tribe into the urban setting, there was probably a need for a change, and there was a thirst for cultural and artistic activities. I’d love to hear other suggestions too, but this is a possible explanation for the absence of military engineering.

So the circle closes. The question of the beauty of the door is connected to the role of al-Jazari. As we step into the book, I think we will be more convinced of his role as  “a magician of engineering”  the man who harness science and technology to create and beauty and astonishment.

 

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Automaton of a slave pouring water and the Artuqid court

Introduction

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.

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The Arbiter for a drinking session

Introduction

This is a drinking game for the effervescent parties in Diyarbakır Palace as we met in The automaton who drinks the king’s leaving and A boat placed on a pool during a drinking party (in Hebrew).

The Arbiter is a complicated automaton (a self-operating machine) which includes: A slave (جارِية) pouring wine to a goblet in the lower level. Above her, on a balcony, there are four slave girls who play music on a flute, tambourine and a lute. Above them, there is a half-naked male dancer in a niche, and on top of the dome, there is a horse rider carrying a lance. During the party, the musicians play their instruments, the dancer dances (I swear!) and the horse and the rider rotate slowly. When commotion stops the slave girl tilt the bottle and pours wine to the goblet. A servant (a living person) takes the goblet and serve it to the participant the spear points to his direction. The process repeats itself twenty times, almost seven hours in total. At that time the black doors behind the dancer open and a man emerges out of the door, his hands are in the air, signaling that celebration is over and there is no more wine. Al-Jazari calms the worried reader, saying that the head of the assembly can choose to refill the reservoir. The wild parties in Diyarbakir can raise a lot of questions about the crazy amounts of wine, the half-naked dancer, and more. Maybe I will write about all this in the future. I want to focus on clothes, did observer of the automaton in the 12th century knew she was a slave by her dress?  What can we learn from the text and the illustrations about clothing in the Artuqid palace?

The Arbiter for a drinking session. Topkapi manuscript, 1206.

How does it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in floats, Tipping buckets or camshaft can skip those bits. The illustration below is my modification of the drawing from the book; it will help us to follow the mechanism:

Drawing of the mechanism

In the beginning, a servant lifts the dome (1) and fill the reservoir (2) with filtered wine.  At the bottom of the reservoir, there is a thin pipe, so wine is dripping to the tipping bucket(3). I wrote about tipping buckets before, for example in the fountain of the two tipping buckets (in Hebrew). In the front view, you can see the tipping bucket in action. After twenty minutes the bucket is full of wine, and it becomes overbalanced, and tips down, emptying itself on the scoop wheel (4) which turns the adjacent teeth wheel (5) which turns the 900 teeth wheel(6) which is connected to the rider axle(more clearly seen from the side). This makes the rider rotates, and the “lucky” participant that the spear is pointing in his direction will get to drink the goblet. I used quotation for “lucky” because the goblet contains a liter of wine, more than an entire bottle! I don’t know what the alcohol content in the 12th century was, but it seems like a sure way to get drunk with a severe hangover. I do not want to think about someone who was lucky enough to win two goblets during the seven hours of the party.  The wine from the scoop wheel is collected and falls on the second scoop wheel(7). The rotating wheel rotates the axle and the pegs(8)connected to it, hitting the levers connected to the musician’s arms. This causes the up and down movement, simulating the drummer bit and the playing of the lute. The rods, an early version of camshaft transform the circular motion into linear motion were the rods pattern creates different drumming bit and lute music. The wine flow from the 2nd scoop wheel to the air tank, pushing air in a narrow pipe with a whistle at the end(9). This produces the sound of the flute player. Finally, the wine goes down in a hidden tube (10) through the slave body and fills the bottle. The latter is on an axle, and the weight will cause it to tilt and fill the goblet. For clarity, I skipped two mechanisms. Readers who love to ponder on this kind of gadgets can try to decipher the remaining components and questions will be, as always, appreciated.

Fashion and clothing in the “Book of Knowledge of Ingenious Mechanical Devices.”

The choices of clothing by Muslims reflect their religious and cultural world. We call the veil worn by some Muslim women to cover their hair- hijab (Arabic: حجاب). In the Qur’an and other classical Arabic texts, the term was used to denote a partition, a curtain and it is a generic term for modest attire. During the Hajj (حَجّ), the pilgrimage to Mecca, one of the five pillars of Islam, the men wear a white outfit that was not touched by a needle or thread (how is that even possible?).  What (if anything) can we learn about life in the 12th century in Diyarbakır by looking at the illustration and the few direct references of al-Jazari to clothing details?

Five slaves from the “Book of Knowledge of Ingenious Mechanical Devices” Topkapi manuscript,1206

In the top left illustration, we can see a young black slave (غلام) truncates the candle wick from The candle clock of the swordsman (Hebrew). No explicit description of him in the book but his attire is the simplest, in comparison to all the other slaves and includes a short red dress with stripes on the sleeves. The sleeves’ stripes appear in almost every dress of slaves or free men. I don’t know if this was the fashion in Diyarbakır or the stripes had a meaning or use? If a knowledgeable reader can enlight me, I would love to learn.

The slave girl pouring wine at the center is from the automaton in the present post. She wears a blue dress or gown with decorations that cover her from neck to ankles. She also has two brown stripes on her sleeves. The garment doesn’t look “cheap” or “service uniform” Her black hair can be seen under the cover. Although her dress could have been worn by devout Muslim today her head cover is not acceptable by contemporary moderate standards (hijab) and certainly not by more religious Muslims demanding a niqāb or chador.

We met the slave washing the king’s hands here (in Hebrew). The illustration, in this case, is large and rich with details. The blue dress is very similar, if not identical, to dress of the slave girl. It is particularly interesting. Muslim men are forbidden(حَرَام‎ ḥarām) to wear silk clothes or gold jewelry. This is not from the Quran but a later story told by Ali Ibn Abi Talib, Muhammad cousin and the fourth Caliph accepted by both Sunni and Shia. The restriction is very specific but interpreted as an echo of the biblical verse:

“The woman shall not wear that which pertaineth unto a man, neither shall a man put on a woman’s garment: for all that do so are an abomination unto the Lord thy God.”

(Deuteronomy 22:5 King James Version)

It is possible that his red jacket without sleeves is enough to distinguish between them? He is also wearing a small red hat quite similar to the fez (more correctly ṭarbūsh). It is interesting to note because the ṭarbūsh is usually attributed to the period of Sultan Mahmud II (1808-1839) when it was introduced as part of the Ottoman Empire judges and spread to clerical circles and the educated elite.

The next slave, to the left and below, is from the automaton of a standing slave holding a Fish and A Goblet. In this case, al-Jazari himself provides a relatively detailed description of the dress:

” He is a standing slave, ten years old in appearance, dressed in a short jacket (farajiya) with a robe(qaba) underneath it, and a cap (qalansuwa) on his head.”

The qaba (قابا, I hope I spelled right?) is a type of a robe with sleeves, at mid-calf –between the knee and ankle that has a diagonal fastening of one side over the other. The “Encyclopedia of Islamic Civilization” claimes that in Abbasid times qaba belonged to the military? According to the illustrations in the book, the qaba was widely used among slaves and free men. The hat (qalansuwa  = قلنسوة‎) is written like the Arabic city in the center of Israel; I don’t know if this is the origin of the city name. This hat was quite popular, and Harun al-Rashid was wearing this hat in his nocturnal wanderings through Baghdad in disguise. Unlike the qaba which repeats itself in many illustrations, there is quite a selection of headdress. For example, the slave girl who emerges from a cupboard holding a glass of wine is covered with a colorful scarf with a picturesque ribbon. Quite similar to today hijab. She is also wearing loose red trousers under the qaba. This combination can be found both in the book and outside.

Eight “free” people (in the sense of not slaves) from the “Book of Knowledge of Ingenious Mechanical Devices” Topkapi manuscript,1206.

The top left illustration is the scribe from the elephant water clock. There are three scribes in the book, all three wear green qabas with brown stripes on the sleeves and wear pale blue turbans. I couldn’t find any evidence of “professional clothing” of scribes. You should also note that the scribe has a beard. Allowing the beard to grow (لحية) and trimming the mustache is mandatory in Sunni Islam and is considered to be Fitrah (فطرة‎) or the state of purity and innocence we are all born with including the natural tendency to distinguish between good and evil and to believe in the existence of Allah. As none of the slaves are bearded, they probably weren’t Muslims.

The two Sheikhs are part of the automaton in Category II dedicated to vessels and figures suitable for drink sessions.  Al-Jazari did not write anything about the Sheikhs, but Sheikh (( شيخ is a title given to the leader of the Bedouin or Arab tribes. The meaning of the name in Arabic is old, although the Sheikh is not necessarily old. They are also dressed in qaba and turbans. I don’t see in the illustration a difference between the of Sheik’s qaba and the slaves’  qaba. It is quite possible that there were large differences in the quality of the cloth or decoration which are not captured in the illustrations. However, the turban characterizes only the free people. Before anything else, the turban was practical in protecting the eyes from the sand and providing the face protection from the sun.  On top of this, the turban (عمامة, pronounced amama) was part of Muslim’s traditional attire and their identity. The turbans were a source of pride and a symbol of religious affiliation. Taking a man’s turban was considered a humiliating act, touching someone’s turban was perceived as an insult. It explains well why none of the slaves wear a turban.

The last picture below is from the musical boat(Hebrew). This is the King and his boon companion ( نديم =Nadim) I wrote about it here (Hebrew). Everyone is wearing a qaba, including the King himself. His blood-red qaba has gold trim. On top of the decorations, everybody has, he has additional decorations of the collar, the cufflinks and the fringes of the qaba as well as a golden belt. Red is not necessarily Royal, another member of the party is wearing red, though with fewer decorations.

I’m pretty sure al-Jazari was very surprised from this post, and it didn’t occur to him that the illustrations he prepared to improve the understanding of his machines, and are truly groundbreaking, would become a fashion guide for 12th century Diyarbakir. However eight hundred and twelve years later this is the only window that would allow me to peep into the  Palace in Diyarbakır. At least for me, this was an interesting journey.

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The Magic Pitcher, a Walnut and the Art of Motorcycle Maintenance

Introduction

Al-Jazari describes a handsome pitcher of beautiful workmanship.  The slave brings it at the end of the meal and pours over a diner’s hands moderately warm water. To the surprised spectators, he serves a second,  miserable diner with water, too hot for bathing and too cold water for a third. Finally, he tilts the pitcher, and no water comes out. To the delight of the company, he continued his round and selects the “winners” who would receive proper bathing and the other who would get the party laugh. We are used getting cold or hot water by will, in the twelve century this was a technology miracle. To the best of my knowledge, this is the earliest Thermos, an insulating storage vessel for cold\hot drinks.

Water Pitcher, variable temperature, 1206 Topkapi manuscript.

How does it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in heat transfer or patents to insert and take out water can skip those bits. Al-Jazari took a brass pitcher and removed the bottom and welded two parallel plates with a finger wide air gap in-between them.  Al-Jazari wrote that he tried to use a single brass plate as a spacer, but the cold water was heated, and the hot water got cold as expected. The copper is an excellent heat conductor, while the air trapped between the plates is an excellent heat insulator. Donald R. Hill,  the book translator, wrote:

“Although al-Jazari describes these devices at considerable length, the designs show little advance on those described by the Banu Musa [you can read more here] Indeed the latter are in several ways more sophisticated.”

However, to my knowledge, this is the first use of double walls and air insulation, and like a lot of al-Jazari work was obtained by trial and error. The drawings of al-Jazari are usually exceptional, but in this case, he chose a section that makes it more difficult, at least for me, to understand. I attach a contemporary drawing made by Donald R. Hill, The book translator, and annotator, showing two cross section. I added captions.

A drawing made by Donald R. Hill, The book translator, and annotator, showing two cross section of the pitcher.

On the right side, we look at the pitcher, perpendicular to both the copper plates dividing it into two tanks; one for hot water and one for cold water. The distance between the plates was enlarged for clarity. In reality, it was “a finger” about 2 inches. In the upper third of the pitcher, two funnels were installed, leading the hot water to its tank and the cold water to its half of the pitcher. To fill the pitcher, al-Jazari used a deflector on an axle. You can see it in both sections. The plate had a heavier side, towards the cold water so that one would fill the cold water first. When the cold water tank was full, the float pushed the deflector plate which tilts toward the hot water tank and enables us to fill the other half. A second buoy (al-Jazari used a walnut) with a gauge marked that this tank was also full. The Pitcher had a hollow handle with two holes for air entry. The holes were connected to two pipes, one leading to the half pitcher with cold water and the other to the half of the hot water.  When the slave leaves the two holes open, air enters to both sides of the pitcher, and mixed water, in a comfortable temperature, comes out of the nozzle. When the slave covers one of the holes, water comes out only from the side of the pitcher that has an air inlet, hot or cold depending on the hole he sealed. If the slave sealed both holes, no water would come out at all.

spirit of silliness

Al –Jazari  wrote:

“It is a pitcher of handsome workmanship with a handle and a spout. The slave brings it on a tray at the end of the meal and places it in front of the diner [al-makhdum -lit. the one being served]. He lifts the pitcher from the tray and pours over the diner’s hands moderately warm water, with which he completes his ritual ablutions (wudu) or the washing of his hands. Then on the hands of the person whom he is putting to the test he pours hot water unbearable to the touch, so he cannot wash his hands. Then on the hands of the person whom he is putting to the test he pours very cold water, unbearable to the touch. Then he tilts the pitcher over [the hands of] the person whom he is putting to the test and nothing comes out of the pitcher. He pours out [warm water] to whomsoever he wishes in the company, and refuses it to whomsoever he wishes.”

This description fits better the court jester than a slave servant. Assuming he survived the night, it is also a testimony about a folly in the court in Diyarbakır. Court jester was a medieval profession responsible for fun and entertainment in the courts. Most of us know the Western version with colorful clown clothes, jester hat and a wand. But there are also court jesters in the Islamist courts. A Persian version called the DALQAK is somewhat similar, In the book  “Fools Are Everywhere: The Court Jester Around the World” there is a list of the jesters in the Abbasid Caliphate. The most famous one Abū Nuwās who was a poet and a jester in the court of Harun al-Rashid and appears several times in The Book of “One Thousand and One Nights.”

Jesters, musicians, and dancers in a Turkish miniature, Topkapi Palace

The role of the Court fool in medieval times was to speak honestly, sometimes even mocking the King or his noblemen without suffering the consequences. For example in the Book “Of Fools at Court “ by Clemens Amelunxen when a powerful nobleman complained that a fool was walking on his right, the jester hopped over to the left and answered in sarcasm: “well, I don’t mind a fool walking on my right!”. It is possible that the pitcher stunt was part of the leeway that was possible for the court fool. Either way, this is a little surprising glimpse to the court culture of the Artuqid.

Zen and the Art of Motorcycle Maintenance

I read the book “Zen and the Art of Motorcycle Maintenance”  by Robert m. Pirsig, few years before I had my own BSA Motorcycle that needed everything I know about bike maintenance and challenged the mechanics in Chlenov street garage when I was not sufficient. I found this book in a used Bookstore and even if I did not immerse in the roots of the debate between Sophists and Socrates, I was deeply moved by the book and three or four stories are part of me ever since.

Robert m. Pirsig

The book is the story of a journey of Pirsig and his son on a motorcycle across the United States. This is partially autobiographical, weaving the journey in the United States back roads with a complicated internal search (he underwent a mental breakdown and hospitalization) and deep philosophical discussions.

Pirsig and his son ride with his close friends John and Sylvia. They have an expensive BMW motorcycle and John, like most of us, wants to enjoy driving it without getting into maintenance and technological problems.  The handlebars of John’s BMA started slipping, and Pirsig is offering to shim them with a can of beer. He writes:

“I thought this was pretty clever myself. Save him a trip to God knows where to get shim stock. Save him time. Save him money. But to my surprise, he didn’t see the cleverness of this at all…. As far as I know, those handlebars are still loose. And I believe now that he was actually offended at the time. I had had the nerve to propose repair of his new eighteen-hundred dollar BMW, the pride of a half-century of German mechanical finesse, with a piece of old beer can!….What emerged in vague form at first and then in sharper outline was the explanation that…I was going at it in terms of underlying form. He was going at it in terms of immediate appearance. I was seeing what the shim meant. He was seeing what the shim was… Who likes to think of a beautiful precision machine fixed with an old hunk of junk?”

Should you ask how this story is connected to al-Jazari?  Without any discussions or explanations, he used a Walnut as a buoy. To me, this is identical to using a beer can as a shim, i.e., looking at things in terms of the underlying form. I would like to finish in a quote from Pirsig on the essence and form. If I replaced steel with copper, Al-Jazari (in my opinion) would agree with every word:

” I’ve noticed that people who have never worked with steel have trouble seeing this—that the motorcycle is primarily a mental phenomenon. They associate metal with given shapes—pipes, rods, girders, tools, parts—all of them fixed and inviolable, and think of it as primarily physical. But a person who does machining or foundry work or forger work or welding sees “steel” as having no shape at all. Steel can be any shape you want if you are skilled enough, and any shape but the one you want if you are not.”

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The Elephant Clock – Multiculturalism or a Circus?

Introduction

The elephant clock is by far the most popular of all al-Jazari’s works. There are a few modern reconstructions of it: some in different exhibitions and museums, but also one in the Dubai Mall. The clock has a variety of animations in 2D and in 3D, and it even has its own Wikipedia page. Due to the complexity of the mechanism, I divided this post into two; in the first part, I will explain what the viewer sees and try to explore the sources of the magic. The second part will be more engineering-oriented, and I will explain how the mechanisms work in the backstage, and what is so unique about this clock.

The Elephant clock, manuscript from 1315, Syria

What does the viewer see?

An elephant,  approximately one meter and twenty centimeters long, who is carrying on its back a canopy with four pillars and a castle. On top of the castle’s dome, is a bird. Inside the elephant, is a hidden water reservoir and a sinking float (a float with a hole that sinks slowly) during half an hour. More details in the next post. In the canopy sits a scribe holding a pen pointing at a semi-circle with tick marks. During this half hour, the scribe rotates and his pen indicates the minutes that have passed. At the end of every half hour, the scribe returns to its original position. At the same time, there will be quite an impressive show. Between the elephant’s shoulders, rides a mahout (the elephant keeper and driver). In his right hand, is an ax and a mallet in his left. Every half hour the mahout strikes the copper elephant, first, with the ax and then with the mallet. In the castle balcony sits a man. His hands are on the heads of two falcons which he keeps them from opening their beaks. Once every half hour, he raises one of his hand, and the corresponding falcon shoots out a ball. The ball falls into the dragon’s maw, making the dragon swing on its axis and then lay the ball on the cymbal in a jar. During this time, the bird on the dome is also spinning. Above the head of the falconer is a semi-circle with fifteen black holes. Every full hour one hole turns so that the sum of white indicates the number of hours passed since sunrise.

You can see a short video demonstrating the elephant clock and explaining the mechanism:

 A fuller explanation will also come in the next post.

Why an elephant?

The Elephant water clock entry in Wikipedia reads:

“The elephant represents the Indian and African cultures, the two dragons represents ancient Chinese culture, the phoenix represents Persian culture, the water work represents ancient Greek culture, and the turban represents Islamic culture signifying the multicultural mentality of the intellectual al-Jazari. “

The quote certainly is not by al-Jazari, but whoever wrote it explained the wealth of the clock. Nonetheless, it made me think. I am afraid that the whole concept of multiculturalism is completely foreign to the 12th century and al-Jazari. What is a possible explanation for the elephant?

The Middle Ages and strange elephants

The trade routes in the middle ages were spread over Europe, the Middle East, India, China, and  Africa. On the east coast of Africa, they traded ivory, gold, ebony, and slaves. China exported silk and porcelain, India spices and drugs. Rumors about elephants, giraffes, and other exotic animals reached Europe but the artists who drew the manuscripts had never seen an actual elephant. They drew them based on their imagination. There is an entire site dedicated to the weird drawings of elephants. I give just two examples:

Thomas of Cantimpré, Liber de natura rerum, France 1290

A hoofed wooly elephant “Livre des simples médecines” a manuscript from the 15 century.

The original manuscript by al-Jazari was unfortunately lost, but the manuscript from Topkapi is from 1206, I wrote about it here. This is the year al-Jazari died, so it is probably a copy of the original. You can see that the elephant looks like an Asian elephant and the mahout and the canopy are located correctly. Al-Jazari’s familiarity with elephants is not necessarily surprising, although I couldn’t find any evidence for elephants in Diyarbakir. Arab rulers had menageries or collections of exotic animals. In addition to the curiosity and pleasure they provided, they demonstrated the ruler’s wealth and power as well as the impact of the sovereign from India to Africa. Offerings of rare animals were part of the diplomatic process and sometimes part of the tax system. Until the 13th century, the agreement between the Nubian Kingdom and the Muslim rulers of Egypt demanded that the Nubian people provide Egypt with three hundred and sixty slaves annually, in addition to providing some wildlife. It This was the primary source for giraffes in the Sultan of Cairo’s menagerie.

Book of the animals, Syria, 15th Century.

The use of animals as a diplomatic gesture is well documented. For example, Baybars, the Mameluke Sultan of Egypt and Syria in the 13th century gave elephants, giraffes, and zebras to the king of Spain, Emperor of Byzantium and the Mongol Khan. In the 10th century, Cordoba sent a giraffe to Tunisia and a story I particularly like about the elephant, Abul-Abbas. Harun al-Rashid,  the Abbasid caliph in Baghdad, sent an Asian elephant to Aachen, Germany to the Carolingian emperor Charlemagne. It happened in the 9th century, and surprisingly enough, there’s a Jewish angle to this story. The elephant was brought by Yitzhak the Jew. There is a historical novel “The travels of Isaac the Jew and Abu Alabas the elephant”(in Hebrew). It is interesting to note that other presents including an elaborate water clock made of brass, described in the Royal Frankish Annals were sent with the elephant. The water clock marked the 12 hours with balls of brass falling on a plate every hour, and also had twelve horsemen who appeared in turn at each hour.  Perhaps al-Jazari knew the story as part of his extensive knowledge of water clocks?

The Elephant Clock and the Circus

The diplomatic delegations and the royal gifts indicate that the elephant was a symbol of power and wisdom, but in the context of the elephant clock, I think more about the circus and exotic acts. The elephant is made of copper and is just a stage for the show, but the swinging dragons, the Mahout with his fearsome tools, the Falcons and the spinning bird form a great circus number. An exciting circus act has, in my opinion, four components, not in binding order, not always all of them, and certainly not of the same significance or importance:

  • Freshness (something new)
  • Great skills
  • A sense of danger
  • An awe-inspiring images

I looked at several iconic circus shows and Jules Léotard’s act is a good point of comparison. Léotard was a French acrobatic performer who made history as the first man ever to perform the aerial act on a trapeze. It most certainly meets the requirement for freshness. Likewise, the elephant clock is also the first of its kind; no clock ever, before or after, is similar, and everyone who watches it, even today, is amazed.

Secondly, great skills: Léotard practiced his acrobatic stunts over his parents’ pool before he revealed them in 1859 in Cirque Napoleon in Paris. Then he appeared in London before an audience that went crazy because of his aerial flips between five trapezes with only a pile of mattresses to protect him. The elephant clock also demonstrates such high proficiency and skills both to the innocent and to the skilled observer, considering the control of the timing using the sinking float, the complex movement of the three characters(the mahout, the scribe, and the man in the balcony), and the virtuoso swing of the dragons. All are innovative engineering tricks demonstrating al-Jazari’s skills in water clocks and automatons.

Regarding the sense of danger, the crowd in the circus was afraid for Léotard’s life and this element intensified the experience; however, automatons by definition lack this aspect.

Jules Léotard, a French acrobat, 19 century

Last but not least, the awe-inspiring image. Léotard, like all circus performers, could be dressed in a sports suit, but as you can see in the picture he’s wearing theatrical shorts, bracelets emphasize his wrists, and the collar of his shirt reminds us of a royal necklace. All this help to imprint his image in our mind.  The picture that al-Jazari created is a lot more than the sum of its components and is intriguing audiences till this very day.

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The Beaker Water-Clock

Introduction

Al-Jazari  himself wrote the introduction to this chapter, and It makes sense to bring his opening remarks:

“The king, Salih. Abu al-Fath. Mahmud, may God assist Islam by prolonging his life, proposed that I should make for him an instrument having no chains, balances or balls, not liable to rapid change or decay, from which could be told the passage of the hours and the divisions of the hours without inconvenience. It should be of handsome design and suitable for journeys or for settled residence. I considered the matter and made, according to his suggestion, what I shall now describe. “

What follows is the water clock of the scribe (in Arabic ورّاق). The clock design required two computational parts:

  • The clock face or dial supports solar
  • The slope of the beaker radius requires some understanding of fluid mechanics.

This post is relatively heavy in mathematics, and the “blue” parts (the technical explanation) are larger than usual. I Hope you can prevail them well.

The water clock of the beaker. Probably a dispersed manuscript from Cairo, 1354

How does it work?

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 drawing below is the Beaker water clock mechanism with my captions:

This is a copper beaker divided into two parts, upper beaker and a base are connected by an onyx with a very fine hole. The beaker is filled with water at the beginning of the day. The float is raised to its maximum height, and the weight is hanging down as far as possible. During the day the water would discharge slowly through the onyx to the base. As a result, the float would sink, and the weight would rise, causing the large pulley to rotates with the scribe and his pen. The water is sufficient for 14 hours and 30 minutes for the longest day of the year. At sunset, the water is returned to the beaker from the base, and the process repeats itself.

You can watch this short YouTube video from Technology & Science In Islam” showing the beaker clock :

iframe width=”854″ height=”480″ src=”https://www.youtube.com/embed/LNpDtxpBWes&#8221; frameborder=”0″ allow=”autoplay; encrypted-media” allowfullscreen></iframe>

Two engineering issues need further discussion:

  • The clock face and the variable length of the day.
  • How did al-Jazari find a practical solution to Bernoulli’s equation which he did not know or understood?

    The clock face and the variable length of the day

    In summer the days are long and the nights are short and vice versa in the winter. We’re moving the clock one hour forward at the beginning of the summer (“DST” – Daylight Saving Time), and at the fall we set the clock back. The Idea of the “DST” is attributed to Benjamin Franklin, and the rationale is energy saving, but it was suggested that daylight saving time improves quality of sleep, as we sleep longer during the darkness that allows deeper sleep and we know that a lack of sunlight can cause Seasonal Affective Disorder. Al-Jazari also dealt with the variable length of the day. Below is a screenshot from the YouTube clip. I added some captions.

    The clock face,  “Technology & Science In Islam” with my caption.

    The clock face is divided into eighteen bands, and each band is divided into twelve equal solar hours.  The outer band covers 3600; it is designed for ten days from June 21 (the summer solstice). The solar hour will be 300, but in Diyarbakır, there are about 14.5 hours of daytime so that the solar hour will be longer by~ 12 minutes in comparison to the constant hour. The eighteenth band(innermost) is intended for the last ten days of December. Diyarbakir has only 9.5 hours light, and therefore the band was shortened:

     9.5/14.5* 360 = 2360

    Every hour will be slightly less than 200 so the hour is only 46 minutes! 

    The concept of solar hours seems very strange in the 21st century and complicates everything. Just to think that programmers will be forced to change program timings with the calendar.

    Our notion of time rests on the celestial bodies movement. The years were counted based on the Sun or the Moon and the day, hour, minutes, and seconds were all derive from it. In fact, until 1967 the second was defined as 1/86,400 of a mean solar day. Only with the development of the Atomic clock, the definition was detached from the Earth’s rotation cycle, and the second is defined to be exactly 9,192, 631,770 cycles of a Cesium atomic clock. As weird as it may sound, atomic clocks and their ridicules precision are part of our daily life, and we cannot use Waze, or any navigation software, without them. In the world of the 12th-century solar hours made perfect sense and were more connected to nature and the movement of the celestial bodies.

    Bernoulli’s equation and the “solution” of al-Jazari

    A difficult problem in any water clock is that the water flow is not constant but depends on the water level in the tank. The following diagram illustrates the problem. For simplicity the beaker is cylindrical, and the onyx was inlarge for  clarity:

It is clear that at the beginning of the day when the beaker is full of water the water flow will be much stronger in comparison to the water flow after ten hours when the water level in the tank has dropped. How can we calculate the water flow and what can be done?

The mathematical solution to the problem was given by Daniel Bernoulli, a Swiss mathematician of the 18th century and a winner of the French Academy Award ten times. The first, to my surprise, was for a clepsydra (water clock) to measure time at sea. (I’m looking for specs of the clock and any assistance would be welcomed.) The many awards were not always a source of happiness. In 1734 he won the Academy Award with his father, Johann Bernoulli, a mathematician in his own right. The father couldn’t bear the shame of being equivalent to his son and banned Daniel from his house and did not reconcile with him until his death. I doubt that Joseph Cedar (Israeli movie director) was aware of the Bernoulli’s story, but the similarity to the movie “Footnote” is striking. The most important work of Daniel Bernoulli is hydrodynamics released in 1738:

Despite extensive research (I found six different studies!) that indicates that students of Physics and Engineering have conceptual difficulties to understand Bernoulli’s equation, I will challenge my readers with the solution of the water clock problem.

Bernoulli equation states:

Where :

P is the pressure.

rho is the water density.

g  is the gravitational acceleration~ 9.8 m/s2

h is the water height  above a reference plane.

v is the water velocity.  

He/she who wants to go deeper can go here and there are four lessons which I recommend at khan academy. Our problem looks like this:

We can write the Bernoulli equation:

 

Where  P1 is the pressure in the beaker, h1 is the height of the water in the beaker and v1 is the water flow velocity in the beaker. Respectively the pressure in the onyx is P2, h2 is the water height in the onyx, and v2 is water flow velocity in the onyx.  However, the beaker and the onyx are both open to the atmosphere. Thus P1 = P2 = 1 atm and can be removed. The water level in the beaker is h(t) and depends on time because when the water flows through the onyx to the base, h will be reduced. However, the onyx water height was determined as the reference plane and hence h2 = 0. Rearranging:

Since the onyx is very narrow in comparison with the beaker, we can assume that the flow in the onyx is much faster relative to the water velocity in the beaker  and can be neglected for the calculation of the water velocity in the onyx:

 

If this looks somewhat familiar, it is because this is Torricelli law and I used to run some very nice experiments with my middle school students at Beit Hashmonai:

Torricelli law, three identical holes at different heights

The amount of water through the onyx must be equal to the amount of water lost by the beaker:

Where A2 is the cross-section of the onyx  and A1 is the cross-section of the beaker:

Where r2 is the radius of the onyx. However, A1 is a function of time since the radius of the beaker is not constant but gets narrower at the bottom:

The velocity v1 is the change in the beaker water height:

We combine the last five equations:

Rearrange and make sure that the rate is constant (This is the reason for the whole exercise!) or:

For dh/dt to be constant, the radius of the beaker must be equal to the fourth root of the water height.

These mathematical tools were not available to al-Jazari. There is no evidence in the “Book of Knowledge of Ingenious Mechanical Devices” to the extensive mathematical knowledge that was available in the Muslim world of the 12th century.  I suspect that the mathematical education of al-Jazari was rather limited. This is a different topic and I hope to write a separate post in the future.

However al-Jazari was very resourceful, he developed a practical technique that allowed him to overcome the lack of mathematical tools. While preparing the beaker, he filled it with water and observed the outflow of the water with a reliable clock. If the float sank to the second mark, then the beaker radius is correct else al-Jazari hammered the beaker to widen it or make it narrower. Then the water is emptied from the beaker. The process was repeated for each mark. It is a pity that we do not have the beaker al-Jazari hammered to compare it to the theoretical calculation. One must admire the practicality of al-Jazari solution.

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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”

Introduction

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.”

Also:

“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.”