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.

 

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.

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.”