Al-Jazari Water pumps and Patents

Introduction

Category V deals with water pumps or in the language of al-Jazari “On machines for raising water from pools and shallow wells which are not deep, and from running streams.”

Al-Jazari is a man of few words, and his introductions are quite minimal, but in this chapter, he dives straight to the point. His opening line is: “I have shown the picture of that (machine for lifting water by an animal who turns a lever) after the text of the next chapter”. There is nothing about the current state of things, what were the pumps available in his time, what drove the need for improvements?  Nor any other introductory remark. However, the first two pumps are an improvement and automation of the Shaduf (شادوف) or in Hebrew קילון (kilon). This is a manual device for raising water, known to man for thousands of years. Al-Jazari design includes three improvements: mechanization, significant efficiency improvement and the use of segmented gear. Nowadays an engineer would write at least three different patents. This would lead us to a discussion of patents and al-Jazari.

Shaduf

The Shaduf is a hand-operated device for lifting water. We do not know who or when was it invented, but it was in use in ancient Egypt and Mesopotamia to irrigate land for thousands of years. Surprisingly enough, it is still used today in India, Egypt, and some other countries

The Shaduf consists of an upright frame on which is suspended a long pole, at one end of this pole hangs a bucket or a ladle. The other end carries a balancing weight which serves as the counterpoise of a lever.

With a relatively small effort the operator lifts the bucket or the ladle and carry water from a body of water (typically, a river or pond) onto the irrigation system. From this point, the water will flow to the crops in the fields due to gravity. The operation of the Shaduf is completely manual, but it’s easier to pull the rope down using the balancing weigh than lift the water. Moreover the Shaduf transport the water to the beginning of the irrigation canal. It is interesting to note that the Shaduf appears in old Hebrew text, The Mishnah “study by repetition” is the first major written collection of the Jewish oral traditions. It was sealed at the beginning of the third century AD. I did not find a translation, so this is my rough translation that does not capture the beauty of the ancient Hebrew:

 

“משקין בית השלהין במועד ובשביעית, בין ממעיין שיצא כתחילה, בין ממעיין שלא יצא כתחילה; אבל אין משקין לא ממי הגשמים, ולא ממי הקילון.” (משנה: מועד קטן, פרק א)

“Water an irrigated field during the festival and sabbatical, both from a newly-emerging spring and from a spring that did not just emerged. But do not water the field with water from rainwater or Shaduf water.”

Shaduf, a photograph from Eygpt, 2001

How does it work?

The first two water pumps of al-Jazari are relatively simple machines comparing to the complexities of the clocks and automata explained in previous posts. A-Jazri dedicated one page each. I placed the two drawings side by side. The technical explanation, as always, will be colored in blue, so anyone who is not interested in segmented gear or runged wheel can skip those bits.

The first two pumps designed by al-Jazari. The left pump has a single ladle. A single page from a dispersed copy, dated to 1315. The right pump includes four ladles. Topkapi copy, 1206.

We shall start with the diagram on the left of the pump that has one ladle. In the top room, a donkey is rotating the main shaft and the toothed wheel connected to it. The later rotates a toothed wheel in 900. Today we would probably use beveled gear for this purpose, but al-Jazari gives no details. My love M. complained that in the drawing you could not see the gears pressed against each other and the segmented gear which I shall explain in the next paragraph are perpendicular to their real direction. All these issues and more are related to the drawing made in the 12th century. In the future, I hope to add animations that will help my current readers to understand the mechanism. On the same axle, there is a segmented gear with the same cogs and spacing. However, only a sector of the circular gear has cogs on the periphery, in this case, a quarter of a circle. This segmented gear fits into a runged wheel which is connected to the axle of the ladle. When the cogs interlock with the stages of the wheel, they rotate the axle, and the ladle lifts about 15 liters of water at a time.  After a quarter of a circle, there are no more cogs, and nothing to prevent the runged wheel to rotate backward dropping the ladle into the water and the process repeats itself. The pump to the right is identical in its mechanism only there are four ladles and four segmented gears. That means that each donkey rotation will result in 60 liters. The efficiency improvement is probably less than 4x because the donkey will be slower because of the heavy load.

Efficiency

This chapter is quite unusual in the book because it deals with the engineering core, improving process efficiency, while most of the chapters are about surprising automata and rotating peacocks. The question of efficiency for most machines of al-Jazari is out of place if not completely from another discipline. The question of efficiency is an essential component in any engineering process. A process is efficient if we increase the amount of work performed while reducing the use of resources (raw materials, labor, fuel, time, etc.) Al-Jazari is an engineer by nature (Hebrew) and when the subject is water pumps he designed a significant efficiency improvement.

Al-Jazari and patents

In our world, the mechanization of the Shaduf justifies a patent, the improved efficiency by approximately 3-4 justifies another patent. There is a question mark about the inventor of the segmented gear. Some claim that segmented gear appeared 1st in the “The Book of Secrets” by Ibn Khalaf al-Muradi other give the invention to al-Jazari. I hope to obtain “The Book of Secrets” and then I’ll be able to formulate my own opinion.  I think that if al-Jazari was aware of this discussion, he was really surprised.

The official history of Patents starts with the Venetian law from 1474:

“Any person in this city who makes any new and ingenious contrivance, not made heretofore in our dominion, shall, as soon as it is perfected so that it can be used and exercised, give notice of the same to our office of Provveditori de Comun [State Judicial Office], it being forbidden up to 10 years for any other person in any territory and place of ours to make a contrivance in the form and resemblance thereof, without the consent and license of the author.”

Although the present patent laws are more complex, the essence practically identical:  The patent system is protecting inventors so that they will have an opportunity to receive proper compensation for their efforts. Why patent law was necessary in Venice in the fifteenth century and was not necessary in Diyarbakir in the twelfth century?

The need originated because of the emerging glass industry. Master Angelo Barovier in mid-fifteenth century invented the method to create clear glass, which was pure like rock crystal called ” cristallo”. This recipe was one of the most closely guarded secrets of the Venetian Republic for centuries.

Of course, if another manufacturer would be allowed to copy the recipe with minimal effort,  the willingness to invest in innovation and development will be diminished. Today patents are a major concern in high tech and pharmaceutical industry, but there was a time when mirror production was in the front of technology.

Venetian Goblet from the 16th century. Louvre Museum collection.

The world of al-Jazari was very different. This is not a sophisticated industrial world where multiple manufacturers were competing for everything including know-how and technology. The question of commercialization of knowledge is not relevant. The world of programming evolved differently. In parallel to proprietary knowledge and patent protection, there is the Free and Open Source Software-FOSS. The cornerstone of the movement is promoting cooperation between people, using computers. You can almost say that al-Jazari is precursory of the open source movement only with pumps and automata. This is not my assessment but facts. The following quote is from the book introduction as translated by Donald R. Hill.  The quote is a little long, but speaks for itself about his motivation of sharing his knowledge:

“I am in the service of the king Salih Nasir aI-DIn Abi al-Fath Mahmiid bin Muhammad bin Qara Arslan bin Dawiid ibn Sukman bin Artuq, the king of Diyarbakir, may God preserve him with those whom He chooses to preserve. That is following my service to his father and his brother, God sanctify their souls, before the kingship passed to him – a [total] period of twenty-five years, the first of them year 577. God, may He be exalted, has singled him out with distinctions of intelligence, high-mindedness, justice and probity, so that he surpasses in justice and probity the kings of the present age, and excels the lords of near and far in beneficence and graciousness…. I never began to construct a device of mine without his anticipating

it [i.e., its purpose] by the subtlety of his perception. He is completed by the refinement of his opinion and his wisdom. I was in his presence one day and had brought him something which he had ordered me to make. He looked at me, and he looked at what I had made and thought about it, without my noticing. He guessed what I had been thinking about, and unveiled unerringly what I had concealed.

He said ‘you have made peerless devices, and through strength have brought them forth as works; so do not lose what you have wearied yourself with and have plainly constructed. I wish you to compose for me a book which assembles what you have created separately, and brings together a selection of individual items and pictures’.”

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.

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 few modern reconstructions of it, some in different exhibitions and museums, but also in the Dubai Mall. It has a variety of animations in 2D and 3D, and it has a Wikipedia entry of its own. Due to the complexity of the mechanism, I divided this post to 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 in this clock.

The Elephant clock, manuscript from 1315, Syria

What does The viewer see?

An elephant,  approximately one meter and twenty centimeters long, carries on its back a canopy with four pillars and a castle. On top of the castle’s dome, there is a bird. Inside the elephant, there is a hidden water reservoir and a sinking float(a float with a hole which sinks slowly) during half an hour. More details in the next post. In the canopy sits a scribe holding a pen pointing at semi-circle with tick marks. During this half an hour the scribe rotates and his pen indicating the minutes passed. At the end of the every half an hour, the scribe will return to its original position. At the same time, there will be quite an impressive show. Between the elephant shoulders, ride a mahout (the elephant keeper and driver). In his right hand, there is an ax and a mallet in his left. Every half an hour the mahout will strike 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 like he keeps them from opening their beaks. Once every half an hour, he would raise his hand, right or left and the Falcon will emit a ball. The ball falls to the Dragon’s maw, make the dragon swing on its axis and lay the ball on the cymbal in a jar. Also, the bird on the dome will go spinning. Above the head of the Falconer (falcon trainer), there is a semi-circle with fifteen black holes. Every full hour one hole will be colored white, thus indicating the passing hours since sunrise.

You can see a short video demonstrating the elephant clock and explaining the mechanism. A fuller explanation in the next post.

Why an elephant?

In Wikipedia, the Elephant water clock entry, it says:

“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 is attributed to al-Jazari himself. I am afraid that the whole concept of multiculturalism is completely foreign to the 12th century and al-Jazari. The quote certainly is not by al-Jazari, but whoever wrote it (who?) explained the wealth of the clock. It made me think, and first of all about the elephant.

The Middle Ages and strange elephants

The trade routes in the middle ages were spread over Europe and the Middle East but also in India, China, and  Africa. On the East coast of Africa, they traded ivory, gold,  ebony, and slaves. China exported silk and porcelain and India spices and drugs. It means that rumors about elephants, giraffe, and other exotic animals reached Europe but the artists that drew the manuscripts had never seen an actual elephant drew them based on his 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 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 “firsthand”  copy. You can see that the elephant looks like an Asian elephant and the mahout and the canopy are located right. The acquaintance of al-Jazari with elephants is not necessarily surprising, although I couldn’t find any evidence for elephants in Diyarbakir. Arab rulers held menageries or collection of exotic animals. In addition to the curiosity and pleasure they provided, they demonstrated the wealth and the power of the ruler and demonstrated 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 from Nubian people to provide Egypt with three hundred and sixty slaves annually and wildlife. It This was the primary source for giraffes in the Sultan of Cairo 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 weight:

  • Freshness (something new)
  • High skills
  • Sense of danger
  • Magical picture

I looked at several iconic circus shows such as Jules Léotard, a French acrobatic performer that made history as the first man ever with the aerial act on a trapeze. It must certainly meet the requirement for ” Freshness or something new.” 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, high skills – Léotard practiced its aerobatic 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 act and flips between five trapezes with only a pile of mattresses to protect him. The elephant clock also demonstrates high proficiency and skills both to the innocent and skilled observer: 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), the virtuoso swing of the dragons. All are innovative engineering tricks demonstrating al-Jazari skills in water clocks and automatons. The crowd in the circus was afraid for Léotard life, and the sense of danger, which automatons be definition lack, intensified the experience.

Jules Léotard, a French acrobat, 19 century

Last but not least, the 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.

The Scribe Candle clock, on clock face and hands

Introduction

The Scribe candle clock is the second scribe holding a pen out of three scribes that appear in the book. The scribe rotates continuously and passes fifteen degrees every hour, so one degree (one marking) is approximately four minutes. We already met a scribe holding a pen in the elephant water clock (in Hebrew), and soon I hope to write on the beaker water clock that has a different mechanism, but a very similar scribe. The scribe and his pen are used as a hand in a clock. It reminded me “modern” analog clocks and made me go back and examine the development of concepts such as minutes and seconds and the development of the clock dial.

The candle clock of the scribe ” Book of Knowledge of Ingenious Mechanical Devices” Topkapi manuscript, 1206.

How does it work?

Al-Jazari opens this chapter:

“I came upon a clock made by Yunus al-Asturlabi which had the appearance of the clock I described in the first chapter[ meaning the candle clock of the sword men]. A cross-beam which had a hole in its center for the wick replaced the cap which I used to hold the candle down, and I discovered that the wax flowed into the interior of the sheath and over the instruments inside the sheath. .. This gave much trouble; for this reason the design was useless. “

We do not know who Yunus al-Asturlabi was. Eilhard Wiedemann, a German physicist, one of the first researchers of science in Islam, who did much to bring the work of the al-Jazari to the west, suggested the astronomer and mathematician Ibn Yunus. Probably we will never know for sure. Correct identification or not, it is quite interesting because we have no evidence of any sophisticated candle clocks before al-Jazari’s.

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 by the book translator and annotator Donald R. Hill with my captions:

A drawing of the mechanism by Donald Hill with my captions

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 its highest. 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. A string which turns the scribe is attached to the bottom of the weight. Every hour the scribe and his pen will cover 150, so one can tell the time within 4 minutes. 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.

Minutes and their measurement

The globe and the clock face owe their divisions to a numerical system which is four thousand years old. The Babylonians made astronomical calculations using Sexagesimal (base 60) numeral system.  We can only conjecture why people of the ancient Middle East (Assyrians were also Sexagesimal ) adopted the use of base 60. One assumption is that the number 60 was chosen because it is the first number divisible by all the numbers 1 to 6. Alternatively, base 60 was preferred because the lunar year contains three hundred and sixty days. There are more suggestions. Hipparchus of Nicaea already mentioned here(Hebrew), as well as other Greek astronomers, used the tools previously developed by the Babylonians astronomers.  Hipparchus used the geometry of a sphere to find locations on Earth. There were attempts to use grid lines before, but he was the first to apply rigorous mathematical principles to the determination of places on the Earth’s surface, by specifying their longitude and latitude in terms of 3600 running South to North(longitude) and parallel to the equator(latitude).

Claudius Ptolemy considered the most famous astronomer of antiquity. His book the Almagest, from Arabic  (المجسطي) is considered to be one of the most influential scientific texts of all time. Its geocentric model whereby planets revolve around Earth was accepted for more than twelve hundred years until the work of Nicolaus Copernicus in the 16th century. Ptolemy used and expanded the work of Hipparchus by subdivisions of 3600 of longitude and latitude into smaller sections. Each degree was divided into sixty parts called “partes minutae primae” literally “the first small part.” This was later reduced to minutes. The minutes were further divided into sixty “partes minutae secundae” or “second small parts.” Later reduced to seconds.  Interestingly enough the time units in Hebrew “DAKA” and “SHNIYA” reflect the historical names.

Clock still didn’t show minutes and seconds for hundreds of years after the Almagest, partly because of technology limitations and partly because there was no need. In the middle ages, the meaning of an hour as sixty minutes was not understood by most people. Not many mechanical clocks from the fourteenth century are left, but those I could find do not have hands, in most cases, and ring a bell to indicate the hours.

The Salisbury cathedral clock is said to be the oldest working clock in the world. It is dated to 1386 (not certain). It is a large iron-framed clock without a dial and obviously with no hands. There are other clocks competing for this title. None of them has minutes’ hand:

The Salisbury cathedral clock

The Forchtenberg clock tower in a small town in south Germany is one of the oldest surviving mechanical clock towers. In contrast to the controversial dating of the Salisbury cathedral clock, the year 1463 is carved in iron. The only uncertainty; was the clock made at this date? Or could it be older and this is the first repair date? This clock has only an hour hand:

The Forchtenberg clock tower

Who was the first to install the minute hand? It is not clear, but the second hand has a story we know. Jost Bürgi was a Swiss clockmaker, a maker of astronomical instruments and a mathematician. He was employed at the Court William IV, Landgrave of Hesse-Kassel, a mathematician and astronomer by himself. Although now forgotten he was an outstanding astronomer, his observations, particularly those of the fixed stars, were at least as accurate as those by Tycho Brahe. Bürgi was brought to the court to develop scientific instruments, and assist in the observation that could confirm the heliocentric model by Copernicus. He built various instruments. In 14th April 1586, the count wrote to Tycho Brahe about a highly accurate clock which Bürgi had built which, for the first time, had a minute hand, a seconds hand and had an error of less than a minute in 24 hours! Christoph Rothman, another astronomer wrote about the new amazing clock:

“The duration of a second is not very short but resembles the length of the shortest note in a moderately slow song.

This quote commemorates a time when science and technology produce a new reality.

Bürgi precision clock

Epilogue

I read today about a new exhibition of Christian Boltanski in the Israel Museum called “life”. He wrote: [my translation from Hebrew]

“a major part of my job is the fact that each person is special, one-of-a-kind and important, each will finally vanish. Most of us will be forgotten in two generations, with the passing of those close to us. “

It’s certainly not true for al-Jazari but probably true for most of us. The exhibition combines early works of Boltanski alongside new works and includes a digital timer continually counting the seconds from the moment of birth of the artist. I found a photo of a timer installation of Boltanski at the Biennale. I don’t know if the installation in the Israel Museum is identical.

Christian Boltanski, the Venice Art Biennale, 2011.

 

 

The automaton of a slave girl holding a glass of wine and slaves in the Artuqid Palace

Introduction

It is a decorated wooden cupboard by the king’s side during the feast. It has a door with two closed leaves. Every seven and a half minutes the doors would open and reveal an automaton (a mechanical device made in imitation of a human being) of a slave girl holding in her right hand a glass filled with wine and in her left a small towel. The king takes the glass, drinks the wine it contains, puts the glass back in her hand and, if he wishes, wipes his mouth with the towel. Then he closes the door leaves on her.  This process will repeat itself every eighth of an hour.

We met slaves and slave girls here and here(in Hebrew), but a quick search of the” Book of Knowledge of Ingenious Mechanical Devices ” reveals ten different chapters mentioning slaves or slave girls. This seems a lot! I went to study slaves in the Islamic world in the twelfth century and how similar or different it is from al-Jazari’s book. To my surprise, my journey led me to Cairo Geniza.

Automaton of the Slave Girl, Serving a Glass of Wine”, a folio from Syria or Iraq, 1315

How does it work?

The technical explanation, as always, will be colored in blue, so anyone who is not interested in an inclined plane or a tipping bucket can skip those bits. To understand the mechanism, I use a drawing by the book translator Donald R. Hill with my captions. The slave girl became a boy? I guess Hill or his illustrator did not think that gender was important?

A drawing of the mechanism by Donald Hill with my captions

The cupboard is about 1.6 meter (originally six spans, in Arabic شبر or shabr) and width of approximately 60 cm. There is a wine reservoir above the cupboard which is dripping slowly to the tipping bucket below. I already discussed the tipping bucket here. The tipping bucket fills in seven and a half minutes (eighth of an hour) and discharges all at once into the glass in the slave-girl’s hand. The glass becomes heavy enough to lower the hand of the slave which is on an axis, lifting the extension rod from the docking station.

The slave-girl will roll down the inclined plane and pushes the left leaf with her left hand, which is holding the towel like she is offering the wine glass to the king. The king takes the glass from her hand, drinks its contents, and if he wishes, wipes his mouth with the towel. Then he puts the glass back in her hand, presses it down, and pushes the slave girl gently until she docks. This process will repeat itself every seven and a half minutes as long as there is wine in the reservoir.

Slaves and girl slaves in the “Book of Knowledge of Ingenious Mechanical Devices “

In ten chapters of the “Book of Knowledge of Ingenious Mechanical Devices “ slaves are mentioned:

  1. Category I, chapter seven – The candle clock of the swordsman(Hebrew): An automaton of young black (غلام),  with no beard holding a sword to shorten the candle wick.
  2. Category  II, chapter three – An arbiter for drinking parties: An automaton of a young a slave girl ( (جَارِيَة‎) in Wikipedia also a concubine)  with a  bottle and a glass as well as four slave girls in the balcony.
  3. Category II, chapter four –The musical boat: An automaton of a musical boat with a slave holding a jug and goblet, and four slave girls, flute-player, a harpist and two tambourine-players. I believe that they are “qiyan” – educated girls and women who entertained and entranced the caliphs and aristocrats. I already wrote about them here (in Hebrew)
  4. Category II, chapter seven – A slave holding a Fish and a Goblet: An Automaton of a young slave pouring wine
  5. Category II, chapter eight – A man holding a goblet  and a bottle: An automaton of a slave pouring wine into a goblet
  6. Category II, chapter ten –A slave girl emerges out of a cupboard with a glass of wine: (The current post) Automaton of a slave protruding from a cupboard with a glass of wine.
  7. Category III, second chapter- al-Jazari’s motivation to make the automatic pitcher is written explicitly: ” King Salih, may God double his righteousness, disliked a servant or slave-girl pouring water on to his hands for him to perform his ritual ablutions and he wished me to make [something] for pouring water onto his hands for his ritual ablutions.”
  8. Category III, third chapter – A  slave who pours water over the king’s hands: An automaton of a  slave who pours water over the king’s hands.
  9. Category III, ninth chapter – A basin of the peacock for washing the hands (Hebrew): Automaton for washing, one with soap, the other with a towel
  10. Category III, chapter ten- A basin of the slave for washing the hands: An automaton of a kneeling slave holding a water pitcher in his right hand

Cairo Geniza and slavery in the twelfth century

Do we know who were the slaves and the female slave? How they were enslaved and what kind of life did they have?

Cairo Geniza (storage) is a large collection of Jewish manuscripts and fragments written between the ninth century and the nineteenth century and preserved in the attic of the synagogue in Fustat or old Cairo. Maimonides, while in Cairo, used to pray in this synagogue, and it is therefore also known as the Maimonides synagogue.

In my ignorance, I thought the Geniza was for damaged Bibles and holy books but apparently because the Hebrew language was considered sacred they saved everything: court documents, bills of sale, and the correspondence of the local Jewish community and more. Craig Perry wrote his doctoral thesis: “The Daily Life of Slaves and the Global Reach of Slavery in Medieval Egypt, 969-1250 CE” based on materials from the Cairo Geniza. This is not the story of the slaves in Diyarbakir palace where al-Jazari worked, but we can learn a lot.

In an undated letter from the Cairo Geniza, a local court in the Red Sea port of Aydhāb (today in Sudan). Two slave women appeared before the Qadi (Muslim judge), one of them testified that they were kidnapped when they went to fetch water at a local well and sold into slavery. The Qadi asked if they were Muslims? Because according to Islamic law, Muslims were ineligible for enslavement. One of the two insisted that she was Jewish and therefore the case was transferred to a Jewish court. The writer of the letter asked for advice from Fustat about how to handle the matter. His decision to consult with associates explains how this document came to be preserved in the Genizah. We don’t know what happened to the unfortunate women but this is an example of how women were enslaved, and there is a wealth of information about buying and selling of individual slaves.

The second way I already mentioned (in Hebrew) is diplomatic exchanges: for instance, the Egyptian historian Al-Maqrizidescribes  large processions of male and female slaves arrived in Cairo from regions to the south, the first one at 1023 CE:

“On Tuesday, when eight days remained in the month the gift of Ibn

Makārim b. Abū Yazīd arrived from Muḥdathah in Aswān, and it was:

twenty heads of horses, eighty fine camels, a number of black [slaves], females and males, a cheetah in a cage, Nubian goats, birds, monkeys and elephant tusks. “

Prestige gifts of slaves were not limited to Nubia. The Fatimid Caliph al-Mustanṣir Billah received gifts of Turkish slaves from the Byzantine emperor Michael IV, slaves, and eunuchs from the Amir of Yemen and slaves the ruler of al-andalus(الأندلس), the Muslim kingdom of Iberia.

The near constant warfare at the edges of the Islamic empire produced a steady supply of prisoners-of-war and  “wholesale” slave trade.

We don’t know if the slaves in the Palace in Diyarbakır came as a gift from another ruler, purchased individually, or captured during a war.

The bills of sale contain a wealth of information that is useful for reconstructing the geography of slavery, Allowing Perry to do the statistics on the origin of slave girls, horrifying as it may sound. Perry found a large majority of Nubian slaves along with quite a few slaves from other sources:

It is impossible to know, of course, the origin of the slaves in the Palace in Diyarbakır but the Geniza documents cover slave trade in the entire Middle East, and it is reasonable to assume that that is was not very different.

When I think of slaves, I think of hard work in the cotton fields or the sugar plantations in South America. The Islamic world of the 12th century was not associated with large-scale agricultural production. The use of domestic slaves reflects the relative wealth and urban nature of the Muslim elite. Families of merchants, judges, scholars, and others were able to purchase slaves to help with raising the children and household chores. This is evident from the Geniza and is very similar to the book of al­-Jazari. All the slaves in the book are part of the Palace household, helping with daily tasks or helping during the feast.

Slave women were frequently used as child-bearing concubines by Muslim men. According to Islamic law, children born to a Muslim master and a female slave were free-born Muslims. The Fatimid  Caliph al-Mustanṣir Billah, already mentioned, was the son of Sudanese slave named Rasad. That was not the situation in the Jewish community where the Rabbinical establishment struggled to deal with the phenomenon, but that’s another story. I completely Ignored the topic of slave soldiers. This is essential to the history of the twelfth century but is not part of al-Jazari’s book.

Epilogue

My deep connection to al-Jazari makes me want to apologize on his behalf because of the casual manner in which he relates to slavery. It is more painful due to human rights situation in Israel and the general feeling that human rights are under attack.

This is childish; you can’t throw me and the education I received at home and in  Hashomer Hatzair” (a Socialist-Zionist, secular Jewish youth movement) to the 12th century. While I was searching for information on slavery I found  a text by Benjamin of Tudela  which for me was always just a happy song  (in Hebrew) by “HaGashash HaHiver”, an iconic Israeli comedy trio:

” And from there (Aden) to the region of Aswān is a journey of twenty days through the desert. This is Sebā on the Nile River that descends from the land of Kush. There are some among the Kush who have a king and they call him the sulṭān al-ḥabash. There is a people among them that are like animals that eat the grasses that grow on the bank of the Nile and in the fields. They go about naked and lack the intelligence of human beings. They lie with their sisters and with anyone they wish. (Sebā) is very hot. When the people of Aswān go raiding in their land, they carry with them bread, grain, raisins, and figs. They throw this toward (these people), who come to get it. They obtain many prisoners and sell them in Egypt and all of the kingdoms around them. These are the black slaves, the sons of Ham.”

This is more documentation (?) of capturing slaves in Nubia, but the reference to slaves is chilling and I’m afraid that it tells more about Benjamin of Tudela and his lack of ability to see another human suffering then it tells about the poor enslaved Africans. I would like to conclude with a line from the Universal Declaration of Human Rights:

“All human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood.”

universal declaration of human rights, December 1948

 

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.”

Al-Jazari and Versailles Fountains

Introduction

There are six different fountains in The Book of Knowledge of Ingenious Mechanical Devices. This seems somewhat excessive. I suggested in a previous post that this can be explained by the importance of gardens in Islam. However there is another option; Throughout history, rulers asked their engineers and artists to create tangible displays of their power and wealth to impressed their allies and intimidate enemies. The Versailles fountains is an extraordinary example of ignoring cost and engineering complexity to demonstrate power and control. I will elaborate below.

Versailles Fountains, unknown photographer, Wikipedia Commons

The six Fountains of al-Jazari- How do they work?

Combined Drawing, Six Fountains, Topkapi manuscript, 1206

The technical explanation, as always, will be colored in blue, so anyone who is not interested in tilting pipes and floats can skip those bits. I wrote about the first fountain here (in Hebrew). The second fountain has an identical mechanism. The only addition is an extra delivery pipe, so when one fountain is producing a single jet the other fountain is throwing six arcs, and after an hour they switch, and the fountain that was producing a single jet is throwing six arcs and vice versa. The other fountains have a different mechanism, producing different water jets and have different timings. However, there is a lot in common:

  1. All fountains operate by the force of gravity. A house was built at some distance from the fountain and water were raised to a sufficient height to provide the jets. One of al-Jazari pumps, from category V, was probably used for this purpose. Raising the water and their transport are not included in the drawings.
  2. All fountains include a change in the water flow direction. In five out of six this is accomplished using a pipe that could tilt. This is a drawing from the book, and I added labels for clarity.

    Tilting pipe, First Fountain, Topkapi manuscript, 1206

    The water flows into the bowl welded to the transverse pipe that can be tilted (tilting pipe). The pipe is slightly more heavy on the side of tank A, and the water respectively flows into water tank A and water flows from the two right openings. Most of the water ran from the main opening to the right tank. The smaller opening has an onyx mouthpiece and will fill the tipping bucket slowly. At the right time, the tipping bucket would tip and push the tilting pipe upward, shifting the flow to tank B.

  3. All the fountains of al-Jazari had a time-based control system. Today It’s trivial to control the fountain with a microcontroller and computational power, or timing requirements are simple engineering task in comparison to any mobile phone. In the twelve century, it was a significant engineering challenge, and al-Jazari offers a variety of solutions. I have explained already the tipping buckets in the first two fountains. Fountain three and four utilize floats for the control mechanism:When the pipe is tilted to the right, the water will flow into tank A. The plug is closed so the flow to the fountain head is blocked and the tank will fill. The float is limited to the corner but it free to move up and down and will rise with the rising water. After fifteen minutes the float will lift the pipe extension, and the pipe will tilt to the left. The swing of the pipe will pull plug A’ opening the water path to the fountain head. At the same time, water will begin to flow to tank B, and the plug will seal the water flow from tank B.
  4. All six fountains of al-Jazari end with two concentric pipes and different end units. In the post about the first fountain I showed how al-Jazari generated a single jet upward, followed by six jets in a shape of arcs but there are many more options:

    Drawing of an alternative end unit. The fourth fountain, Topkapi manuscript, 1206 with my labels

The water flows in the inner pipe that is connected to tank A. The water shoots out from the inner pipe with force into the shield and descends from its perimeter like a “tent”. When the water switch to tank B, it will flow in the outer pipe generating six (in the drawing you see only two) arcs.

The Power of the ruler and the amazing story of the fountains of Versailles

I hope that my summary of the fountains shows how much thought and effort went into fountains’ engineering by al-Jazari like the Banu Musa before him. In a post (in Hebrew) about the controversy with the Banu Musa, I assumed that al-Jazari deep interest in fountains is related to the importance of gardens in Islam. However, there is another option, after all, grandiose fountains are not limited to medieval Muslim engineers.

Louis XIV built Versailles (Château de Versailles), one of the greatest achievements in French 17th century art and the emergence of the Rococo style, not only as a place of residence for the Royal family but as a part of an elaborate plan to centralize the French government and form absolute monarchy. To accomplish this, he placed the palace outside Paris, forcing the nobles to spend time at Versailles, becoming his captive guests. He has spent ridiculous sums of money in design, with gold trim and built the gardens of Versailles with many fountains. Some claim that the central political structure in France today is the result of his actions. Either way, Versailles became a source of envy and admiration from other Royal houses, and Louis XIV was the most powerful King in Europe. The story of Versailles fountains is less known.

The water challenge appeared began as more and more fountains were added. Originally water was pumped into the gardens from ponds near the château. However, there was never enough water to keep all the fountains running at the same time. Jean-Baptiste Colbert, the French Minister of Finances and notable politician, put aside the kingdom business and came up with a system by which the people who maintained the fountains would signal each other with whistles upon the approach of the king so the fountains on the route of the king will be functioning… The most ambitious project was to bring water from the river Seine. The pump was called  “Marly Machine” (machine de Marly)

Nicolas de Fer, 1720, Marly Machine

Pump power was provided by 14 water wheels, each 12 meters in diameter, driving a total of 257 pumps. The most remarkable aspect of this array was that the wheels not only drove directly connected piston pumps but also transmitted power 650 meters up a hill from there, the water was distributed by an aqueduct and pipes.

.Overstating the size of this project is impossible. It could happen only in a courtyard entirely isolated from the realities of life of the people.  A staggering workforce of 1800 employees for seven years was needed to construct the machine, more than 100,000 tons of wood, 17,000 tons of iron and 800 tons of lead.

This text, like other texts on fountains, tends to use numbers to praise and glorify the fountain. The little Prince thought it was a problem of Grown-ups :

“Grown-ups like numbers. When you tell them about a new friend, they never ask questions about what really matters. They never ask: ‘What does his voice sound like?’ ‘What games does he like best?’ ‘Does he collect butterflies?’ They ask: ‘How old is he?’ ‘How many brothers does he have?’ ‘How much does he weigh?’ ‘How much money does he have?’ Only then do they think they know him. If you tell grown-ups, ‘I saw a beautiful red brick house, with geraniums at the windows and doves at the roof…,’ they won’t be able to imagine such a house. You have to tell them, ‘I saw a house worth a thousand francs.’ Then they exclaim, ‘What a pretty house! “

I think fountains draw out of us more “numbers” than most things. If you are like the Little Prince and numbers are not your cup of tea, you might still like to know that the amount of water delivered to Versailles was larger than the water consumption of Paris as a whole!  The machine suffered (of course) from frequent breakdowns, required a large permanent team of technicians and engineers to maintain her, but still survived the French Revolution and worked 133 (!)  years until 1817, the year of the invention of the bicycle. I haven’t found any evidence that Louis XIV, the Sun King ever saw all this as excessive or a waste. On the contrary, he showed it proudly to his guests, including the Tsar Peter the great, who was so excited, that he built the Peterhof Palace and gardens, near the Gulf of Finland, with Versailles as a model with the largest fountain complex in the world and called one of the building after Marly

This is not the end of extravagant fountains. The following is a quote from the website of the Dubai fountains and is also excelling in using numbers. Before anything else, this is a tourist site, but behind the words, you can still hear the fountain as  a symbol of power and control:

“The Dubai Fountain is the world’s tallest performing fountain.

At over 900 ft in length – equivalent to over two football pitches – The Dubai Fountain is situated on the 30-acre Burj Lake and performs to a selection of international melodies.

The fountain has a unique design comprising five circles of varying sizes and two arcs and features powerful water nozzles that shoot water up to impressive heights equivalent to that of a 50-story building…..The fountain performs to a range of different songs from classical to contemporary Arabic and world music. When operational, the fountain has over 22,000 gallons of water in the air at any given moment.

 

The Perpetual Flute and al-Jazari’s Library

Introduction

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

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

How does the flute work?

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

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

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

 

The literature survey and al-Jazari’s Library

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

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

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

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

 

Manuscripts and libraries in the golden age of Islam

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

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

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

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

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

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