In this article, Professor Yavuz Unat, a known historian of science from Ankara University, draws a general survey on al-Jazari and his treatise. He describes some of his machines and points out the numerous technological innovations brought about by al-Jazari in their design and physical principles.
By Prof. Yavuz Unat*
1. Al-Jazari and his encyclopedia of mechanics
Bedî‘ûz-Zamân Abû ‘l-‘Izz Ismâ‘il b. ar-Razzâz Al-Jazarî lived in Anatolia during the 13th century. He was originary from Mesopotamia. That region was called in ancient times Cezîre or Cizre (Jazîra in Arabic). We have no other knowledge about his life, except the scanty notices contained in the introduction of his book. As we may learn from this, he was in the service of the Sultan of Diyarbekir, Al-Salîh Nâsîrüddîn Abû ‘l-Fath Mahmûd bin Muhammad bin Kara Arslan bin Dawûd bin Sukmân bin Artuq (ruled between 1200 and 1222), beginning from 1181, and before that he was in the service of his father and brother. 
On the demand of Sukmân bin Artuk, al-Jazarî wrote a work with the title Al-Jâmi‘ Bayna’l-Ilm va’l-‘Amali An-nâfi fî Sinâ’ati ‘l-Hiyal (The Book of Knowledge of Ingenious Mechanical Devices). This work, filled with practical information and theoretical insights on a wide range of machines, reached a high peak in mechanical technology. The machines described in the book are classified in six categories; the first three categories being composed of ten chapters, and the last three containing 5 chapters:
Category 1: Clocks  (10 chapters)
Category 2: Vessels and figures suitable for drinking sessions (10 chapters)
Category 3: Pitchers, basins and other things for hand washing and phlebotomy (10 chapters)
Category 4: Fountains and perpetual flutes ((10 chapters)
Category 5: Machines for raising water (5 chapters)
Category 6: Miscellaneous (5 chapters) .
When the work of al-Jazarî is analyzed, we see that he made various tools by using and developing the principles that have been known from the Greek mechanical tradition. These principles are air vacuum and balance principles.
In the Greek mechanical tradition, studies were made on air, vacuum and balance principles by Ctesibios (3rd century BCE), Philon (2nd century BCE) and Heron (1st century CE). As a result of these studies, machines were developed. Archimedes (287-212 BCE) should be considered among them. Some of these studies were translated into Arabic and their achievements were greatly developed in the treatises of Banû Mûsâ (9th century), al-Khâzînî (fl. about 1120) and al-Jazarî (13th century). Kitâb al-Hiyal (The Book of Mechanical Devices), written by Ahmad ibn Mûsâ, one of the three brothers Banû Mûsâ, is one the first detailed and original work on this topic to have been written in Arabic. In this book, Ahmad described a hundred devices of which the functioning was based on air, vacuum and balance principles. These devices are magical pitchers, fountains, lamps, tools that keep fixed water level, levers and bellows. For the construction of these machines, straight, double and curled siphons, valve control by buoy and air control mechanisms were used . A short treatise ascribed to the philosopher al-Fârâbî (874-950), Risâla lî-Abî Nasr al-Fârâbî fî’l-Khalâ’ (Article On Vacuum), hit on the subject of air and vacuum . Al-Khâzînî’s book Kitâb Mizân al-Hikma (Book of the balance of wisdom) is highly important in this regard. Al-Khâzînî changed the water gauge to an incredible balance tool and he made scales that he called “al-Mizân al-Jâmî‘” (Universal balance) . On the basis of this mechanical heritage, stemming from Greek and Arabic scientific tradition, al-Jazarî carried on the previous achievements in this field to an unprecedented peak. He did not expose in his long treatise the theoretical principles of the theories of air and vacuum he worked with, however his dexterity in making clever and intriguing devices shows how he knew the topic in detail.
2. Samples of machines made by Jazarî and working with air, vacuum and balance principles
Pitchers, which can pour the liquids filled in a requested way, are in the first place of the machines that were designed by al-Jazarî based on air and vacuum. He gave ways of making of six pitchers in his treatise. Some of these pitchers are:
Big brass pitchers which pours the water automatically for the ritual ablution of the king (Fig. 1) : When the bird sings on, the pitcher is brought near the king, water begins to pour from the beak of the duck. The king can then have his ritual ablution. The empty pitcher is then brought back; it is filled with water and brought again when it is necessary.
Pitcher with Peacock: The tool is the pitcher in the shape of a peacock (Fig. 2). The neck of the peacock rises from the level of the head and its tail is closed. The pitcher is used for ritual ablution. An appointed person pours water from the cover of the peacock tail into the peacock. When the circular nosing on the tail is pulled, sufficient water pours from the peacock bill for having ritual ablution.
It can be said that al-Jazarî developed considerably fountain mechanisms. Until his time, there were few excellent fountains as well made technically as those of Jazarî. There is no information about fountains in Heron and Philon. However, it is said that Vitrivius used some pipes to support water to the fountain. Fountains that have more complicated structure had not been made until Banû Musâ.
Although the fountains of al-Jazarî were similar with those of Banû Mûsâ in principle, they were more excellent on the technical level. Al-Jazarî was aware of his technical superiority and he made explicit criticisms to the models of Banû Mûsâ.
He described six fountains based on balance principle. Furthermore, his book contains four devices that are technically similar with fountains. However, they did not spout water, they were designed to make only a sound. Despite this feature, we can consider them among the typical models of al-Jazarî’s fountains.
Among those fountains we mention the one with two Tipping-buckets. It is formed from a tank that supports water and a fountain that is placed in the pool. Fountain spouts water like an arc for fifteen minutes then like a lily of the valley (Fig. 3).
The design of automata based on simulating the movements of the Moon, the Sun and living organisms on earth has a long history. Beginning from ancient times, mankind has believed that nature is alive and has thought that it could be aroused by the contribution of magic, charm or supernatural powers. Colored stones, strange figures and idols in caves are the oldest signs of this request. However, before the Greek civilization, the dolls with moving arms found in ancient Egyptian graves can be considered as pre-studies in this field. More complicated ones are seen in early Egypt.
Greeks had made more complicated automats. It is said that Daedalus (4th century BCE) had made a flying bird and a sculpture that protected the labyrinth by moving up and down and also Tarentumlu Archytas (4th century BCE) had made a bird from wood and this bird was made to fly with adequate mechanical principles. During Antiquity, studies on automata were developed in two ways: Tools of fine technology designed to amaze and amuse and utilitarian machines such as water clocks.
Of the first category, that of the devices created for fun and amusement, which were built on the basis of various physical principles of air, vacuum, water, blaze and balance, we find a variety of them in Greek works. The most important contributions were those of Ctesibios, Philon and Heron.
This trend of mechanical devices, centered on fine technology, continued in the Islamic civilisation. Samples of such machines are seen in the Kitâb al-Hiyal by Banû Musâ. Some of them include a horse that gets his head into bucket to drink water, oil lamp that can regulate the wick and oil level, and lamps that were not extinguished when turned forth to the wind.
3. Automata studies developed with water clocks
The oldest time measurement tools were the Sun, the sand and water clocks. Egyptians had benefited from the shadow length of the Sun for measuring the elapsed hours in the daytime. On this basis, they made simple reliable sundials which were also free of expense. However, those sundials require the Sun’s rays, consequently they could not be used in cloudy weathers and particularly not during the night. For this reason, the water clocks were called “horologium hibernum” or night clocks.
The common usage to which water clocks were applied is to announce the passing times from daytime or night. Various methods were followed in the technique, such as throwing a ball on a bell, tooting, banging big drum by timpanists, and of the movements of dancing toys. Consequently, automation studies had a great development related with water clocks.
Automata studies reached their highest point with al-Jazarî. In his book, he describes gives various samples of automata. Some of them are:
An arbiter for a drinking session: This is an automat that decides who will drink during a drinking session (Fig. 4). The device was made in the shape of a citadel with five stages. On the ground, a concubine sits while holding a bottle in her hand and there is a glass in front of her. On the upper stage there are four musician concubines. A dancer is on the upper stage and on the top stage there is a door with two leaves. On the citadel there is a dome and on the dome there is a horse and its rider located.
This automat was taken to meetings and put on the floor. After a while, concubines begin to play their musical instruments, the dancer begins to dance, and the rider begins to turn. Afterwards, the concubine begins to fill the glass from the bottle. The rider stops, and a snake presents the glass to the person who was pointed by rider. After the person drinks, he puts the glass in front of the concubine. This ceremony repeats for 20 times with 20 minutes intervals, then the leaves of the door on the top stage opens and a figure comes out from the door. His right hand says that there is no more to drink while his left hand points that there are still two glasses.
Basin with peacock for washing the hands
The device (Fig. 5) is composed from a basin that is placed on a base, four columns rise from the bottom of the basin and a citadel with two doors that carry the peacock on the columns. The neck of the peacock lies as an arc and its bill points to the basin. Its tail is straightened up. Water flows from the bill of the peacock; meanwhile one of the doors opens and a child comes out holding a soap jar in his hand. When the flow of water stops, the other door opens and a child comes out holding a towel in his hand.
4. Water clocks
The machines made by al-Jazarî about this topic are very interesting and very important for the history of technology. The water clocks chapters of his book are written with a high care and in a very sensitive way. Furthermore, he provided a profusion of details concerning their mechanism which he described in detail.
4.1. Elephant Water Clock
This clock is the most famous machine of al-Jazarî. It is in elephant shape and there is a chair on its shoulder, a citadel on the column of corners of chair, a small dome on the citadel and a bird on the dome (Fig. 6). A balcony is set on the citadel in the way of an elephant’s head. A man is sitting on the balcony, two falcons on the right and left sides of the man. Between the columns of the balcony lies an arm with two snakes twined on it, a hemisphere on the center of the chair and a platform on which the clerk holds a pencil in his hand. On the platform is situated an arc that is divided to 7 ½ degrees. A handler sits on the elephant neck and holds an axe in his right hand and a staff in his left hand. Two vases are on the two sides of the elephant neck.
When the pencil of the clerk comes to 7 ½ degrees in half an hour, the bird sings, half of one hole becomes white, the man sitting on the balcony lifts his hand up from the falcon bill on his right side and puts his left hand on the falcon bill on this left side. A ball falls from the falcon bill on the right side into the snake mouth on the right side; the snake brings the ball in the vase on to the right shoulder of the elephant, the handler of the elephant thrusts at the elephant head with his axe, he lifts his hand with a staff and he beats on the elephant head. The ball comes out from the elephant chest, a bell hanging on its belly falls and makes sound, and consequently it announces that half an hour passed. Pencil of clerk comes out of the degree sign. After, the same process repeats for the falcon and the snake on the left side. One hole becomes completely white. In this time one hour has passed.
4.2. Water clock with citadel that announces sun hours
This water clock of Jazarî (Fig. 7) is the Sun water clock that was divided into 12 for night time and to 12 for daytime. This clock is an astronomical clock; namely it indicates the location of the Sun on the sky in the daytime, the zodiac locations of the Sun and Moon in the sky and how many hours passed from daytime or from night.
This clock is in the shape of a house with the length of two people. On its bottom part there is a door with nine hand spans length closed with bronze or wood. There are two timpanists, two trumpeters, two bell players in front of the curtain on the ground part of the tool, there are two altars on the two sides of the curtain and one each falcons with open wings in the altars, two vases in front of the falcons and one each bell hanging in the vases, between two altars there are 12 glass disks arranged in a semicircle form that has convexity upward, a frieze on the altars and a crescent made from gold moving through the frieze, on the frieze 12 doors with the same colors and with one each leaf. On them 12 doors with two leaves are parallel with subjacent doors, on the doors a window where can be seen six of the 12 constellations, under it a circle that carries the Sun and under it one more circle that carries the Moon.
In the beginning of the day, a gold crescent begins to move regularly on the frieze. When it passes the first door and comes between the first and second door, leafs of the first door on the upper side open and a figure is seen, at the same time a subjacent door turns and its color changes. Two falcons come forward and get close to vases and they fall one ball each on the bells from their bills. They make a sound that can be heard from a long distance. In the 6th, 9th and 12th hours, additionally timpanists play their drums, trumpeters play their trumpets and bell players play the bells at the same time.
The Sun stands in the level of the constellation, on which it exists in the beginning of the day, to rise from the horizon. The constellation rising with the Sun slowly arises and the constellation against it sets.
As for the night; the Moon is seen in the same shape as its appearance in the sky at the level of constellation it locates, if it is a crescent it is seen as a crescent, if it is half a moon it is seen as a half moon and if it is a full moon it is seen as a full moon. From the beginning of the night, in an hour period, a light is seen that gets bigger until the first glass disk becomes completely luminous. When the sixth and ninth glass disks become completely luminous, musicians perform their works as in the daytime. When the twelfth glass disk becomes luminous, which is the end hour of the night, the same processes are repeated.
4.3. Water clock of the boat
This clock is a beautiful pot in the shape of a boat which is made of brass (Fig. 8). In the center of this boat, there stands a citadel in a square shape on brass columns and there is a small dome on the citadel. There is a door on the surface of the citadel which looks at a bow of the boat. From this door, the head and chest of the falcon are seen. There are two opposite beams between the columns. An arm passes from the center of beam. A snake tail twines to this arm. Snake head lies towards the falcon. In the center of the boat, there is a part which looks like a dome and on this part there is a chair where a clerk sits holding a pencil in his hand. On the chair, around the clerk 15 signs are made. The pencil moves on these signs and when it comes at the end of the signs, an equal time of day has passed. The falcon drops a bronze ball into the snake’s mouth. The snake goes down and puts the ball on a big bell in the bow of a boat and returns its place. The pencil of the clerk returns the first sign again.
5. Clocks with candles
The other group which is interesting for automation studies and had not been examined until Jazarî concerns the clocks with candles. Four models of this kind are described in Al-Jâmi’ fi sinâ’ât al-hiyal. One of them is given as an example below.
The device is a candlestick which has a glass cover on it (Fig. 9). On the bottom of the cover, there is a perch and on it there is falcon of which back and back head are adjacent to the cover. There presents a clerk holding a pencil in his hand on the right side of the falcon and on the chair the basis of the candlestick. At the beginning the pencil of the clerk is outside of the semicircle which is divided into fifteen pieces. The candle is lighted. Pencil point of clerk moves until it comes across the first sign. When the pencil reaches the end of fifteen degrees, a ball falls from the falcon bill to the basis of the candlestick. In this case it is known that one hour of night has passed.
6. Blood Letting Containers
Among the automat studies of al-Jazarî, there are blood letting containers which measure the blood quantity taken from a patient. No record is available before that time about blood letting containers. Al-Jazârî made four blood letting containers by using the balance principle. We give one of them as an example.
The tool is in the shape of a basin that is placed on a basis (Fig. 10). There stands a monk on the platform in the center of container. The monk holds a rod in his hand and one point of rod lies towards the edge of the container which is marked from 1 to 120. The tool is placed infront of the person whose blood will be taken. Blood is taken into the container. When 1 drachm blood is accumulated in the container, rod in monk’s hand reaches to first sign. When the blood quantity increases, monk turns with his rod to show blood quantity.Table Properties
7. Pumps for raising water
These pumps are used for taking water upward from lakes or wells. Al-Jazarî describes five of them. Below is one of them as an example.
As seen in Fig. 11, the pump is in the shape of a building that is placed in a well or lake. When the animal above turns, turbines move and with this movement the spoon enters into the water and takes water upward.
8. Palace Gate
Another important device created by al-Jazarî is the gate of Artuqid Palace (Fig. 12). This gate was 18 handspans length, namely four meters length and 6 handspans, namely 1.5 meters width and two leaves, and it was made of cast glass. The central part of the gate is in the shape of a frame that is composed from hexagon and octagon star motifs. This frame is surrounded by küfî writing that is embossed with twining foliage: “Domain Belongs to God Who is One and Certain”. This writing is surrounded by a framing which is embossed with polished one yellow and one red leaf. On the up side of the leaf of the gate, there is one glass sheet and on it there is an everlasting rainproof from cast glass which is a production of marvelous effort. The whole framework of the gate is surrounded with embossed glass cord. The closing part is in the shape of a smart column.
Al-Jazarî explains how he filled the first frame. Four blocks is cut from wood in the shape of a hexagon star, octagon star, almond and saddle; iron nails are made which are four inch length, do not have flat heads and have increments in the shape of palm seeds on upper part.
Al-Jazarî says that he did not give the depiction of each part’s detail of gate, and he left the remaining parts to the manual skill of the artist; while he did not mention that this glass gate was mounted on a solid gate, it is easy to conclude by his prepared nails behind the gate during casting procedures, this was nailed on a solid gate.
Al-Jazarî used a very modern method while casting the closing system. He made a block from candle that has a flat base, emptied the inner side and pipe shape and on the upper side he made some kinds of bubbles to put nails into. Than he covered inside and outside of this block with clay and the candle remained lighted. He adds that the masters of this work know how to do this application. The place of melted candle is filled with glass solution.
In modern casting method, for no movement of block and for homogeneous metal solution, namely for no air bubble, upper side of block is closed with sand and metal solution is poured from a channel into block, the other end is held open for gases to come out. In the casting of the mentioned closing system, it is seen that Jazarî used this method and casting industry had highly developed in this period. Regarding this issue, Lynn White says that: “Particularly the important point is, casting depictions of metals in closed casting tools with green sand were firstly given, that were not used until 15th century in the West”.
Contents of al-Jazari’s book
The book contains six categories:
Category I – Clocks
Category II – Vessels and figures suitable for drinking sessions
Category III – Pitchers, basins and other things (for handwashing and phlebotomy)
Category IV – Fountains and perpetual flutes
Category V – Machines for raising water
Category VI – Miscellaneous
 C. Brockelmann, Geschichte der Arabischen Litteratur, Leiden: Brill, 1943-49, Suppl. I, pp. 902-903; George Sarton, Introduction to the History of Science, Baltimore, 1927, vol II, pp. 632-633.
 See the table of contents of the book below.
 Donald R. Hill, The Book of Knowledge of Ingenious Mechanical Devices (Kitâb fî Ma’rifat al-Hiyal al-Handasiyya) by Ibn al-Razzâz al-Jazzazî, Dordrecht and Boston, 1974; Al-Jazârî, The Book of Knowledge of Ingenious Mechanical Device, Facsimile, Ankara 1990; Al-Jazârî, Al-Câmi Bayna’l-Ilm va’l-Amal an-Nâfi Fî Sinaâti’l-Hiyal, Edited and translated by Sevim Tekeli, Melek Dosay ve Yavuz Unat (in Turkish), TTK, Ankara 2002.
 See Donald Hill, The Book of Ingenious Devices (Kitâb al-Hiyâl) by the Banû (Sons of) Mûsâ bin Shâkir, London, 1979; Atilla Bir, The Book of ?Kitâb al-Hiyal’ of the Banû bin Shâkir, Istanbul, 1990.
 See Lugal, Necati & Sayili, Aydin, Fârâbî’s Article on Vacuum, Ankara, 1951.
 See Carl Brockelmann, Geschihte der Arabischen Litteratur, op. cit., vol I, p. 494; Suppl., I., p. 902; E. Wiedemann, “Hazini”, IA, Cilt 5, Istanbul, 1950, p. 414.
 Figures in this article are taken from the oldest extant copy (preserved in Topkapi Sarayi Libray, Ahmet III collection, MS 3472) was completed by Muhammad ibn Yusuf ibn ‘Uthman al-Haskafi at the end of Sha’ban 602 H/ 10 April 1206. This manuscript is published online at: http://www.ebuliz.com.
*Associate Professor in Ankara University, Turkey, Faculty of Letters, History of Science Department.