The third raising water machine described by al-Jazari is clearly an attraction in the King Palace and not a solution to irrigation problems in Diyarbakir. It’s not just the fake cow(!) made of wood, and I will elaborate on this later on, but the text speaks for itself:
“[The one described here] is beautiful to behold, with upper wheels, splendid craftsmanship, elegant shapes, and handsome design. The ropes are silken, the jars delicate and painted with various colors, as are the wheels, the cow and the disc.”
In this respect, he reinforces the concept of the palace Engineer as a “magician.” I wrote about this briefly here [in Hebrew], and I will use the third pump to expand. This design is based on the saqiya (Arabic ساقية), an ancient device for raising water that can still be seen today. In the following paragraphs, I will explain the saqiya and the similarities and differences from al-Jazari’s pump.
How does it work?
The technical explanation, as always, will be colored in blue, so anyone who is not interested in Scoop wheel or Sindi wheel can skip those bits
Al-Jazari device is relatively complex, and only the top part is visible to the observer. This is the original drawing by al-Jazari with my captions:
The center of the device is a square pool with a bottom copper plate, and its sides made of marble. The water flows into the pool and down through an opening on a scoop wheel which is hidden in a chamber below the pool, not visible to the observer. The scoop wheel rotates toothed wheels that transmit the movement to a vertical axle. The axle is hidden within a copper pillar with a copper disc. A wooden cow is standing hairsbreadth above the disk, light as possible and supported by a wooden rod attached to the axle. In this way, it looks like the cow is operating the traditional saqiya. (Pictures and explanations of the saqiya will follow).Toothed wheels turn the Sindi wheel which has the jars on it. Thus raising the water and dispenses the water into the irrigation system of the Palace’s garden (not in the drawing).
It is interesting to note that al-Jazari calls the wheel of the Saqiya “Sindi wheel,” Sindh is in the western corner of South Asia, bordering the Iranian plateau in the west, today in Pakistan. So at least in his time, it was assumed that this is the “origin” of the saqiya.
This was the most effective device for raising water used from Spain in the West to India in the East at least from Roman times to the insertion of motorized pumps. An animal (Ox or a donkey) turns a horizontal wheel, which is engaged with the vertical wheel and so causes it to turn. This causes the belt of buckets or jars to circulate and lift water from the well or the stream. There is no knowledge about the origin of the device. Some claim it was ancient Egypt, 4th century BC, some claim Persia and al-Jazari, and his contemporaries thought Sindh. Regardless of the history, it was very common throughout the Muslim world during the middle ages.
There are many testimonies to the early saqiya here in Israel. The most ancient one in Tel Dor. A saqiya also appears in “The Picturesque Palestine” published in the early 1880s by Charles William Wilson:
The Saqiya is five times more efficient than the Shaduf, which was explained here. It can pump 10-25 cubic meters of water per hour. The unusual version of al-Jazari did not use animal power but water energy. The use of water power for pumping and industrial use, for instance, in the paper industry was known at the time of al-Jazari. The most common device was Noria(ناعورة), which consists of a large water wheel of wooden containers, as shown in the photograph below:
Al-Jazari did not use the noria but the scoop wheel, I may write on this choice in the future. I am more intrigued by the wooden cow.
Why a wooden cow? Or the engineer as a Magician
The wooden cow of al-Jazari contradicts all engineering logic. First of all, it has no contribution to the water raising secondly it loads the pump and reduces its efficiency. Funny that Wikipedia writer wrote:
“A manuscript by Ismail al-Jazari featured an intricate device based on a saqiya, powered in part by the pull of an ox walking on the roof of an upper-level reservoir, but also by water falling onto the spoon-shaped pallets of a water wheel placed in a lower-level reservoir.
An observer in the 12th century would not make this mistake. The dimensions of the wooden cow are not specified, but the copper disc is about two spans or ~ a half meter. The central axle that connects all the toothed wheels is 12 spans or approximately 3 meters. Even if the image isn’t to scale, it is obvious that the cow was a decoration and was not intended to mislead the observer. Why al-Jazari did this?
My love, M. thinks it is the handicap principle. The handicap principle is a hypothesis originally proposed in 1975 by Israeli biologist Amotz Zahavi with his wife Avishag Zahavi to explain strange phenomena in nature. Their book is called “peacocks, altruism, and handicap principle” (in Hebrew). The amazing colorful peacock’s tail requires physiological resources to build and maintain, attracts the attention of predators, and hinders the peacock’s ability to escape. At the same time the heavy tail signal peahens that the peacock is very sure of himself and has an impressive set of genes, thus improving his chance to find a spouse. In some paradoxical way, the colorful tail of the Peacock also manages to deter potential predators. In the 1970s, there was broad opposition to the handicap principle because it contradicts the principles of evolution, but today it is widely accepted. Did al-Jazari want to show that an unneeded wooden cow doesn’t bother him to raise water with joy?
I prefer another explanation. We perceive engineers as professionals who analyze data to design and build machines, structures, or materials to achieve the objectives, taking into account the product requirements and limitations, including regulations, cost, safety and more. Al-Jazari was working in a different environment with far fewer limitations and no regulation at all, but his concept of engineering and his role were different. Engineers are hiding mechanisms for any number of reasons, but why Al-Jazari chose to hide the mechanism? Did the tiny wooden cow stress the lack of the usual animal in the saqiya?
I suggest that in al-Jazari’s perception, the engineer is a little bit a magician. It is certainly true for the Magic Pitcher or some of the automata, and it is true for this pump. The hidden mechanism and wooden cow are used to make the riddle more intriguing. It makes no sense to ask a magician about the efficiency of his act, and likewise, there is no sense to ask Al-Jazari why a cow? His goal was not an effective pump, but the wonder of the beholders. Elly Truitt wrote an interesting book called “Medieval Robots” about the transition of Western Europe between the perception of automata as magical to science and technology approach. Truitt tells of a 12th-century book “Chansons de geste, le Voyage de Charlemagne” (Songs of Deeds, the travels of Charles the Great”). The story is about the visit of Charlemagne to King Hugo’s court in Constantinople. Charlemagne and his barons were astonished by an automaton of a rotating palace mimic the circular motion of the celestial sphere. When the west wind blew the Palace turn, and two copper children blew their ivory horns with heavenly music. Charles’s court thought that this automaton was so expressive that they would have believed they were actually alive. Charles and his barons were unfamiliar with the technology, lost their footing once the palace began to turn. This story is fictional. Charlemagne didn’t make this expedition to Jerusalem and didn’t stop in Constantinople on his way. It is true that there were remarkable automata in the courtyard of Byzantium in the 9th century and a people from the west who had no technological know-how, thought that magic and sorcery are involved. Al-Jazari is the magician but with no magic but hidden scoop wheel and clever use of toothed wheels.