Additional boxes with combination locks


One of the best pleasures of maintaining such a blog is the emails I receive occasionally that expose me to information I am not familiar with. This time on three boxes with combination locks quite similar to the combination lock designed by al-Jazari:

The box from the Khalili Collection (ناصر خليلي)

The box from the Basilica of St. Servius in Maastricht (Netherlands)

Al Baghdadi’s box (البغدادي)

The Box from the Khalili Collection

Bernard Gallagher drew my attention to the connection he found between Leonardo da Vinci’s famous Annunciation painting and al-Jazari’s machines:

To the best of my knowledge, there is no translation of al-Jazari into Latin. I am not familiar with al-Jazari knowledge in the West before the groundbreaking work of Eilhard Wiedemann and Fritz Hauser in 1915. It is impossible, of course, to know whether an Arabic manuscript ended in Leonardo’s hands. You can read for yourself Bernard Gallagher and be convinced (or not). But during my search due to  Bernard’s ideas, I discovered this box in the Khalili collection:

Sir Nasser David Khalili (ناصر داوود خل یلی) is a British-Iranian scholar, collector, and philanthropist who, starting in 1970, has built one of the richest private art collections in the world, documented in 36 volumes that can be seen here and includes ancient manuscripts from the 4th century BC in Aramaic from Bactariya, present-day eastern Afghanistan, to Japanese artifacts from the 19th century. An important part of the collection is Islamic artifacts, including the box, between 700-2000. In volume 12, “Science, Tools & Magic Part Two: Mundane Worlds” I found information about the casket. Unlike the boxes from Isfahan (which appear in the original post), this box is neither signed nor dated. It is cast in brass and inlaid with silver. Based on the metalwork, it can be assumed that the casket was made in Jazira between the mid-13th and 14th centuries. Like al-Jazari’s box, it has four dials with 16 letters, and the correct choice of letters allows the lid to be opened. As with al-Jazri, the 16 letters used do not need diacritic marks, such as ب (ba) or ن (nun), with only the dot’s position distinguishing between the letters. The locking mechanism is simpler than al-Jazari’s (true for all three boxes) and includes only four letters compared to al-Jazari’s chest, where twelve letters are required (Detailed explanation in the original post). There are no photographs of the mechanism in the book, and if I will obtain them in the future, I will be happy to make a more detailed comparison.

Al-Baghdadi’s (البغدادي) Box from Mosul

The Khalili Collection book mentions the two boxes from Isfahan and an anonymous box from New York. I couldn’t find the box from New York, but during my search, I found this box from Mosul, which was sold at Christie’s auction house in 2010:

It is a brass box with silver inlays mostly removed with a scalpel; the silver remained only in the lock area and in places that were difficult to remove. In addition to the geometric decorations, there are hunting scenes, a figure on a camel, and much more. On the box, there is an inscription. This is the only photograph I have found, but if I understand correctly, there are two types of inscription on the box: one in the letter Naskh (خط ألنسخ ), a small round script in Arabic calligraphy. The second is Kufic (خط كوفي), the oldest calligraphic form of the Arabic script. The text includes proverbs such as الماجد والملك, meaning splendor and rule, as well as the name of the artist who made the box, Mohammed al-Baghdadi.

This box also has a similar but simple version of the lock of al-Jazari, with four dials placed at the four corners of the lid. When the combination of dials includes the correct four letters, you can lift the cover by turning the handle in the center. If I understood correctly, the mechanism was preserved in this box, but the letters that were apparently engraved on the silver inlay are missing.

The Box in the Basilica of St. Servius

Almost the same week, Danielle Arvanitis wrote to me about an ivory box she saw in the Basilica of Saint Servatius in Maastricht (Netherlands):

According to the legend, Saint Servatius, a distant relative of Jesus, was an Armenian from the 4th century AD who arrived in the city of Maastricht and became the first bishop of the Netherlands. There is evidence of pilgrimages to the basilica as early as the 6th century AD, and historical figures such as Charlemagne, Henry II, and others made pilgrimages to the saint’s remains found in a magnificent coffin belonging to the basilica’s treasury. In addition to the remains, the treasure has unique artifacts, including a spectacular collection of ancient silk fabrics, ostrich eggs, and this box.

I have found no scientific papers discussing the box other than a 1985 article by J. Klamt in German, whose charming title “Elfenbeintasten mit Kombinationsschloss” means “combination locks and ivory keys.” According to the picture’s caption, the box’s origin is in Sicily from the 13th century. I am grateful for all the information I can find on the WEB. Still, materials that do not undergo scientific review are questionable, so this may be inaccurate.

The Emirate of Sicily was a Muslim kingdom with Palermo as its capital from 831 to 1091 AD. In 826, a Byzantine general named Euphemius defected, allied with the Aghlabids ruler (Arabic: أغالبة, a dynasty of Muslim emirs who ruled over a North African kingdom), and transferred to the Muslim navy the technique of “Greek fire,” a very dangerous incendiary weapon used by the Byzantine to set enemy ships on fire, This story warrants a separate post because the process of preparing Greek fire was kept very secret,  And to this day we do not know for sure what its components were.

Either way, under Muslim rule, Sicily became a trade center in the Mediterranean and had large and prosperous Muslim, Christian, and Jewish communities. Later, Sicily fell to the Normans (tribes of Viking origin). The destruction of Islam in Sicily was completed by the late 1240s, accompanied by pogroms against the Muslim and Jewish populations. If the box is from Sicily, it is probably before 1240, close to al-Jazari’s time.


The combination locks make us think of a safe, but these boxes (all three mentioned and al-Jazari’s original) are not safes at all, and the ivory box emphasizes this. There were skilled blacksmiths in the 12th century with very high capabilities in steel, and the fact that the boxes were built of brass or, even worse, ivory means that they were not designed to protect valuable property from burglary. Both al-Kindi (الكندي) and al-Biruni (البيروني) write in the 9th and 10th centuries about steel and forging and specifically about Damascus steel (فولاذ دمشقي), which is a carbon-rich steel that has undergone special processing. Despite its name, Damascus steel originated not in the city of Damascus, but in the region of India, from where it passed to Arab countries. The Europeans, who arrived in the Middle East during the Crusades, brought the swords to Europe. The choice of ivory or brass indicates that these boxes were safely housed in a protected place, like that of the Arthuqid ruler in Diyarbakır. They may have contained documents intended only for the eyes of the ruler and his close advisers, or they may have been beautifully designed with high engineering and aesthetic capabilities.

Al-Jazari Combination Lock and the Boxes from Isfahan

“This Ifrit bore me off on my bride night, and put me into a casket and set the casket in a coffer, and to the coffer he affixed seven strong padlocks of steel and deposited me on the deep bottom of the sea that raves…and this wretched Jinni wotteth not [does not know] that destiny may not be averted nor hindered. ”

The Story of King Shahryar and His Brother from The Arabian Nights, translator Sir Richard Burton,1850.


In Category six that consists of “dissimilar designs” al-Jazari describes “A lock for locking a chest using 12 letters of the alphabet”.

Locking board in the alphabet lock, Topkapi manuscript, 1206

Description of the Chest by al-Jazari

The technical explanation, as always, will be colored in blue, so anyone who is not interested in cylinders or cotter-tapered pins can skip those bits. This is a chest with four combination locks in the four corners of the cover. Each combination lock uses sixteen out of twenty-eight letters in the Arabic alphabet; it uses the letters without a diacritical mark, a point, or sign added to a letter to distinguish it from another similar letter. For example, the difference between bāʾ ب (comparable to b in English) and nun ن (comparable to n in English) is the location of the point below or above the letters. Al-Jazari doesn’t explain his choice, perhaps to prevent mistakes.

The four dials

Chest reconstruction from HTTP://WWW.JAZARIMACHINES.COM/EN (link is not working anymore)


The four dials on the chest cover are relatively complex. Each dial consists of three disks with a triangular notch in its outer perimeter. When all the notches were aligned, the chest could be opened. I attached the original drawing of al-Jazari cross-section of the dial with the modern drawing of Hill and added captions:

Integrated drawing of the lock components, the original drawing by al-Jazari, with the modern drawing by the book translator and annotator, Dr. Donald Hill

Since it still seems complicated to comprehend, I added the drawing of the components before assembly:

The dial component, a drawing by the book translator Donald Hill, with my captions

When you turn each of the three cylinders to their proper letter, all notches are aligned and allow the opening of the lock. It requires the knowledge of twelve letters, three letters per each dial multiplied by four dials. This system is held in place together but allows convenient rotation of its components using a cotter-pin. When you want to change the code, you remove the pin and mechanically rotate the disc so the location of the notch will match the chosen letter.

The Isfahan Boxes

None of the wonderful machines of al-Jazari survived the hundreds of years passed, and all we have are beautiful manuscripts. I fantasize about an extensive archaeological excavation in the Palace in Diyarbakir that would reveal remnants of the castle’s clock or any other monumental work. Until then, both boxes with alphabet locks from Isfahan in Iran dated to the late twelfth century are the closest thing to time travel, to see al-Jazari at his work. In the David Museum in Copenhagen, there is a fragmented brass box inlaid with silver and copper with four alphabet locks. The four dials are in a straight line and not in the four corners of a rectangle, but the similarity to al-Jazari’s chest is evident. Like al-Jazari each dial contains 16 letters. The letters which are used are without a diacritical mark. There is a resemblance to the locking process and the details of the mechanism. The box is simpler, and each dial has just two cylinders. Only eight letters (and not twelve) are required to open the crate. On the box there is the maker signature saying:

“Work of Mohammed b. [Ben] Hamid al Asturlabi

 Al Isfhani in the year

Five hundred and ninety-seven [1200 AD]

And I have tested it[it works]”

Fragments of a box made by Asturlabi, 1200 AD, Museum David Copenhagen

To my astonishment there in another safe from the same period by Asturlabi at the Boston art museum. This box also has four alphabet locks of two cylinders, creating eight-letter code. This time also there is an additional three guards’ façade, probably as symbolic protection from a later period. The signature indicates that the box was prepared by Asturlabi four years earlier (593 to AH or 1197 AD). Although it’s childish, I can’t help feeling a bit left out: why two boxes by Asturlabi from Isfahan have survived and not even one machine by al-Jazari? There is no answer, nor there can be one.

Box by Asturlabi,1197 AD, Isfahan, Boston Arts Museum


From the name of the maker, it is obvious that his profession and probably the family profession was producing astrolabes. Astrolabe (ٱلأَسْطُرلاب) is a sophisticated device of astronomers and navigators to measure the angle of a star above the horizon. It has many functions but was used primarily for finding latitude when you know the local time or as a clock when you know your position. There is a good explanation and a demo here. Four astrolabes from the 12th century created by Asturlabi family from Isfahan still exist, but I could not find their pictures. There are pictures of astrolabes from Isfahan from the 9th century until the 16th century, and this is one beautiful example:

The 13th-century astrolabe from Isfahan, Muhammad B.AbiBaker, The Museum of the history of science, Oxford.

Surprisingly, perhaps, there is a link between the astrolabe and the combination locks. The lock consists of rotating cylinders with respect to the alphabet circle. In the astrolabe, there is a framework called “Rete” bearing a projection of the ecliptic plane and several pointers indicating the positions of the brightest stars. This frame is free to rotate in respect to the astrolabe disk, called the mater (mother). Both the astrolabe and the alphabet lock are rotating mechanical systems around the center. This is done in both cases by using a cotter pin (a tapered pin) that holds all the components in place and allows rotation around an axis. This pin has the shape of a horse head, hence his name in Arabic فرس (mare). I attach a photo of astrolabe dismantled; you can see exactly the same mechanism and the same cotter pin (red circle) as in the drawing by al-Jazari above.

Astrolabe dismantled for parts. The cotter pin in the red circle

If you really want to go on a historic-scientific journey, you can read the guide that Geoffrey Chaucer wrote for his 10-year-old son Lewis. Chaucer, one of the fathers of the English literature and the author of “The Canterbury Tales” was also an astronomer. This is the first publication in English on this topic as well as a great introduction to the Astronomy in the 14th century. The guide contains more than fourty (!) uses the astrolabe.

Who’s ahead?

Al-Jazari wrote  in the opening paragraph:

“The earlier [workers] in this craft made locks for locking and opening by means of the letters. Among them were [those that] locked by means of  four  a chest and made a lock on its lid as I shall describe”

Al-Jazari, obviously, did not claim primacy. Is it possible that the Isfahan boxes are part of the boxes that al-Jasari mentioned? Could it be that al-Jazari book got to Isfahan and inspired Asturlabi to build his boxes? The answer is probably no to both. The boxes were made in the years 1197-1200. We don’t have an exact date for completion of the book.  Rachel Ward claims that the book was written between 1200 to 1197. It’s a little earlier than Donald Hill who believed that the book was written between 1204-1206. The small gap is due to different sources. Hill was relying mainly on the copy from Oxford University, and Ward is basing her calculation on the earlier copy of Topkapi. Either way, the closeness between the time the book was written and the dates of the production of the boxes in Isfahan almost negates the possibility of mutual influence. Much more likely is both the Isfahan boxes and al-Jazari’s chest are part of the same rich material culture in the Muslim world at the time.

It is interesting to note that the first alphabet lock in Europe is probably the work of Giovanni Fontana, A Venetian engineer from the 15th century, three hundred years after al-Jazari. Fontana was very diverse, including measuring heights with falling stones, water and sand clocks, and trigonometric measurements. He wrote one of the first technology books in the Renaissance: “Bellicorum Instrumentorum Liber.” The book includes siege machines but also fantastic inventions like a bird propelled by a rocket, and an early version of four wheels bicycles and last but not least an alphabet lock:

The alphabet lock of Giovanni Fontana, 1420-1430