Deus Ex Machina: Depicting Cranes and Pulleys in the Ancient World

Within ancient theater, the phrase ‘deus ex machina‘ actually referred to a crane called a μηχανή (the Greek term from whence we get our “machine”) used to suspend and then lower individuals onto the stage during performances of tragic plays, particularly those written by Sophocles and Euripides. In nine of his plays, an epiphanic deus was lowered into the tragedy in order to hasten a resolution. In the Medea, Medea is hoisted and then lowered onto the stage in a chariot that is pulled along by winged (and perhaps bearded) dragons as she carries the two dead boys she shared with Jason in her arms. Pulley systems were used for dramatic and often divine resolutions, but they were also an integral part of building practices in the ancient world.

The development of compound pulleys are a Hellenistic invention attributed to Archimedes of Syracuse in the  late 3rd century BCE for lifting warships. It would be followed by the Roman development of more complex systems developed by the Romans. The use of such cranes and pulleys and how art informs us about their antique use were on my mind as soon as I saw the new 5th century CE mosaic discovered this summer by the UNC Huqoq Excavation Project, directed by Jodi Magness at the Jewish site of Huqoq in Israel (a site I have admired and written about a number of times).

The mosaic depicts the construction of the Tower of Babel (Genesis 11:1-9) in Shinar within Mesopotamia alongside other mosaic depictions of the 12 signs of the zodiac and Jonah being swallowed by a fish. The mosaic is a late antique depiction of the use of pulleys and ropes in order to lift heavy blocks. It appears to use a pulley system and stabilizing beam similar to that described by Vitruvius in Book X of his De Architectura. 

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Jodi Magness and her team have released new photos of their dig at an ancient Jewish village. The fifth century mosaics in Huqoq include a panel depicting the construction of the Tower of Babel, which Magness says gives important evidence of ancient buil pic.twitter.com/wsg65RAbJp

— UNCReligiousStudies (@reliunc) November 28, 2018

Perhaps the most famous depiction of a complex machine used for lifting is that of the treadwheel crane from the Tomb of the Haterii discovered outside of Rome. It contains three Flavian era reliefs, one of which depicts the tomb itself being built in either the late 1st or early 2nd centuries CE. It gives us an idea of the building technology available to Romans at the time of the high empire, but also provides insight into the use of labor to power it. Within the wheel of the crane itself, five small male workers (likely servi) help to power the crane’s system of pulleys, braided ropes, and even the treenails used to hold it together.

We are heavily reliant upon artistic depictions of such cranes since, as Roger Ulrich (2008: 37-38) notes, there are no surviving technical treatises and accompanying drawings that instruct us on their creation of use:

No original copies of Greek or Latin technical treatises have survived; we can only speculate about the kind of graphic aids they may have included. That illustrations once accompanied such literary texts or how-to-do-it handbooks seems a reasonable assumption.

Another Roman relief records the vision of Lucceius Peculiaris as he addresses the genius (“spirit deity”) of the theater itself. The inscription notes that a dream compelled the builder to patronage of a new proscaenium (a theatrical stage component) at Capua (CIL X, 3821): ‘Lucceius Peculiaris redemptor prosceni ex biso fecit‘. Two barely-clothed enslaved workers labor inside of the treadwheel crane to work a system of pulleys. Such reliefs can instruct us not only on the types of machines in use, but also on the types of labor used in a certain period. Just as slaves were used within Roman bakeries to turn the heavy millstones (along with livestock), they appear to have often been assigned work within Roman treadwheels.

Returning back to the mosaic from Huqoq and what exactly the Tower of Babel mosaic can tell us, it is worth noting that medieval manuscripts, frescoes, and mosaics reveal that the construction of the Tower of Babel was a popular theme in art both in the eastern and western portions of the Mediterranean. A 15th century manuscript now at the Getty provides a window into the continued fascination with the tower’s building, but also the anachronism present in such depictions.

A miniature showing the building of the Tower of Babel accompanies Rudolf von Ems’s retelling of the Old Testament story. The dapperly dressed King Nimrod, at left, supervises the construction of the tower by workers. The building procedures probably mirror medieval practices closely. The laborers stand on wooden scaffolding with beams inserted into the walls through put holes. Two rows of put holes are visible below the windows, showing earlier stages of the scaffolding. The workers also hoist bricks and stone to the upper levels using a pulley system.

Art focused on construction practices often projects the building processes of the contemporary moment onto the past. Thus many medieval depictions of the building of the Tower of Babel reflect how a cathedral in the middle ages would have been built. The late 11th century mosaics from Saint Mark’s in Venice (North vault, west side) are a good illustration of this phenomenon (see many more pictures from Dumbarton Oaks’ mosaic library here). Thus we must be careful using any art to reverse engineer machines from differing time periods.

An understanding of ancient technological mechanisms is imperative to understanding the methods and labor involved in the construction of buildings in antiquity––but using art to do so comes with a number of caveats. Artistic depictions provide a starting point, but are no necessarily a blueprint. Late Roman and medieval illustrations of the Tower of Babel’s construction often reveal to us the building processes of the moment rather than those of ancient Mesopotamia. But that doesn’t mean we shouldn’t still look to these works as a means of understanding the personae ex machina who built, operated, and labored within these mechanisms.

Abbreviated Bibliography:

Jean-Pierre Adam, Roman Building: Materials and Techniques, 1st Edition (London and New York: Routledge, 1994).

Seth Bernard, Building Mid-Republican Rome, Labor, Architecture, and the Urban Economy (Oxford: Oxford University Press, 2018).

Christine Sciacca, Building the Medieval World (Los Angeles: Getty Publications, 2010).

Roger Ulrich, “Representations of Technical Processes,” in The Oxford Handbook of Engineering and Technology in the Classical World, edited by John Peter Oleson (Oxford: Oxford University Press, 2008), 35-61.

Andrew Wilson, “Machines in Greek and Roman Technology,” in The Oxford Handbook of Engineering and Technology in the Classical World, edited by John Peter Oleson (Oxford: Oxford University Press, 2008), 337-368.