Clocks: A Medieval Invention that Changed the Times

FROM THE LECTURE SERIES: THE MEDIEVAL LEGACY

By Carol SymesUniversity of Illinois Urbana-Champaign

The Middle Ages saw a number of inventions that were united by their emergence from a scientific and technological revolution that was taking place in the 13th and 15th centuries. This revolution enabled the conquest of spatial and temporal distance, and was created within a crucible of cultural, economic, and military developments.

Parts of an antique clock
The medieval invention of clocks made it easier to measure the passage of time. (Image: Michelangeloop/Shutterstock)

Measuring Time

The passage of time is something that had theoretically been marked out in hours and minutes, as well as months and years, since the days of the ancient Sumerians of Mesopotamia—but only in the imagination, not in any practical way.

It could be measured, like a stretch of road or a length of cloth, but actually doing so proved difficult and, indeed, unnecessary, until the changing Zeitgeist of the later Middle Ages made its practical measurement newly indispensable.

Dividing the Day in Hours

Since antiquity, societies had usually divided the day into approximate intervals. When medieval sources speak of “the hours of the day”, they are really talking about the two- to three-hour chunks of time that punctuated the work of the day, whether that work was manual labor or the opus Dei, “Work of God”, performed by cloistered religious or pious laypeople turning the leaves of their “Books of Hours”.

But by the end of the 12th century, urban commerce and transnational trade were becoming ever more dependent on exact measures and modes of quantification. To determine the wisdom of taking out a loan, for example, made it desirable to calculate how long one would need to repay the debt.

Fixing the hours of buying and selling, of urban markets and seasonal fairs, was also a more efficient way to do business.

This article comes directly from content in the video series The Medieval LegacyWatch it now, on Wondrium.

Different Types of Clocks

A day divided into approximate hours, perhaps marked by the movement of the sundial’s shadow, is imagined and experienced differently than a day divided into measured and subdivided 60-minute intervals signaled by the ticking and chiming of a city’s mechanical clock.

vintage sundial
The ancient sundials often led to inaccurate measurement of time, making it difficult for the masses to determine the day of the hours with accuracy. (Image: Sanit Fuangnakhon/Shutterstock)

These new, medieval mechanical clocks were much more advanced than the small water clocks, often for domestic use, which had often supplemented sundials since antiquity.

For example, the Tower of the Winds in ancient Athens had been adorned with eight sundials on its octagonal surfaces, to keep time in the polis as Apollo’s chariot moved through the heavens. Although the scientist Archimedes is credited by some ancient sources as having invented a mechanized astronomical clock in the 3rd century BCE, it is not certain whether he actually built it, or merely described its principles.

Advanced Clocks

And there were certainly water-powered astronomical clocks being developed in China around the year 1000.

But the more immediate prototypes for medieval Europe’s public clocktowers were invented by Muslim engineers experimenting with complex systems of gearing in the 11th century.

By the middle of the 13th century, this sophisticated understanding of gears, weights, and pulleys was supplemented by the invention of the escapement, a toothed device which oscillates back and forth, hundreds of thousands of times per day, turning the weighted wheel of the clock at a steady speed and producing the soothing, motivating ticktock that we have come to associate with the passage of time ever since.

Dante’s Depiction of Clocks

The novel sight and sounds of mechanical clockwork is strikingly evoked by the poet Dante Alighieri, who would have been among the first generation of Florentines raised in a city with multiple clock towers. In canto 10 of the Paradiso, Dante describes the joyful, orderly rounds of multitudinous saints revolving together in interlocking processional circles, like a divinely wound mechanical clock:

Then, as a chiming clock that calls us
at the hour when the Bride of God arises
to sing a Matins to Her Love, Her Spouse—
one pulling, one part pushing those devices
that sound ting ting with such sweet music notes
that swell the loving spirit as it rises—
so did I see that wheel’s most glorious rotes
turn interlocking voices, keeping time
in sweetest harmony with others’ notes
which only those in joy eternal rhyme.

Dante’s onomatopoeia charmingly captures the silver sound of the chimes “that sound ting ting with such sweet music notes” (tin tin sonando con sì dolce nota) while his imagined wheels of marching saints evokes the smooth revolutions of moving gears.

Scholars on Clocks

The earliest visual depiction of the tower for such a clock is preserved in the notebooks of the 13th century architect and draughtsman Villard de Honnecourt, who details the dimensions of its four “stages” or storeys. A later, much less sophisticated hand has added the label, “This is the house of a clock”, (Cest li masons don horloge).

Giovanni Tortelli, one of the first humanist scholars to master the study of ancient Greek and a major intellectual architect of the Vatican Library, praised the public clock tower for its accuracy, utility, and sensory properties.

Not only does it display and mark the hour to our eyes, but its bell announces the hour to the ears of those far away or remaining at home. Hence, it appears to be alive, in a way, because it moves of its own volition and does its work on behalf of mankind, night and day.

Or, as the French satirist François Rabelais put it, rather more crudely: “A city without clocktower bells is like a blind man without a stick, an ass without a crupper, or a cow without a cowbell.”

Like hospitals and prisons, then, clocks were becoming a source and mark of civic pride—and also, at times of strife, sites of urban resistance to external checks on civil liberties.

Common Questions about the Medieval Invention of Clock

Q: What is escapement?

Escapement is a toothed device which oscillates back and forth, hundreds of thousands of times per day, turning the weighted wheel of the clock at a steady speed and producing the soothing, motivating ticktock that we have come to associate with the passage of time ever since.

Q: How does Dante use the imagery of clock in his Paradiso?

In canto 10 of the Paradiso, Dante describes the joyful, orderly rounds of multitudinous saints revolving together in interlocking processional circles, like a divinely wound mechanical clock.

Q: How were clock towers visually depicted by scholars of the time?

The earliest visual depiction of a clock tower s preserved in the notebooks of the 13th century architect and draughtsman Villard de Honnecourt, who details the dimensions of its four “stages” or storeys.

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