Today, we invent the mechanical clock. The
University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
I've remarked before how hard
it is to date the first mechanical clocks. Old
manuscripts start hinting at them in the late
1200s, but we find no clear picture of a clock
until a century later. One hint was dropped by the
poet Dante in the early 1300s. He said :
As clock, that calleth up the spouse of God
...
Sends out a tinkling sound, of note so sweet,
...
Thus saw I move the glorious wheel; ...
That's no older water clock. Dante had to've been
touched by the rhythmic escapement mechanism and
turning gears of the new mechanical clocks.
Historian Jean Gimpel describes the free-wheeling
medieval view of invention that finally gave us
mechanical clocks:
In a burst of intellectual optimism Gilbert of
Tournay cried, "The truth is open to all, for it is not yet totally possessed."
Bernard of Chartres
said, "We are as dwarfs mounted on the shoulders of giants."
That was six hundred years before Newton
changed it slightly. Bernard was telling us what we
could do. When Newton changed we to
I, it turned from a remark about
possibility into a boast about his own
accomplishments.
Medieval inventors turned their optimism into a sun
spray of creativity: They made Gothic cathedrals,
fully-evolved manuscript books, crossbows,
eyeglasses, water-power systems. And in the
mid-13th century they started thinking about
machines that could point at the moving sun
throughout the day. Not exactly a clock, though
that's what the face of your clock really does
today. In 1271, a writer called Richard the
Englishman issued a tantalizing report:
Clockmakers [he said] are trying to make a wheel
which will make one complete revolution for every
equinoctial circle ... The method of making such a
clock would be this, that a man make a disc of
uniform weight ... Then a lead weight should be
hung from the axis of the wheel, so that it would
complete one revolution from sunrise to
sunrise...
Richard leaves us to wonder how they made a wheel
unwind just one revolution in a day. Was it to be a
very heavy wheel with a very small spindle? Perhaps
the idea had yet to be worked out. Or maybe Richard
had seen one of the new clock escapement mechanisms
and had not fully understood it.
Mechanical clocks were clearly being made by the
early 1300s. Yet not till 1364 did an Italian
clock-maker named Giovanni di Dondi write a proper
treatise on his craft. Giovanni's father Jacopo di
Dondi was a clockmaker who'd built the earliest
tower clock in Padua in 1344.
Lewis Mumford said of the clock that it was
"the key machine of the modern industrial age." He
called the appearance of this first automatic
machine a prophecy that
"marks a perfection towards which other machines aspire." What Dante
had called the glorious wheel was the doorway into
our age of precision machines and high technology.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
Gimpel, J., The Medieval Machine. New York:
Penguin, 1977. (See especially, Chapter 7.)
The passage from Canto X of Dante's Paradiso
goes as follows:
To win her Bridegroom's love at matin's
hour,
Each part of other fitly drawn and urged,
Sends out a tinkling sound, of note so sweet,
Affection springs in well-disposed breast;
Thus saw I move the glorious wheel; thus heard
Voice answering voice, so musical and soft
It can be known but where day endless shines.
For more on the origins of clocks see Episodes
1506, 1307, and 1417.
di Dondi's clock
The Engines of Our Ingenuity is
Copyright © 1988-2000 by John H.
Lienhard.
