Today, we look at time as a new possession. 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.
The mechanical clock was
really just the millennia-old water clock with new
innards. Looking at an early 14th-century tower
clock, you might not know whether the timing
mechanism was a draining tank of water or a
mechanical escapement mechanism. In either case it
was a half-ton structure that kept time, and
sounded bells, with an accuracy of about plus or
minus fifteen minutes a day.
With its new mechanical innards came the potential
for increased accuracy and reduced weight. But, for
the moment, clocks couldn't be made portable. The
impediment was that the mechanism, and the bells,
were driven by falling weights. Replacing a large
water tank with heavy weights and cables didn't
make clocks any lighter.
To do that, we had to replace the weights with
springs. But as a spring unwinds, it exerts less
force. How to fight that? Some clever inventor
found an answer around 1430. He created a gadget
called a fusee. The mainspring casing is
wound with a string which drives a cone. As the
string unwinds from the cone, its leverage upon the
cone shifts. The string exerts greater and greater
leverage as the spring unwinds, keeping the torque
on the cone's shaft constant.
Now clocks became portable. As the new
spring-driven clocks were mounted in ships and
carriages, the technology of miniaturization picked
up impetus. Author David Landes points out the next
terribly important step. It was making clocks small
enough for one person to carry.
Once we had watches, there followed a great
shift in the very meaning of time. In the years
before the watch, time had become a new master. Our
eyes turned to the clock tower as its bells marked
off the hours. Time turned into a quantity to hoard
as we might hoard gold. The notion of saving time
entered our vocabulary. A decade before the
invention of the fusee, Thomas à Kempis
wrote,
It is sad that you do not employ your time
better, when you may win eternal life hereafter.
The time will come when you will long for one day
or one hour in which to amend; and who knows
whether it will be granted?
That sentiment lingered, but its texture changed as
clocks became personal possessions. Time itself
became a possession. Perhaps it's no coincidence
that the fusee arrived on the eve of the Protestant
Reformation. Clocks had given us the obligation for
saving time. Owning time now meant owning
responsibility for wasting it.
Still, owning time had its up side. Now we could
separate our time from our employer's time. Clocks
made that distinction. The tyranny of time is still
with us, but portable clocks made it a self-imposed
tyranny. Nothing grieves me quite so much as the
person who's so schedule-driven as to have no time
for a friend or for a side road. Nothing is so
delicious as being able to set time aside now and
again and to live only in the moment at hand.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
