Today, we spend a lifetime making a 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.
John Harrison was born in
Yorkshire in 1693. When he came down with smallpox
at the age of six, his parents put a watch on his
pillow to keep him company. 17th-century watches
were large and not very accurate, but you could see
their works and relate the loud ticking to
mechanical action. That odd monosyllabic companion
awakened young John's imagination.
Navigation came a long way between Columbus's
voyage and John's birth. But calculating a ship's
precise longitude was still a nasty problem. It was
easy enough if you knew Greenwich Meridian time (or
Greenwich noontime) at the local noontime. The
trouble was, no clock held its accuracy well enough
during months at sea.
Harrison was 21 and just starting in the trade of
clockmaking, when Parliament offered a prize of
20,000 pounds. To win it you had to invent a clock
that could hold a ship within half a degree of
longitude on a trip all the way to the West Indies.
20,000 pounds was an enormous sum, because in 1714
the challenge looked impossible.
Harrison decided to win the prize. He invented a
new escapement mechanism and a bimetallic
temperature compensator. In 1728 he went to London
and found financial backing to make a seagoing
model. On a test voyage in 1735 he navigated from
Lisbon to London within 1½ degrees -- very
impressive but not enough to win the prize.
When Harrison finished a second clock, England --
now at war with Spain -- wouldn't let him test it
at sea for fear the Spanish might capture it. So he
went on improving. His third clock was a fine
instrument, but he saw how to make it still better.
He built a fourth clock -- a beautiful little
four-inch-diameter masterpiece with jeweled action.
He was now 68 and had, in his words, put into it:
... fifty years of self-denial, unremitting
toil, and ceaseless concentration.
He went on to say,
I think I may make bold to say that there is
neither any other Mechanism or Mathematical thing
in the World that is more beautiful or curious in
texture than this my [longitude] Time-keeper.
Harrison was too old for another voyage,
so he sent his son off to the West Indies in 1761.
The clock lost 5 seconds on the trip and placed them
within 1-1/4 minutes of longitude at Jamaica.
Now the Royal Society began to waffle. They gave
him 2,500 pounds of prize money, but the rest
depended on a second trial. When the clock did even
better, they gave him 7,500 pounds more and
withheld the other 10,000 pounds until he could
deliver two more time-pieces. Finally, after the
aging Harrison produced a fifth, even more
accurate, clock, King George stepped in and told
the Royal Society to give in. Harrison had finally
won the prize at the age of 80.
Harrison had devoted his entire life to adding one
really beautiful and lasting thing to this world.
It was a hard bargain, but in the end it was a
bargain we all might envy.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds