| Carpenter, self-taught mathematician and the
clockmaker who constructed the first seagoing timepiece, or chronometer,
of sufficient reliability to enable longitude to be calculated at sea,
John Harrison was born at Foulby, in Yorkshire, in the United Kingdom, in
1693.
While employed as an estate carpenter, living in
Barrow-on-Humber in Lincolnshire, between 1713 and 1726, John and his
younger brother James constructed a number of remarkably accurate
long-case clocks, incorporating many unique features.
These features included the first bi-metallic pendulum, to overcome errors
due to temperature variations.
By an act of Parliament in 1714, a Board of Longitude
had been set up to encourage the finding of means of accurate
determination of longitude at sea.
The Board offered a prize of twenty thousand pounds (more than US$33,000)
which was an enormous sum of money, worth the equivalent of between one
and a half to two million pounds in today's terms.
To win the full amount, the invention would have to achieve accuracy to
within 30 miles after the usual six-week voyage to the West Indies.
With his eye on this prize, John Harrison completed four time-keepers
between 1735 and 1760.
The first, a massive mechanism of brass and wood, weighing 72 pounds. The
last, a watch about twice the size of a pocket watch which, in two trials
made in 1762 and 1764, easily fulfilled the requirements to win the award.
Only ten thousand pounds was actually handed over,
however, the remainder being witheld until the Board of Longitude was
satisfied with fresh proof of the general utility at sea of Harrisons'
watch. This ten thousand was scarcely enough to cover the bills amassed
during the almost twenty-five years in which John Harrison had lived from
hand to mouth, abandoning normal employment to concentrate on his
inventions and his last years were embittered by the long struggle to
obtain the remainder of his dues from the Board of Longitude.
It was not until 1773 that these were finally granted by Parliament and
paid to a John Harrison by now blind and eighty years old, living in
near-penury, in spite of his incredible achievement and the promises that
had been made before he handed over his invention.
The behaviour of the Parliament of the day was shameful. Shameful
treatment of a man whose machine had saved fortunes, through time-saving,
and had greatly increased safety at sea, thereby saving lives as well.
John Harrison died only three years after receiving the rest of his prize,
in 1776.
A copy of Harrison's watch, by Lareum Kendall, was used
by Captain Cook on his second voyage of Pacific exploration and gave an
error of less than eight miles in calculated longitude when Cook made his
final landfall at Plymouth Harbour, on the 29th of July 1775, after
circumnavigating the world.
Those four chronometers by Harrison are now preserved in
working order at the National Maritime Museum at Greenwich in London,
England.
Keith Robinson for MarineZine
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