208 pages, Walker & Company, ISBN-13:
978-0802715296
In
the early 18th Century, one of greatest scientific problems face by learned men was
calculating longitude (that would be the geographic coordinate that specifies the east–west position on the surface of the Earth) on the high seas. At the time, navigators had two
choices, both treacherous: they either traveled well-known routes, thus opening
them to the threat of pirate attacks; or they used imprecise navigational
methods to avoid that danger. But the latter method presented its own problems,
as it was more deadly because ships often got lost at sea or ran aground. Many
sailors lost their lives and vast fortunes were dashed as ships crashed into
rocks. The problem was so serious that the English Parliament passed the
Longitude Act in 1714, establishing a panel of judges to study the
problem and announced a prize of £20,000 (worth millions of dollars today) to
anyone who could determine longitude accurately.
Enter
John Harrison, a self-educated amateur clockmaker from Yorkshire, who believed
that the solution lay in time, not in the heavens, as the scientific
establishment had long postulated. Harrison devoted his entire life to the pursuit
of the longitude prize, all the while battling university scholars who thought
him an incompetent crank. In
Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time, author Dava Sobel tells
Harrison's story with vigor and insight. It is clear that she greatly admires
Harrison's genius and determination, and she describes how he “went from…humble
beginnings to riches by virtue of his own inventiveness and diligence, in the
manner of Thomas Edison or Benjamin Franklin”.
Throughout
Harrison's illustrious career, he invented a number of innovative techniques
for keeping accurate time-and solved many problems that had plagued clockmakers
for centuries. Sobel writes: “Most pendulums of Harrison's day expanded with
heat, so they grew longer and ticked out time more slowly in hot weather. When
cold made them contract, they speeded up the seconds, and threw the clock's
rate off in the opposite direction”. Harrison solved this by “combining long
and short strips of two different metals – brass and steel – in one pendulum…” Another
invention of Harrison's was caged ball bearings, which are still used today.
Harrison
did eventually win the longitude prize, but not until he was in his late 70s.
The debate over the way longitude would be found raged on throughout his many
trials over the decades between the 1720s and the 1770s. He submitted two
clocks to the Longitude Board between 1737 and 1741 (named H1 and H2), but
spent nearly twenty years perfecting H3, which he finally submitted in 1769.
During this time, a rival 40 years younger than Harrison, the Reverend Neville
Maskelyne, insisted that the lunar distance method was the way that longitude
was to be found. Sobel makes clear that Maskelyne, while a foe to Harrison, was
not exactly a villain; he was rather more like an anti-hero. While Harrison's
method eventually won out, Maskelyne did make many important contributions to
the science of astronomy. Sobel is objective enough to give credit where credit
is due.
Longitude
is written in a breezy, easy-to-read style. Sobel tells her tale
chronologically, providing the essentials of the struggle while maintaining the
historical context. She describes the painstaking observations and integrations
that Harrison had to make in order to create his famous clocks. The solitary
years he spent in his workshop focusing on his central goal is an inspiration
to behold, particularly in an age like ours, where the individual is often
looked upon with derision and contempt. Because
Longitude is a popular account, there are few technical details, but for the most
part this lack of detail does not detract from the book, but occasionally the
lack of technical description confuses the reader (for example, Sobel never explains how one determines local time on a moving ship). Nevertheless, this flaw
does not detract from the overall value of the book. Sobel tells her tale well
and brims with enthusiasm for John Harrison and his wonderful invention that
solved a centuries-long obstacle to safe navigation on the high seas. At the
end of the book, Sobel touchingly describes her reaction to seeing Harrison's
clocks for the first time: “Coming face-to-face with these machines at
last-after having read countless accounts of their construction and trial,
after having seen every detail of their insides and outsides in still and moving
pictures-reduced me to tears”. Spoken like a true history geek.
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