Dava Sobel's Longitude achieved bestselling status on the New York
Times nonfiction list in both hardcover and paperback. That it has
done so speaks well for the reading public in this country.
Part biography, part history, part scientific exploration, Longitude
relates the quest for an accurate way to determine longitude. Unlike
parallels of latitude, which are fixed by nature, longitude is judged
by means of time. Specifically, you must know the time where you are
and the time at a known longitude simultaneously. The longitude
problem remained unsolved for the better part of human history; it was
a matter of life and death to those on ships at sea. If you didn't
know your longitude, you couldn't know exactly where you were, and land
could rise out of the water with terrible suddenness, smashing your
ship and those it carried against land's end.
When the British Parliament in the Longitude Act of 1707 named a prize
equal to several million of today's dollars for a "Practicable and
Useful" means for determining longitude, the race to find the answer
was on in earnest. There were two schools of thought on the longitude
problem. The scientific school maintained that the solution lay in
mapping the heavens. Most scientists of the day disdained those who
followed the other path of enquiry, those who believed that necessity
required the construction of a precision timekeeper. John Harrison,
an English clockmaker, devoted his life to that quest.
Sobel tracks Harrison's progress in the race for longitude, and all the
travails and mistreatment he experienced down that road. Little is
actually known of Harrison's life, but much of the bitter rivalry
between the astronomers and the "mechanics" is detailed in written
records. It is the struggle between these two factions that makes
for Longitude's compelling reading.
Sobel writes with clarity and vitality, including interesting little
historical asides that help ground the reader in the story's era. Her
style at times simply enchants. My favorite line in the book occurs when
Sobel describes John Harrison's utter inability to present an idea
in writing despite his genius in other arenas. She writes:
Summarizing the essence of his conversion chart in a
handwritten heading, Harrison called it "A Table of the
Sun rising and Setting in the Latitude of Barrow
53 degrees 18 Minutes; also of difference that should
& will be betwixt ye Longpendillom & ye Sun if ye
Clock go true." This description owes its quaint
sound partly to its antiquity, and partly to ambiguity.
Harrison, according to those who admired him most,
never could express himself clearly in writing.
He wrote with the scrivener's equivalent of marbles
in his mouth.
With obvious sympathy for this man whose lifework would solve the
problem of longitude, and with evident passion for the subject,
Dava Sobel has created a small treasure in writing this book. When
she writes another, you'd do well to pick it up. In the meantime,