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by
Dava Sobel
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January 1 - March 1, 2017
In a single such accident, on October 22, 1707, at the Scilly Isles near the southwestern tip of England, four homebound British warships ran aground and nearly two thousand men lost their lives.
British warship accident that predates the 1714 Longitude Act.
The commissioners charged with awarding the longitude prize—Nevil Maskelyne among them—changed the contest rules whenever they saw fit, so as to favor the chances of astronomers over the likes of Harrison
changing the rules of a challenge prize
relied on “dead reckoning” to gauge their distance east or west of home port. The captain would throw a log overboard and observe how quickly the ship receded from this temporary guidepost. He noted the crude speedometer reading in his ship’s logbook, along with the direction of travel, which he took from the stars or a compass, and the length of time on a particular course, counted with a sandglass or a pocket watch. Factoring in the effects of ocean currents, fickle
crude way of determining longitude prior to Harrison's invention
In 1736, an unknown clockmaker named John Harrison carried a promising possibility on a trial voyage to Lisbon aboard H.M.S. Centurion. The ship’s officers saw firsthand how Harrison’s clock could improve their reckoning. Indeed, they thanked Harrison when his newfangled contraption showed them to be about sixty miles off course on the way home to London.
the first trial for Harrison's clock
Harrison’s house at Red Lion Square. There the inventor, having already completed an improved second version of it, was hard at work on a third with further refinements.
Harrison's iterations
On June 9, 1741, the Centurion dropped anchor at last at Juan Fernandez. The two weeks of zigzag searching for the island had cost Anson an additional eighty lives.
the Centurion tragedy
King Philip III of Spain, who was offering a fat life pension in ducats to “the discoverer of longitude.”
king Phillips prize offering prior to the Longitude Act
Galileo’s technique to redraw the world. And it was in the arena of mapmaking that the ability to determine longitude won its first great victory. Earlier maps had underestimated the distances to other continents and exaggerated the outlines of individual nations. Now global dimensions could be set, with authority, by the celestial spheres. Indeed, King Louis XIV of France, confronted with a revised map of his domain based on accurate longitude measurements,
Galileo competes for the prize
Cassini also called on observers in Poland and Germany to cooperate in an international task force devoted to longitude measurements, as gauged by the motions of Jupiter’s moons.
international crowdsourcing efforts in astronomy
spring of 1714, they got up a petition signed by “Captains of Her Majesty’s Ships, Merchants of London, and Commanders of Merchant-Men.”
the petition that led to the act of 1714
And not likely to be, either, he implied. Perhaps Newton mentioned the watch first so as to set it up as a straw man, before proceeding to the somewhat more promising though still problematic field of astronomical solutions.
Isaac Newton didn't think a solution was likely
On the subject of prize money, it named first-, second-, and third-prize amounts, as follows: £20,000 (the equivalent
first second and third place prizes
The Longitude Act established a blue ribbon panel of judges that became known as the Board of Longitude. This board, which consisted of scientists, naval officers, and government officials, exercised discretion over the distribution of the prize money.
judge's panel
By the time it finally disbanded in 1828, it had disbursed funds in excess of £100,000.)
the total sum distributed over 100+ years
Thus the board received ideas for improving ships’ rudders, for purifying drinking water at sea, and for perfecting special sails to be used in storms.
the competition encouraged ideas beyond those requested in the challenge
To prove worthy of the £20,000 prize, a clock had to find longitude within half a degree. This meant that it could not lose or gain more than three seconds in twenty-four hours.
the advantage of the desired watch was 3 second error when most clocks were off by 15 minutes
John “Longitude” Harrison was born March 24, 1693, in the county of Yorkshire, the eldest of five children.
John Harrison birthday
Harrison completed his first pendulum clock in 1713, before he was twenty years old.
Harrison was self-taught through books. he made his first clock after reading books on mechanics
William, born in 1728, who was to become his father’s champion and right-hand man,
William, Harrison's second son worked on the Longitude project with his father
Longitude posed the great technological challenge of Harrison’s age.
longitude was the greatest technical challenge of Harrison's age
five commissioners— the minimum required by the Longitude Act for a quorum—to bother gathering together for a serious discussion of
5 judge's decided the prize
Graham finally said good night, he waved Harrison back to Barrow with every encouragement, including a generous loan, to be repaid with no great haste and at no interest.
Graham gave Harrison a loan to work on a prototype
Tryal and Improvement, of the sever-all Contrivances,
trial and improvements or iterations, as we call it today
The board gave its stamp of approval to an offer it couldn’t refuse. As for the £500 Harrison wanted as seed money, the board promised to pay half of it as soon as possible.
Harrison receives seed funding from the Board
Board of Longitude, which granted him several extensions on his deadline and five payments of £500 each.
he received several payments over the years
Harrison introduced in H-3 can still be found today inside thermostats and other temperature-control devices. It is called, rather unpoetically, a bi-metallic strip.
a byproduct of Harrison's work on the Longitude project
A bold signature near the plate’s perimeter reads “John Harrison & Son A.D. 1759.”
the winning clock wasn't created until 1759
It purports to be the end of some orderly progression of thought and effort, yet it constitutes a complete non sequitur.
H4 watch proved to be a pivot in Harrison's iterations
Harrison received £1,500, in recognition of the fact that his Watch “tho’ not yet found to be of such great use for discovering the Longitude . . . is nevertheless an invention of considerable utility to the Public.” He could expect another £1,000 when H-4 returned from its second stint at sea.
the Board changed the rules after the watch proved itself.
That autumn, the board offered to hand over half the reward money, on the condition that Harrison hand over to them all the sea clocks, plus a full disclosure of the magnificent clockwork inside H-4. If Harrison expected to receive the full amount of the £20,000 prize, then he would also have to supervise production of not one but two duplicate copies of H-4—as proof that its design and performance could be duplicated.
The Board changes the rules again
Act 5 George III—put caveats and conditions on the original act of 1714, and included stipulations that applied specifically to Harrison. It even named him in the opening language and described the current status of his contrariety with the board.
an official act was put into place to change the rules
Berthoud seemed to expect for peanuts. On behalf of the French government, Berthoud offered
the French government asked for the watch and offered a small prize
Soon another act of Parliament laid out the terms by which the longitude prize could yet be won. This new act of 1774 repealed all the previous legislation on longitude. Its terms for trying new timekeepers threw up the strictest conditions yet: All entries must be submitted in duplicate, then undergo trials consisting of a full
60 years after the act of 1714, challenge prize policy was amended.
Then suddenly, in the wake of Harrison’s success with H-4, legions of watchmakers took up the special calling of marine timekeeping. It became a boom industry in a maritime nation.
the Longitude prize spurred the emergence of an entirely new industry
The secret to Arnold’s speedy manufacture lay in the way he farmed out the bulk of the routine
Arnold began outsourcing to focus on providing value. great business lesson.
Earnshaw who changed the chronometer from a special-order curiosity into an assembly-line item. His own economic need may have inspired him in this pursuit: By sticking to a single basic design (unlike Arnold, who was almost too inventive for his own good), Earnshaw could turn out an Earnshaw chronometer in about two months and then turn the chronometer into ready cash.
Earnshaw the optimizer and Arnold the generator
Arnold and Earnshaw became sworn enemies in a fight over their conflicting originality
friction between two different Basadur types
Thus the total world census of marine timekeepers grew from just one in 1737 to approximately five thousand instruments by 1815.
the growth of chronometers.
