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by
Dava Sobel
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June 28 - July 9, 2024
who commanded expensive materials and experienced machinists in the clock centers of cosmopolitan London.
When John Harrison arrived in London in the summer of 1730, the Board of Longitude was nowhere to be found. Although that august body had been in existence for more than fifteen years, it occupied no official headquarters. In fact, it had never met.
Harrison, however, knew the identity of one of the most famous members of the Board of Longitude—the great Dr. Edmond Halley—and he headed straight for the Royal Observatory at Greenwich to find him.
Well liked by most, kind to his inferiors, Halley ran the observatory with a sense of humor. He added immeasurably to the luster of the place with his observations of the moon and his discovery of the proper motion of the stars—even if it’s true what they say about the night he and Peter the Great cavorted like a couple of schoolboys and took turns pushing each other through hedges in a wheelbarrow.
Graham, who was about twenty years older than Harrison, became his patron at the end of one long day together. As Harrison described their first meeting in his inimitable prose, “Mr Graham began as I thought very roughly with me, and the which had like to have occasioned me to become rough too; but however we got the ice broke . . . and indeed he became as at last vastly surprised at the thoughts or methods I had taken.”
When 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.
Proctor needn’t have worried about the performance of Harrison’s machine. It was the man’s stomach that gave him grief. The rough crossing kept the clockmaker hanging over the rail much of the time, when he wasn’t in the captain’s cabin, tending his timekeeper.
When the ship neared land at last, Wills assumed it to be the Start, a well-known point on the south coast around Dartmouth. That was where his reckoning placed the ship. Harrison, however, going by his sea clock, countered that the land sighted must be the Lizard on the Penzance peninsula, more than sixty miles west of the Start. And so it was. This correction greatly impressed Master Wills. Later, he swore out an affidavit admitting his own mistake and praising the accuracy of the timekeeper.
But it wasn’t good enough for Harrison. The same vicelike conviction that led him to his finest innovations—along his own lines of thinking, without regard for the opinions of others—rendered him deaf to praise. What did it matter what the Royal Society thought of H-2, if its mechanism did not pass muster with him? Harrison, now a London resident and forty-eight years old, faded into his workshop and was hardly heard from during the nearly twenty years he devoted to the completion of H-3, which he called his “curious third machine.” He emerged only to request and collect from the board
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In longitude determination, a realm of endeavor where nothing had worked for centuries, suddenly two rival approaches of apparently equal merit ran neck and neck. Perfection of the two methods blazed parallel trails of development down the decades from the 1730s to the 1760s. Harrison, ever the loner, pursued his own quiet course through a maze of clockwork machinery, while his opponents, the professors of astronomy and mathematics, promised the moon to merchants, mariners, and Parliament.
John Flamsteed alone personally donated some forty man-years to the monumental effort of mapping the heavens. As the first astronomer royal, Flamsteed conducted 30,000 individual observations, all dutifully recorded and confirmed with telescopes he built himself or bought at his own expense. Flamsteed’s finished star catalog tripled the number of entries in the sky atlas Tycho Brahe had compiled at Uraniborg in Denmark, and improved the precision of the census by several orders of magnitude. Limited as he was to the skies
Halley concluded from these sources that the moon’s rate of revolution about the Earth was accelerating over time. (Today, scientists assert that the moon is not speeding up; rather, the Earth’s rotation is slowing down, braked by tidal friction, but Halley was correct in noting a relative change.)
Once ensconced at Greenwich, Astronomer Royal Bradley, like Flamsteed and Halley before him, took the perfection of navigation as his primary mission. He out-Flamsteeded Flamsteed with his precision maps of the heavens—and his modest refusal of a raise in pay when it was offered to him.
Even the difficulty of taking lunar distances, or lunars, as they came to be called, augmented their respectability. In addition to the need for measuring the altitudes of the various heavenly bodies and the angular distances between them, a navigator had to factor in the objects’ nearness to the horizon, where the steep refraction of light would put their apparent positions considerably above their actual positions.
Worse, this device of Harrison’s had all the complexity of the longitude problem already hardwired into its works. The user didn’t have to master math or astronomy or gain experience to make it go. Something unseemly attended the sea clock, in the eyes of scientists and celestial navigators. Something facile.
lol
Kind of like cryopreservation with cryoprotectants vs ixation? Is it too easy/cheating? This was one of Darwin’s critiques. To me I have always liked to “cheat” by making things easy when possible
It took John Harrison nineteen years to build H-3. Historians and biographers cannot explain why Harrison—who turned out a turret clock in two years flat when he had scant experience to guide him, and who made two revolutionary sea clocks within nine years—should have lingered so long in the workshop with H-3. No one suggests that the workaholic Harrison dallied or became distracted. Indeed, there is evidence that he did nothing but work on H-3, almost to the detriment of his health and family, since the project kept him from pursuing most other gainful employment.
lol impressive/love this guy
Harrison loved it, and said so more clearly than he ever expressed another thought: “I think I may make bold to say, that there is neither any other Mechanical or Mathematical thing in the World that is more beautiful or curious in texture than this my watch or Timekeeper for the Longitude . . . and I heartily thank Almighty God that I have lived so long, as in some measure to complete it.”
How he came to master the jeweling of his Watch remains one of the most tantalizing secrets of H-4. Harrison’s description of the watch simply states that “The pallets are diamonds.” No explanation follows as to why he chose this material, or by what technique he shaped the gems into their crucial configuration. Even during the years when the Watch was dissected and inspected by committees of watchmakers and astronomers as it went through the mill of repeated trials, no recorded question or discussion came up regarding the diamond parts.
recently as fifty years ago, it lay in its original box, with the cushion and winding key. They have since been lost in the course of using H-4—transferring it from one place to another, exhibiting it, winding it, running it, cleaning it, transferring it again. In 1963, despite the sobering lesson of the lost box, H-4 visited the United States as part of an exhibition at the Naval Observatory in Washington. Harrison’s big sea clocks,
Estimating the pace of this natural process of attrition, curators suppose that within three or four centuries, H-4 would become a very different object from the one Harrison bequeathed to us three centuries ago. In its present state of suspended animation, however, H-4 may look forward to a well-preserved life of undetermined longevity. It is expected to endure for hundreds of years, if not thousands—a future befitting the timepiece described as the Mona Lisa or The Night Watch of horology.
In all fairness, Maskelyne is more an antihero than a villain, probably more hardheaded than hardhearted. But John Harrison hated him with a passion, and with good reason. The tension between these two men turned the last stretch of the quest for the longitude prize into a pitched battle. Maskelyne took up, then embraced, then came to personify the lunar distance method. The man and the method melded easily, for Maskelyne, who put off marrying until he was fifty-two, enslaved himself to accurate observation and careful calculation. He kept records of everything, from astronomical positions to
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This made him about forty years younger than John Harrison, although he seemed never to have been young. Described by a biographer early on as “rather a swot” and “a bit of a prig,” he threw himself into the study of astronomy and optics with every intention of becoming an important scientist.
Unlike John Harrison, who had no formal education, Nevil Maskelyne attended Westminster School and Cambridge University. He worked his way through college, performing menial tasks in exchange for reduced tuition.
Halley argued convincingly that lots of careful observations of the transit, taken from widely separated points on the globe, would reveal the actual distance between the Earth and the sun.
Therefore, the board concluded in its final report in August 1762, “the Experiments already made of the Watch have not been sufficient to determine the Longitude at Sea.” H-4 must needs submit to a new trial, under stricter scrutiny. Back to the West Indies with it, and better luck next time. Instead
His death, at sixty-nine, may have seemed less premature, though Maskelyne swore his mentor’s life had been unduly shortened by hard labor on the lunar tables.
I wasted time, and now doth time waste me; For now hath time made me his numbering clock; My thoughts are minutes.
Great quote
Only the eyebrows, raised at the center, and the lines between them, betray the man’s cautious craftsmanship, his nagging concerns.
Furrowed eyebrows are a sign of diligent work?
But this stupendous success gained Harrison only a small victory. The Watch and its maker still had lots of explaining to do. 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.
chorus of four captains from the East India Company, whom he’d brought with him, parroted these sentiments exactly. They had all used the procedure, many times, they said, just as it was outlined by Maskelyne in The British Mariner’s Guide, and they always managed to compute their longitude in a matter of a mere four hours.
Lord Egmont, the chairman of the board, gave Harrison his comeuppance: “Sir . . . you are the strangest and most obstinate creature that I have ever met with, and, would you do what we want you to do, and which is in your power, I will give you my word to give you the money, if you will but do it[!]”
The astronomer royal declared himself more than willing to undertake responsibility for the work. All he needed from the board, as official publisher, was the funding to pay salaries for a pair of human computers who could hash out the mathematics, plus the printer’s fees.
Maskelyne produced the first volume of the Nautical Almanac and Astronomical Ephemeris in 1766, and went on supervising it until his dying day. Even after his death, in 1811, seamen continued relying on his work for an additional few years, since the 1811 edition contained predictions straight through to 1815.
The Almanac represents Maskelyne’s enduring contribution to navigation—and the perfect task for him, too, as it embodied an abundance of excruciating detail: He included twelve full pages of data for each month, abbreviated and in fine print, with the moon’s position calculated every three hours vis-à-vis the sun or the ten guide stars. Everyone agreed, the Almanac and its companion volume, the Tables Requisite, provided the surest way for mariners to fix their positions at sea.
Although H-4 had traveled on a boat, accompanied by Larcum Kendall, down the Thames to Greenwich for its trial, the three large sea clocks rumbled and bumped their way there through the streets of London in an unsprung cart. We need not imagine Harrison’s response. The enamel paste medallion portrait of him in profile by James Tassie, which dates from about 1770, depicts the aging watchmaker’s thin lips decidedly downturned.
Practically pickled in brine, sauerkraut keeps forever aboard ship—or at least as long as the duration of a voyage around the world.
