The Day the World Discovered the Sun (10 page)

Sisson, who was modifying some of Irwin's marine chair designs, pulled out three models for close inspection. Sisson's shop—on The Strand, amid the clang and din of central London—crackled with the electricity of opportunity.

Though very talented at his craft, Sisson had a flighty attention span that left the dilettantish Lalande ill at ease. The craftsman had of late been pawning his handiwork for easy cash. His visitors were marked for the full-on pitch.

Out came a chair “mounted on a suspension with four pivots and two boots.” Sisson showcased a second seat, held high on a “knee joint from which a 6 foot pendulum hung, with the weight at the bottom in water.” Finally the French horologists viewed an eight-by-four-foot monstrosity “made up of two circles each having two pivots, but whose directions cross.”

Sisson, Lalande recorded, “is obliged to work in great haste, and so achieves nothing worthwhile. But nevertheless there is no one who has as much ability as he.”
²²

Lalande's two countrymen—the clockmaker Ferdinand Berthoud and the mathematician Charles Étienne Louis Camus—no doubt hoped for a similar welcoming the next day when they called on John Harrison at his nearby house in Red Lion Square.

More serious and steadfast in his persistence, Harrison was a man of defiant will who, for starters, had once dared to doubt the greatest scientific genius in history. In 1725 Sir Isaac Newton had informed the British Admiralty that two, and only two, practicable methods for finding longitude at sea existed: lunar longitudes and longitudes via the moons of Jupiter.
²³

Moreover, latitude at sea had always come courtesy of measurements of the sun and stars. Expecting manmade springs and gearwheels to solve longitude was almost an affront to the heavens. As the French mathematician Jean-Baptiste Morin put it, “It would be folly to undertake it. . . . I don't know if the Devil himself could do it.”
²⁴

To both Lalande and Maskelyne—commanding increasing authority in their respective countries—Newton and Morin had stated what to their generation of natural philosophers had become self-evident. Marine chronometers were a pointless dream, a wild and distracted sprite. Longitude's future was with the moon.

But Harrison simply would not go away. A generation before, in 1735, Harrison completed his first sea clock—a portmanteau-size, seventy-two-pound, gear-shafted dial box that flexed long arms of spring-propelled brass spheres. The next year the Royal Society sent Harrison and his temporal dynamo to Lisbon to test it out. Absurd though the chronometer looked, it yielded impressive results on the sea journey there and back. For starters, when Harrison's ship first returned to the channel, Harrison accurately informed the captain which English islands were coming into view. The navigation officers had instead located the ship sixty-eight miles east of where it actually was.

The English Board of Longitude awarded Harrison £500 to develop a better chronometer. So Harrison completed his second machine in
1739, making a timekeeper bigger and heavier than the first. It still wasn't reliable or rugged enough, however. In the next twenty years, he tinkered and fussed and ultimately made two breakthrough designs that better compensated for jostling seas and temperature extremes.
²⁵
Harrison finished his third marine chronometer in 1759, another unwieldy box. Then, just one year later, he was ready to unveil his true masterpiece—a palm-size, three-pound pocket watch with all the ocean readiness of his previous chronometers.

This fourth Harrison design, presented to the Board of Longitude in July 1760, was the stroke of genius that had set French spies to knocking.

Miscommunications in Harrison's 1761 transatlantic trial of his sea watch left commissioners from the Board of Longitude unsatisfied, concluding that another transatlantic trial was needed. And so, in the spring of 1763, the master craftsman awaited the final opportunity to vindicate himself.

Harrison had in fact shown his masterpiece watch to Lalande three Fridays before, on April 22. But that was before Berthoud and Camus had arrived in England. Lalande knew nothing about watchmaking. Lalande was no more able to appreciate Harrison's meticulous handiwork as Harrison was able to recognize the enduring brilliance of the recent breakthroughs in lunar longitudes.

So Lalande, Berthoud, and Camus called on Harrison on Monday, May 9. Harrison obliged and opened his home to his nation's former enemies, setting out for their analysis and perusal his first three sea clocks.

Berthoud, Lalande noted, “found these pieces very beautiful, very clever, very well executed. And though the regularity of [Harrison's] watch was quite difficult for him to believe, he was even more impatient to see it after seeing the three clocks.”
²⁶

Lalande translated his countrymen's requests to inspect Harrison's pièce de résistance. This is where the tour stopped. Parliament and the
Board of Longitude may have been hopelessly naive in mandating open inspections of Harrison's handiwork. The craftsman himself, however, was a little more cagey.

Berthoud was left to gather what intelligence he could from Harrison's first three chronometers—and from Lalande's inexpert recall of Harrison's marine watch.

Nevertheless, Berthoud had learned enough to return to Paris and reconfigure his whole clock-making enterprise. Four of Harrison's innovations soon found their way into Berthoud's Horloge Marine 2. And Berthoud further turned out two marine watches, building on the knowledge and inspiration Harrison had imparted.
²⁷

Charles Green had everything now before him. After Charles Mason departed for the 1761 Venus transit mission, Green assumed Mason's role as second in command at the Royal Greenwich Observatory. After Green's boss—James Bradley, Astronomer Royal—died in July 1762, the next Astronomer Royal was sickly and spent most of his time at home in Oxford. Twenty-nine-year-old Charles Green was left to handle most of the duties himself. The young man had, in effect, taken the reins of arguably the most prestigious astronomical job in the world.

In September 1763, with rising star Nevil Maskelyne, Green set sail for Bridgetown, Barbados, on a new transatlantic test of the top contending longitude technologies. The original inventor of the marine chairs, Christopher Irwin, had installed two working prototypes onboard their ship, the HMS
Princess Louisa
. During the voyage, Green and Maskelyne tried out these “marine machines” in a real oceanic setting. The tests proved a disaster. The astronomers each attempted on more than one night to sight Jupiter and its moons through the chair's telescope, only to find that the planet wobbled and zipped around the
scope's field of view. Close monitoring of the planet and its moons was impossible. The creaking contraption could not compensate for the unsteady sea—even on a calm night. The chair, Maskelyne wrote in a private letter to his brother Edmund, “proves a mere bauble, not in the least useful for the purpose intended.”
²⁸

Green and Maskelyne also took multiple lunar longitudes using both Maskelyne's mahogany quadrant and a brass sextant on loan from the Board of Longitude. Their final longitude, just before making landfall off the coast of Barbados (thus making it independently verifiable), was a half degree off the true value. Combined with the lunars Maskelyne took in his Venus transit voyages, he now thought he had all the proof he needed to secure the Longitude Prize.

Still, the Board of Longitude had sent Green and Maskelyne to Barbados primarily to provide precise, independently derived times and longitudes that would enable testing of John Harrison's marine chronometer, which would be arriving on a separate ship.

To Maskelyne, Bridgetown's luscious tropical setting simply meant more cloudless nights for practicing his science. “This country is much better adapted for celestial observations than England, the air being generally much purer & serener, insomuch that for this month past I have miss'd scarce any observations that occur'd,” Maskelyne wrote to his brother.
²⁹

The welcoming, aquamarine waters of Barbados bathed the travelers' afternoons and evenings in the sun's reflected glow. The seaside Fort Willoughby provided an open-air observatory whose warm and gentle evening breezes gave English astronomers—accustomed to night shivers huddled over a telescope—a new, tropical standard of comfort. But those same ocean breezes carried so much moisture, in fact, that exposed steel parts or instruments could rust overnight. Copper spoons portioned out the fresh cane sugar for their tea.
³⁰

December's cooling retained the warmth of a pleasant Hampshire summer, and colors of the Yuletide season—snowy whites and deep
scarlets—blossomed on wild potato vines and Christmas bushes. Maskelyne and Green set to moving inland and sited a new observatory at the foot of Constitution Hill, 750 yards from their beachside Fort Willoughby accommodations. The eight-by-twelve-foot wooden shed was even tinier than the island's slave shanties but concealed an outsize purpose. Here the competing technologies vying to reshape the entire world would feel the cold hand of the scientific method.

Cold cash was on the line too. A prize of up to £20,000 (more than $5 million today) awaited Harrison or Maskelyne if either the marine chronometer or the
British Mariner's Guide
could definitively fulfill the terms of the 1714 Longitude Act. The two key criteria were reliable longitudes accurate down to one-half of a degree and a method that was “practicable and useful at sea.”

At 1:39
AM
on January 7, 1764, Maskelyne recorded the exact time of what would be sixteen immersions or emersions of Jupiter's moons over the coming eight months at the new location.
³¹
Although not even the finest of the pitiful marine chairs could make Jovian measurements possible onboard a ship, on land Jupiter was still the quickest and easiest route to precision longitudes.

Celestially derived longitudes may have been widely considered the only serious methods around, but the rapidly advancing watchmaking technology knew no such human prejudices. A showdown was coming. And when the HMS
Tartar
first appeared in Bridgetown's Carlisle Bay on May 13, the Caribbean winds fanned the smoldering flame.

John Harrison's son William, onboard the
Tartar
to help test the marine watch in the stead of his elderly father, had barely disembarked the ship before he'd learned of Maskelyne boasting that the prize was his. The Board of Longitude, Harrison recorded in his journal, had allegedly all but assured Maskelyne he'd already won.
³²
Harrison's stunning marine chronometer longitudes on his voyage to Barbados—accurate down to one-sixth of a degree—now seemed irrelevant.
³³
Was true scientific proof to be honored anywhere inside Maskelyne and Green's slat-roofed shack?

Harrison was livid. At dawn the next morning, Harrison and Sir John Lindsay, captain of the
Tartar
, appeared outside the observatory. Besmirched honor of this degree might, in a dispute between peers of the realm, call for a pair of pistols at this early hour. As it was, dueling words sufficed. The prize money looming over everyone, Harrison said, made Maskelyne unfit to provide independent verification of the marine watch's longitudes.

Lindsay brokered an accord in which Green and Maskelyne alternated the days they would be checking the marine watch against the exact solar time—a crucial element of Harrison's claim to the prize. The captain and three other witnesses stayed as rooted as the palm trees throughout, a constant presence further assuring no shady results.

Sometime during the Barbados trials Green and Maskelyne too had let the tension of the moment get the better of their relationship. According to contemporary accounts of the Barbados trials, the two astronomers suffered some unspecified disagreement that ultimately killed their friendship.
³⁴

On June 4, Harrison and Green set sail for England, bringing with them the rarified marine watch—all too rarified, perhaps. For it was the fact that no copies of Harrison's watch had yet been made that now prevented the Board of Longitude from awarding Harrison the prize. A solution could only be “practicable,” they ruled, if it could be readily copied and affordably installed on English military and mercantile ships around the world.

Meanwhile, Maskelyne remained in Barbados until August, continuing further lunar observations he'd begun in St. Helena in 1761. Arriving in London in October, Maskelyne boasted that he'd once again used lunars to measure his ship's longitude down to the same level of accuracy Harrison claimed for his chronometer. Yet the lunar tables in Maskelyne's
British Mariner's Guide
were now beginning to lose their edge. Although technically extended all the way out to 1780, every successive month added more uncertainty to the lunar predictions Maskelyne had calculated the year before. To keep his claim alive, Maskelyne
would have to perform his own duplication rites too. A new almanac would be needed.

No clear winner emerged from Barbados. Yet both frontrunners had proved themselves worthy of continued royal attention and patronage. The Bridgetown standoff carried on, though the voyage itself was fading like so many sumptuous sunsets over Carlisle Bay.