Longitude

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Longitude Page 9

by Dava Sobel


  On the very first leg of the journey, much cheese and many whole barrels of drink were found unfit for consumption. Captain Digges ordered them thrown overboard, precipitating a crisis. “This day,” reads a note in the journal of the ship’s master, “all the Beer was expended, the People oblidged to drink water.” William promised a speedy end to the distress, as he reckoned with H-4 that the Deptford would make Madeira within a day. Digges argued that the Watch was way off, as was the island, and offered to lay odds on the bet. Regardless, the next morning brought Madeira into sight—and fresh barrels of wine into the hold. At this juncture, Digges made Harrison a new offer: He would buy the first longitude timekeeper that William and his father put up for sale, the moment it became available. While still in Madeira, Digges wrote to John Harrison:

  “Dear Sir, I have just time to acquaint you . . . of the great perfection of your watch in making the island on the Meridian; According to our Log we were 1 degree 27 minutes to the Eastward, this I made by a French map which lays down the longitude of Teneriffe, therefore I think your watch must be right. Adieu.”

  The Atlantic crossing took nearly three months. When the Deptford arrived at Port Royal, Jamaica, on January 19, 1762, the Board’s representative John Robison set up his astronomical instruments and established local noon. Robison and Harrison then synchronized their watches to fix the longitude of Port Royal by the time difference between them. H-4 had lost only five seconds—after 81 days at sea!

  Captain Digges, a great one for giving credit where it was due, ceremonially presented William— and his father, in absentia—with an octant to commemorate the successful trial. Curators at the National Maritime Museum, where this particular trophy-instrument is now displayed, note on a comment card that it seems “an odd present, perhaps, for someone trying to make the Lunar-Distance Method of determining Longitude redundant.” It must be the case that Captain Digges had seen a bullfight somewhere, and by this gesture he was awarding William the ears and tail of the vanquished animal. What’s more, even with the Watch in hand to tell the time in London, Digges would still need his octant to establish local time at sea.

  A little over a week after they reached Jamaica, William, Robison, and the Watch went back to England aboard the Merlin. With worse weather on the return, William worried constantly about keeping H-4 dry. The rough seas leapt onto the ship, often submerging the decks under two feet of water and leaking a good six inches into the captain’s cabin. Here poor seasick William wrapped the Watch in a blanket for protection, and when the blanket got soaked, he slept in it to dry the cloth with his body heat. William ran a raging fever by the end of the voyage, thanks to these precautions, but felt vindicated by the result. Upon its arrival home on March 26, H-4 was still ticking. And its adjusted total error, outbound and homebound combined, amounted to just under two minutes.

  The prize should have gone to John Harrison then and there, for his Watch had done all that the Longitude Act demanded, but events conspired against him and withheld the funds from his deserving hands.

  First there was the evaluation of the trial, which came up at the next meeting of the Board of Longitude, in June. Having stipulated the four keys and the two astronomers, the board now called for three mathematicians to check and recheck the data on the time determinations at Portsmouth and Jamaica, as both of these suddenly seemed insufficient and inaccurate. The commissioners also complained that William had failed to follow certain rules set down by the Royal Society for establishing the longitude at Jamaica by the eclipses of Jupiter’s moons—something William didn’t realize he was required to do, and wouldn’t have known how to do in any case.

  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 of £20,000, John 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.

  Maskelyne, defender of the rival method, had arrived back in London from St. Helena in May 1762, hot on William’s heels, and quite flush with accomplishment. He immediately cemented his future reputation by publishing The British Mariner’s Guide—an English translation of Mayer’s tables, plus directions for their use.

  Mayer himself had died in February, at thirty-nine, the victim of a virulent infection. Then Bradley, the astronomer royal, died in July. 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.

  The Harrisons discovered immediately that the loss of Bradley from the Board of Longitude offered no reprieve. His death failed to soften the hard-nosed attitude of the other commissioners. All that summer, as the post of astronomer royal fell vacant and then was filled through the appointment of Nathaniel Bliss, William corresponded with the board members to vindicate the Watch. He took hard knocks at two board meetings in June and August, and carried the discouraging words home to his father.

  As soon as Bliss took his ex officio seat on the Board of Longitude as the fourth astronomer royal, he took aim at the Harrisons. Like Bradley before him, Bliss was all for lunars. He insisted that the Watch’s so-called accuracy was a mere chance occurrence, and he did not predict a precision performance on the next trial.

  None of the astronomers or admirals on the board had any knowledge about the Watch or what made it run so regularly. They may have been incapable of understanding its mechanism, but they began hounding Harrison early in 1763 to explain it to them. This was a matter of both intellectual curiosity and national security. The Watch had value, for it seemed an improvement over the ordinary watches used to time the taking of lunars. The Watch might even stand in for the lunars in foul weather, when the moon and stars disappeared. Then, too, John Harrison wasn’t getting any younger. What if he died and took the potentially useful secret to the grave with him? What if William and the Watch went down together in some nautical disaster on the next trial? Clearly, the board needed a full disclosure on the timekeeper before they sent it back to sea.

  The French government dispatched a small contingent of horologists, Ferdinand Berthoud among them, to London in the hope that Harrison would reveal the Watch’s inner workings. Harrison, understandably wary by this time, shooed the French away, and begged his own countrymen to give him some assurance that no one would pirate his idea. He also asked Parliament for £5,000, to put teeth into their promise of protecting his rights. These negotiations quickly reached an impasse. No money and no information changed hands.

  Finally, in March of 1764, William and his friend Thomas Wyatt boarded H.M.S. Tartar and sailed to Barbados with H-4. The Tartar’s captain, Sir John Lindsay, oversaw this first phase of the second trial, and monitored the handling of the Watch on the way to the West Indies. Arriving ashore on May 15, prepared to compare notes with the board-appointed astronomers who had preceded him to the island aboard the Princess Louisa, William found a familiar face. There at the observatory, standing ready to judge the performance of the Watch, was Nathaniel Bliss’s handpicked henchman, none other than the Reverend Nevil Maskelyne.

  Maskelyne was undergoing something of a second trial himself, he had complained to the locals. His lunar distance method had clearly shown itself the supreme solution to the longitude problem on the voyage to St. Helena. And this time, en route to Barbados, he boasted, he was sure he’d clinched the case and secured the prize.

  When William heard word of these claims, he and Captain Lindsay challenged Maskelyne’s fitness to judge H-4 impartially. Maskelyne was outraged by their accusations. He became huffy, then nervous. In his disquieted condition, he botched the astronomical obse
rvations—even though all those present recalled there wasn’t a cloud in the sky.

  12.

  A Tale of Two

  Portraits

  How sour sweet music is

  When time is broke and no proportion kept!

  So is it in the music of men’s lives.

  I wasted time, and now doth time waste me;

  For now hath time made me his numbering clock;

  My thoughts are minutes.

  —WILLIAM SHAKESPEARE, Richard II

  Two compelling likenesses of John Harrison, both made during his lifetime, survive into ours. The first is a formal portrait in oils by Thomas King, completed sometime between October 1765 and May 1766. The other is an engraving by Peter Joseph Tassaert, from 1767, obviously taken from the painting, which it copies in almost every detail. In all details, really, except one—and this one difference tells a story of degradation and despair.

  The painting now hangs in the gallery at the Old Royal Observatory. It shows Harrison as a man to be reckoned with. Dressed in a chocolate brown frock coat and britches, he sits surrounded by his inventions, including H-3 at his right and the precision gridiron-pendulum regulator, which he built to rate his other timepieces, behind him. Even seated he assumes an erect bearing and a look of self-satisfied, but not smug, accomplishment. He wears a gentleman’s white wig and has the clearest, smoothest skin imaginable. (The story of Harrison’s becoming fascinated with watch-works in childhood, while recuperating from an illness, holds that he suffered a severe case of smallpox at the time. We must conclude, however, that the tale is tall, or that he experienced a miraculous recovery, or that the artist has painted out the scars.)

  His blue eyes, though a bit rheumy at seventy-plus years of age, direct a level gaze. Only the eyebrows, raised at the center, and the lines between them, betray the man’s cautious craftsmanship, his nagging concerns. He holds his left arm akimbo, hand on hip. His right forearm rests on a table, and in his fingers is . . . the Jefferys pocket watch!

  Where is H-4? It was long finished by this time, and always the apple of his eye. Surely Harrison would have insisted on having it pose with him. Indeed, it does pose with him in the Tassaert engraving. Strange how the mezzotint departs from the oil at the point of Harrison’s right wrist. His hand is empty in this image, upturned and vaguely gesturing toward the Watch, now lying on the table, a bit foreshortened by perspective, atop some drawings of itself. Admittedly, the timekeeper looks too large for Harrison to cradle comfortably in his palm, as he could do with the Jefferys watch, which was only half the size of H-4.

  The reason H-4 is missing from the oil portrait is that Harrison didn’t have it in his possession at the sittings. It was fudged in later, when Harrison’s growing fame as “the man who found Longitude” occasioned the creation of the engraving. The intervening events stressed Harrison to the limits of his forbearance.

  After the fractious second trial of the Watch in the summer of 1764, the Board of Longitude allowed months to pass without saying a word. The commissioners were waiting for the mathematicians to compare their computations of H-4’s performance with the astronomers’ observations of the longitude of Portsmouth and Barbados, all of which had to be factored into the judging. When they heard the final report, the commissioners conceded that they were “unanimously of opinion that the said timekeeper has kept its time with sufficient correctness.” They could hardly say otherwise: The Watch proved to tell the longitude within ten miles—three times more accurately than the terms of the Longitude Act demanded! 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.

  Adding to the tension of these developments, Nathaniel Bliss broke the long tradition of longevity associated with the title of astronomer royal. John Flamsteed had served in that capacity for forty years, Edmond Halley and James Bradley had each enjoyed a tenure of more than twenty, but Bliss passed away after just two years at the post. The name of the new astronomer royal—and ex officio member of the Board of Longitude—announced in January 1765, was, as Harrison no doubt predicted, his nemesis, Nevil Maskelyne.

  The thirty-two-year-old Maskelyne took office as fifth astronomer royal on a Friday. The very next morning, Saturday, February 9, even before the ceremony of kissing the king’s hand, he attended the scheduled meeting of the Board of Longitude as its newest commissioner. He listened while the thorny matter of Harrison’s payment was further debated. He added his approval to the proposed monetary awards for Leonhard Euler and the widow of Tobias Mayer. Then Maskelyne attended to his own agenda.

  He read aloud a long memorandum extolling the lunar distance method. A 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. They agreed with Maskelyne that the tables ought to be published and widely distributed, and then “this Method might be easily & generally practiced by Seamen.”

  This marked the beginning of a new groundswell in activity directed at institutionalizing the lunar distance method. Harrison’s chronometer may have been quick, but it was still a quirk, while the heavens were universally available to all.

  The year of 1765 brought Harrison further woes, in the form of a new longitude act from Parliament. This one—officially called 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.

  Harrison’s mood deteriorated. He stormed out of more than one board meeting, and was heard swearing that he would not comply with the outrageous demands foisted on him “so long as he had a drop of English blood in his body.”

  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[!]”

  Eventually, Harrison knuckled under. He turned in his drawings. He provided a written description. He promised to bare all before a committee of experts chosen by the board.

  Later that summer, on August 14, 1765, this illustrious party arrived at Harrison’s house in Red Lion Square for a watchmakers’ tribunal. Present were two of the Cambridge math professors Harrison referred to derisively as “Priests” or “Parsons,” the Reverend John Michell and the Reverend William Ludlam. Three reputable watchmakers attended: Thomas Mudge, a man keenly interested in making marine timekeepers himself, William Mathews, and Larcum Kendall, formerly apprentice to John Jefferys. The sixth committee man was the widely respected scientific instrument maker John Bird, who had fitted the Royal Observatory with mural quadrants and transit instruments for mapping the stars, and outfitted many scientific expeditions with unique devices.

  Nevil Maskelyne came along, too.

  Over the course of the next six days, Harrison dismantled the Watch piece by piece, explained—under oath—the function of each part, described how the various innovations worked together to keep virtually perfect time, and answered all the questions put to him. When it was over, the judges signed a certificate saying that they believed Harrison had indeed told them everything he knew.

  As the coup de grâce, the board insisted that Harrison now reassemble the Watch and surrender it, l
ocked in its box, to be sequestered (held for ransom, really) in a storeroom at the Admiralty. At the same time, he had to commence building the two replicas— without the Watch to serve as a guiding pattern, and stripped even of his original diagrams and description, which Maskelyne had delivered to the print shop so they could be copied, engraved, published in book form, and sold to the public at large.

  What a time to sit for a portrait. Yet it was at this juncture that Mr. King painted Mr. Harrison. A look of calm may have come over him late that fall, when he at last received the £10,000 he had been promised by the board.

  At the beginning of the New Year, 1766, Harrison heard for the second time from Ferdinand Berthoud, who arrived from Paris with high hopes of accomplishing what he had failed to do on his last trip in 1763: learn the details of H-4’s construction. Harrison felt little inclined to confide in Berthoud. Why should he divulge his secrets to anyone who couldn’t make him do so? Parliament had been willing to pay £10,000 to hear from Harrison what Berthoud seemed to expect for peanuts. On behalf of the French government, Berthoud offered £500 for a private tour of H-4. Harrison refused.

  Berthoud, however, before coming to London, had been in correspondence, watchmaker to watchmaker, with Thomas Mudge. Now that Berthoud was in town, he dropped in at Mudge’s shop in Fleet Street. Apparently, no one had told Mudge—or any of the other expert witnesses—that Harrison’s disclosure was supposed to be kept confidential. In the course of dining with the visiting horologist, Mudge waxed loquacious on the subject of H-4. He had held it in his hands and been privy to the discovery of its most intimate details, all of which he shared with Berthoud. He even drew sketches.

  As it turned out, Berthoud and the other continental clockmakers did not steal Harrison’s designs in the construction of their own marine timekeepers. Yet Harrison had cause to cringe at the casual manner in which his case was opened and aired.

 

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