Longitude

by Dava Sobel

  He took the Harrisons under his aegis and helped them circumvent the obdurate board, by appealing directly to the prime minister, Lord North, and to Parliament for “bare justice,” as William called it.

  With the government badgering the board, the longitude commissioners met on April 24, 1773, to trace the whole tortuous course of the Harrison case yet again, in front of two witnesses from Parliament. Then Harrison’s particulars came up for debate in Parliament three days later. At the king’s suggestion, Harrison dropped his legal blustering and simply appealed to the hearts of the ministers. He was an old man. He had devoted his life to these endeavors. And although he had succeeded, he was rewarded with only half a prize plus new—and impossible—demands.

  This approach carried the day. The final resolution took a few more weeks to go through channels, but at last, at the end of June, Harrison received £8,750. This amount nearly totaled the remainder of the longitude prize due him, but it was not the coveted prize. Rather, the sum was a bounty awarded by the benevolence of Parliament—in spite of the Board of Longitude, instead of from it.

  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 This new act of 1774 repealed all the previous legislation on longitude.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 year’s testing at Greenwich followed by two voyages around Great Britain (one heading east first, the other west), as well as any other voyages to whatever destinations the board might specify, culminating in up to twelve additional months of postvoyage observation at the Royal Observatory. Maskelyne was heard chortling that the act “had given the mechanics a bone to pick that would crack their teeth.”

  These words proved prophetic, for the prize money was never claimed.

  Harrison, however, felt further vindicated in July 1775, when Cook returned from his second voyage with bouquets of praise for the method of finding longitude by means of a timekeeper.

  “Mr Kendall’s Watch (which cost £450),” the captain reported, “exceeded the expectations of its most zealous advocate and by being now and then corrected by lunar observations has been our faithful guide through all vicissitudes of climates.”

  The log of H.M.S. Resolution reveals numerous references to the timekeeper, which Cook called “our trusty friend the Watch,” and “our never failing guide, the Watch.” With its help, he made the first—and highly accurate—charts of the South Sea Islands.

  “It would not be doing justice to Mr Harrison and Mr Kendall,” Cook also noted in the log, “if I did not own that we have received very great assistance from this useful and valuable timepiece.”

  So enamored was Cook of K-1 that he carried it out on his third expedition, on July 12, 1776. This voyage was not so fortunate as the first two. Despite the great diplomacy of this renowned explorer, and his efforts to respect the native peoples of the lands he visited, Captain Cook ran into serious trouble in the Hawaiian archipelago.

  At their initial encounter with Cook, who was the first white man they had ever seen, the Hawaiians hailed him as the incarnation of their god, Lono. But when he returned to their island some months later from his sorties around Alaska, tensions mounted, and Cook had to make a speedy departure. Within days, unfortunately, damage to the Resolution’s foremast forced him back to Kealakekua Bay. In the ensuing hostilities, Cook was murdered.

  Almost at the instant the captain died in 1779, according to an account kept at the time, K-1 also stopped ticking.

  14.

  The Mass Production

  of Genius

  The stars are not wanted now; put out every one,

  Pack up the moon and dismantle the sun.

  —W. H. AUDEN, “Song”

  When John Harrison died, on March 24, 1776, exactly eighty-three years to the day after his birth in 1693, he held martyr status among clockmakers.

  For decades he had stood apart, virtually alone, as the only person in the world seriously pursuing a timekeeper solution to the longitude problem. 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. Indeed, some modern horologists claim that Harrison’s work facilitated England’s mastery over the oceans, and thereby led to the creation of the British Empire—for it was by dint of the chronometer that Britannia ruled the waves.

  In Paris, the great clockmakers Pierre Le Roy and Ferdinand Berthoud advanced their montres marines and horloges marines to perfection, but neither of these two archrivals ever produced a timekeeper design that could be reproduced quickly and cheaply.

  Harrison’s Watch, as the Board of Longitude never tired of reminding him, was too complex for ready reproduction, and awfully expensive, too. When Larcum Kendall copied it, the commissioners paid him a fee of £500 for his two-plus years of effort. Asked to train other watchmakers to make more copies, Kendall backed off, on the grounds that the product was way too pricey.

  “I am of the opinion,” Kendall told the board, “that it would be many years (if ever) before a watch of the same kind with that of Mr. Harrison’s could be afforded for £200.”

  Meanwhile, a seaman could buy a good sextant and a set of lunar distance tables for only a fraction of that sum, about £20. With such a glaring cost comparison between the two methods, the marine timekeeper had to provide more than ease of use and greater accuracy. It had to become more affordable.

  Kendall tried to topple Harrison with a cheap imitation of the original Watch. Having produced K-1 in H-4’s image, Kendall completed K-2 in 1772 after a second two-year period of devotion. He was paid £200 for it by the Board of Longitude. Although K-2 was about the size of K-1 and H-4, it was internally inferior, because Kendall had omitted the remontoire, the mechanism that doles out the power from the mainspring so the force applied to the timekeeping element stays the same whether the watch has just been wound up or is nearly wound down. Absent the remontoire, the timepiece ran fast at first, after winding, and then slowed down. The H-4 remontoire had been hailed by all who knew enough to appreciate it. Without it, K-2 proved undistinguished during tests at Greenwich.

  The sea life of K-2, however, encompasses some of the most famous voyages in the annals of the oceans. The timepiece ventured out with a North Polar expedition, spent several years in North America, sailed to Africa, and boarded H.M.S. Bounty under Captain William Bligh. The captain’s foul temper provides the stuff of legend, but an unsung part of his story holds that when the mutiny on the Bounty occurred, in 1789, the crew made off with K-2. They kept the watch at Pitcairn Island until 1808, when the captain of an American whaling ship bought it and launched K-2 on yet another round of adventures.

  In 1774 Kendall made a third, still cheaper time-keeper (minus the diamonds this time), which he sold to the board for £100. K-3 performed no better than K-2, yet it shipped passage on H.M.S. Discovery to take part in Cook’s third tour. (Bligh, incidentally, served as sailing master under Captain Cook on this voyage. And although Cook was killed in Hawaii, Bligh went on to become governor of New South Wales, Australia, where he was imprisoned by army mutineers during the Rum Rebellion.)

  None of Kendall’s own innovations compared with his masterful copy work on K-1. He soon ceased trying new ideas, already outstripped by others far more inventive than he.

  One of these was watchmaker Thomas Mudge of Fleet Street, who had been apprenticed in his youth to “Honest” George Graham. Like Kendall, Mudge attended the dissection and discussion of H-4 at Harrison’s house. Later he indiscreetly divulged those details at dinner with Ferdinand Berthoud, though he swore he intended no wrongdoing. Mudge had an earned reputation as a fine craftsman and a fair tradesman. He constructed his first marine timekeeper in 1774, incorporating and improving upon many of Harrison’s ideas. Enviably executed inside and out, the Mudge chronometer boasted a special form of remontoire
and an eight-sided gilt case crowned by a face full of silver filigree. He later made another two in 1777, called “Green” and “Blue”—a matched pair, identical except for the colors of their cases—to compete in earnest for the remaining £10,000 of the longitude prize.

  While testing Mudge’s first timekeeper at Greenwich, Astronomer Royal Nevil Maskelyne unwittingly made it stop running through mishandling, and within another month accidentally broke the device’s mainspring. The much-disgruntled Mudge then took Harrison’s place as Maskelyne’s new sparring partner. The two kept up a lively exchange of opinions until Mudge became ill in the early 1790s. At that point, Mudge’s lawyer son, Thomas Jr., carried on the dispute, some of it in pamphlet form, and won a £3,000 payment from the Board of Longitude in recognition of his father’s contributions.

  While Kendall and Mudge each built three marine timekeepers apiece in the course of a lifetime, and Harrison five, the watchmaker John Arnold finished several hundred of high quality. His prodigious output may have been even greater than we know, since Arnold, a canny marketer, often engraved “No. 1” on a watch that was by no means the first of its kind in a particular product line. The secret to Arnold’s speedy manufacture lay in the way he farmed out the bulk of the routine work to various craftsmen and did only the difficult parts, especially the meticulous adjusting, himself.

  As Arnold’s star rose, the word chronometer came into general usage as the preferred name for a marine timekeeper. Jeremy Thacker had coined this term in 1714, but it didn’t catch on until 1779, when it appeared in the title of a pamphlet by Alexander Dalrymple of the East India Company, Some Notes Useful to Those Who Have Chronometers at Sea.

  “The machine used for measuring time at sea is here named chronometer,” Dalrymple explained, “[as] so valuable a machine deserves to be known by a name instead of a definition.”

  Arnold’s first three box chronometers, which he supplied to the Board of Longitude, traveled, as did K-1, with Captain Cook. The whole Arnold trio sailed on the 1772-75 voyage to the Antarctic and the South Pacific. The “vicissitudes of climates,” as Cook described the global weather range, caused Arnold’s clocks to go poorly. Cook declared himself unimpressed with the way they performed aboard his two ships.

  The board cut off Arnold’s funding as a result. But this action, instead of discouraging the young watchmaker, spurred him on to new concepts, all of which he patented and perpetually improved. In 1779 he created a sensation with a pocket chronometer, called No. 36. It truly was small enough to be worn in the pocket, and Maskelyne and his deputies carried it in theirs for thirteen months to test its accuracy. From one day to the next, it never gained or lost more than three seconds.

  Meanwhile, Arnold continued to hone his skill at mass production. He opened a factory at Well Hall, south London, in 1785. His competitor, Thomas Mudge Jr., tried to run a factory, too, turning out some thirty imitations of his father’s chronometers. But Thomas Jr. was a lawyer, not a clockmaker. No timekeeper that came from the junior Mudge works ever matched the accuracy of the elder’s three originals. And yet, a Mudge chronometer cost twice as much as one of Arnold’s.

  Arnold did everything methodically. He established his reputation in his early twenties by making a marvelous miniature watch, only half an inch in diameter, which he mounted in a finger ring and presented to King George III as a gift in 1764. Arnold married after he had laid out his lifework as a maker of marine timekeepers. He chose a wife who was not only well-to-do but also well prepared to improve his business as well as his home life. Together they invested their all in their only child, John Roger Arnold, who also tried to further the family enterprise. John Roger studied watchmaking in Paris under the finest teachers of his father’s choosing, and when he became full partner in 1784, the company name changed to Arnold and Son. But Arnold Sr. always remained the better watchmaker of the two. His brain bubbled over with myriad ways to do things, and he seems to have tried them all in his chronometers. Most of his best mousetraps were artful simplifications of things Harrison had pioneered in a clever but complicated way.

  Arnold’s biggest competition came from Thomas Earnshaw, who ushered in the age of the truly modern chronometer. Earnshaw reduced Harrison’s complexity and Arnold’s prolificacy to an almost platonic essence of chronometer. Equally important, he brought one of Harrison’s biggest ideas down to small scale at last, by devising a timekeeping element that needed no oil.

  Earnshaw lacked Arnold’s finesse and business sense. He married a poor woman, fathered too many children, and mismanaged his financial affairs so badly that he had to serve time in debtors’ prison. Nevertheless, it was 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.

  In addition to being commercial competitors, Arnold and Earnshaw became sworn enemies in a fight over their conflicting originality claims for the chronometer’s key component, called the spring detent escapement. An escapement lies at the core of any watch or clock; it alternately blocks and releases the movement at a rhythm set by the clock’s regulator. Chronometers, which aspire to perfect timekeeping, are defined by the design of their escapement. Harrison had used his grasshopper escapement in the big sea clocks, then turned to a brilliant modification of the old-fashioned verge escapement in H-4. Mudge won lasting acclaim for his lever escapement, which appeared in nearly all mechanical wrist- and pocket watches manufactured through the middle of the twentieth century, including the famous Ingersoll dollar watch, the original Mickey Mouse watch, and the early Timex watches. Arnold appeared entirely happy with his pivoted detent escapement—until he heard about Earnshaw’s spring detent escapement in 1782. It was an “Aha!” moment for Arnold, who realized right away that replacing pivots with a spring would eliminate any need to oil that part of the works.

  Arnold couldn’t get a look at Earnshaw’s escapement, but he contrived his own version, then rushed to the patent office with sketches. Earnshaw, who lacked the money to patent his invention, nevertheless had proof of paternity in watches he’d made for others—and in the joint-patent bargain he had arranged with established watchmaker Thomas Wright.

  The fracas between Arnold and Earnshaw polarized the whole community of London watchmakers, not to mention the Royal Society and the Board of Longitude. Great quantities of ink and bile were expended by both parties and their various supporters. Enough evidence emerged to prove that Arnold had peeked inside one of Earnshaw’s watches before he filed his patent, but who was to say he hadn’t been thinking of such a mechanism on his own? Arnold and Earnshaw never settled their differences to either one’s satisfaction. Indeed, the brouhaha lives on today among historians who continue to find new evidence and take sides in the old argument.

  The Board of Longitude, egged on by Maskelyne, in 1803 declared Earnshaw’s chronometers to run better than any previously tried at the Royal Observatory. Maskelyne had at last met a watchmaker he liked, though it is not clear why he liked him. Whatever the reason, Earnshaw’s fine craftsmanship provoked the astronomer royal to proffer advice, encouragement, and opportunities for clock repair work at the Observatory— a pattern of patronage that persisted for more than a decade. Earnshaw, however, who described himself as “irritable by nature,” gave Maskelyne the hard time he had no doubt come to expect from “mechanics.” For example, Earnshaw attacked Maskelyne’s yearlong trials for testing chronometers, and succeeded in getting these shortened to six months.

  In 1805, the Board of Longitude awarded Thomas Earnshaw and John Roger Arnold (Arnold Sr. having died in 1799) equal awards of £3,000 each—the same amount that had gone to Mayer’s and Mudge’s heirs. Earnshaw shouted and published his indignation, for he thought he deserved a larger share. Fortunately for Earn
shaw, he was making a comfortable living by then from his commercial success.

  Captains of the East India Company and the Royal Navy flocked to the chronometer factories. At the peak of the Arnold-Earnshaw contretemps in the 1780s, prices had come down to about £80 for an Arnold box chronometer and £65 for an Earnshaw. Pocket chronometers could be bought for even less. Although naval officers had to pay for a chronometer out of their own pockets, most were pleased to make the purchase. Logbooks of the 1780s bear this out, for they begin to show daily references to longitude readings by timekeeper. In 1791, the East India Company issued new logbooks to the captains of its commercial vessels, with preprinted pages that contained a special column for “longitude by Chronometer.” Many navy captains continued to rely on lunars, when the skies allowed them to, but the chronometer’s credibility grew and grew. In comparison tests, chronometers proved themselves an order of magnitude more precise than lunars, primarily because they were simpler to use. The unwieldy lunar method, which demanded a series of astronomical observations, ephemerides consultations, and corrective computations, opened many doors through which error could enter.

  By the turn of the century, the navy had procured a stock of chronometers for storage in Portsmouth, at the Naval Academy, where a captain could claim one as he prepared to sail from that port. With supply small and demand high, however, officers frequently found the academy’s cupboard bare and continued to buy their own.

  Arnold, Earnshaw, and an increasing number of contemporaries sold chronometers at home and abroad for use on naval ships, merchant vessels, and even pleasure yachts. Thus the total world census of marine timekeepers grew from just one in 1737 to approximately five thousand instruments by 1815.

  When the Board of Longitude disbanded in 1828, at the repeal of the prevailing Longitude Act, its chief duty, ironically enough, had become the supervision of testing and assigning chronometers to ships of the Royal Navy. In 1829, the navy’s own hydrographer (chief chartmaker) took over the responsibility. This was a big job, as it included seeing to the rate setting of new machines and the repair of old ones, as well as the delicate transportation of the chronometers over land, from factory to seaport and back again.