Exactly: How Precision Engineers Created the Modern World. Simon Winchester

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СКАЧАТЬ more delicate parts of the watches: the notion that such work could possibly be done by the hand of a sixty-six-year-old John Harrison still beggars belief.

      Once his task was completed, he handed the finished watch over to the Admiralty for its crucial test. The instrument (in the care of Harrison’s son William, who acted as its chaperone) was taken aboard the HMS Deptford, a fifty-gun fourth-rate ship of the line, and sent out on a five-thousand-mile voyage from Portsmouth to Jamaica.^* Careful observation at the end of the trip showed the watch to have accumulated a timekeeping error of only 5.1 seconds, well within the limits of the longitude prize. Over the entire 147 days of a voyage that involved a complex and unsettling stormy return journey (in which William Harrison had to swaddle the timekeeper in blankets), the watch error was just 1 minute 54.5 seconds, a level of accuracy never imagined for a seaborne timekeeping instrument.

      And while it would be agreeable to report that John Harrison then won the prize for his marvelous creation, much has been made of the fact that he did not. The Board of Longitude prevaricated for years, the Astronomer Royal of the day declaring that a much better way of determining longitude, known as the lunar distance method, was being perfected, and that there was therefore no need for sea clocks to be made. Poor John Harrison, therefore, had to visit King George III (a great admirer, as it happens) to ask him to intercede on his behalf.

      A series of humiliations followed. H4 was forced to be tested once again, and recorded an error of 39.2 seconds over a forty-seven-day voyage—once again, well within the limits set by the Board of Longitude. Harrison then had to dismantle the watch in front of a panel of observers and hand his precious instrument to the Royal Observatory for a ten-month running trial to check (once again, but this time on a stable site) its accuracy. It was torturous and vexing for the now-elderly Harrison, who at seventy-nine was becoming increasingly and understandably embittered by the whole procedure.

      Finally, and thanks in large part to King George’s intervention, Harrison did get almost all his money. The popular memory of him, though, is of a genius hard done by, and his great clocks and the two sea watches, H4 and K1, remain the most potent memorials, three of them beating out the time steadily and ceaselessly as a reminder of how their maker, with his devotion to precision and accuracy in his craft work, helped so profoundly to change the world.

      THE ANTIKYTHERA MECHANISM, then, was a device remarkable and precise in its making and aspect, but its inaccuracy and understandably amateurish construction rendered it unreliable and, in practical terms, well-nigh useless. John Harrison’s timekeepers, though, were both precise and accurate, but given that they took years to make and perfect, and were the result of hugely costly craftsmanship, it would be idle to declare them either as candidates or as the fountainhead for true and world-changing precision. Also, though intending no disrespect to an indelible technical achievement, it is worth noting that John Harrison’s clockworks enjoyed perhaps only three centuries’ worth of practical usefulness. Nowadays, the brassbound chronometer in a ship’s chart room, just like the sextant kept in its watertight morocco box, is a thing more decorative than essential. Time signals of impeccable accuracy now come across the radio. The digital readout of longitude and latitude coordinates come to a ship’s bridge from a Global Positioning System’s (GPS) interrogation of faraway satellites. Clockwork machines, however beautifully their gears may be cut and enclosed in casings, however precious and intricately engraved, are a creation of yesterday’s technology, and are retained nowadays by and large for their precautionary value only: if the seagoing vessel loses all power, or if the master is a purist with a disdain for technology, then John Harrison’s works have real practical worth. Otherwise, his clocks gather dust and salt, or are kept in glass cases, and his name will begin to slip gradually astern, to vanish inevitably and soon in a sea fret of history, way stations at the beginning of the voyage.

      For precision to be a phenomenon that would entirely alter human society, as it undeniably has done and will do for the foreseeable future, it has to be expressed in a form that is duplicable; it has to be possible for the same precise artifact to be made again and again with comparative ease and at a reasonable frequency and cost. Any true and knowledgeable craftsman (just like John Harrison) may be able, if equipped with sufficient skill, ample time, and tools and material of quality, to make one thing of elegance and evident precision. He may even make three or four or five of the same thing. And all will be beautiful, and most will inspire awe.

      Large cabinets in museums devoted to the history of science (most notably at Oxford and Cambridge and Yale) are today filled with such objects. There are astrolabes and orreries, armillary spheres and astraria, octants and quadrants, and formidably elaborate sextants, both mural and framed, which are to be seen in particular abundance, most of them utterly exquisite, intricate, and assembled with a jeweler’s care.

      At the same time, all of each instrument was perforce made by hand. Every gear was hand-cut, as was every component part (every mater and rete and tympan and alidade, for example; astrolabes have their own quite large vocabulary), every tangent screw and index mirror (words relating to sextants are similarly various). Also, the assembly of each part to every other and the adjustment of the assembled whole—all had to be accomplished with, quite literally, fingertip care. Such an arrangement produced fine and impressive instruments, without a doubt, but given the manner in which they were made and how they were put together, they could necessarily have been available only in rather limited numbers and to a small corps d’élite of customers. They may have been precise, but their precision was very much for the few. It was only when precision was created for the many that precision as a concept began to have the profound impact on society as a whole that it does today.

      And the man who accomplished that single feat, of creating something with great exactitude and making it not by hand but with a machine, and, moreover, with a machine that was specifically created to create it—and I repeat the word created quite deliberately, because a machine that makes machines, known today as a “machine tool,” was, is, and will long remain an essential part of the precision story—was the eighteenth-century Englishman denounced for his supposed lunacy because of his passion for iron, the then-uniquely suitable metal from which all his remarkable new devices could be made.

      IN 1776, THE forty-eight-year-old John Wilkinson, who would make a singular fortune during his eighty years of life, had his portrait painted by Thomas Gainsborough, so he is far from an uncelebrated figure—but if not uncelebrated, then not exactly celebrated, either. It is notable that his handsome society portrait has for decades hung not in prominence in London or Cumbria, where he was born in 1728, but in a quiet gallery in a museum far away in Berlin, along with four other Gainsboroughs, one of them a study of a bulldog. The distance suggests a certain lack of yearning for him back in his native England. And the New Testament remark about a prophet being without honor in his own country would seem to apply in his case, as Wilkinson is today rather little remembered. He is overshadowed quite comprehensively by his much-better-known colleague and customer, the Scotsman James Watt, whose early steam engines came into being, essentially, by way of John Wilkinson’s exceptional technical skills.

      History will show that the story of such engines, which were so central to the mechanics of the following century’s Industrial Revolution, is inextricably entwined with that of the manufacture of cannons, and not simply because both men used components made from heavy hunks of iron. A further link can be made, between the thus gun-connected Wilkinson and Watt on the one hand and the clockmaker John Harrison on the other, as it will be remembered that Harrison’s early sea clock trials were made on Royal Naval warships of the day, warships that carried cannon in large numbers. Those cannons were made by English ironmasters, of whom John Wilkinson was among the most prominent and, as it turned out, the most inventive, too. So the story properly begins there, with the making of the kind of large weapons used by Britain’s navy during the mid-eighteenth century, a time when the nation’s sailors and soldiers were being kept exceptionally busy.^*

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