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

aspects of the craft, and thus qualified, he was sent in 1940 to the British embassy in Washington, DC (in secret, and wearing civilian clothes, as the United States had so far not joined the war). His duties were mainly to liaise with American ammunition makers to create ordnance that would fit into British-issued weapons.

      In 1942, he was given a special mission: to work out just why some American antitank ammunition was jamming, randomly, when fired from British guns. He promptly took a train to the manufacturers in Detroit and spent weeks at the factory painstakingly measuring batches of ammunition, finding, to his chagrin, that every single round fitted perfectly in the weapon for which it was destined, meeting the specifications with absolute precision. The problem, he told his superiors back in London, did not lie with the plant. So London told him to follow the ammunition all the way to where the commanders were experiencing the vexing misfires, and that was in the battlefields of the North African desert.

      Mr. Povey, lugging along his giant leather case of measuring equipment, promptly lit out for the East Coast. He first traveled on a variety of ammunition trains, passing slowly across the mountains and rivers of eastern America, all the way to Philadelphia, whence the ordnance was to be shipped. Each day, he measured the shells, and found that they and their casings retained their design integrity perfectly, fitting the gun barrels just as well at each of the railway depots as they had when they left the production lines. Then he boarded the cargo ship.

      It turned into something of a testing journey: the vessel broke down, was abandoned by its convoy and its destroyer escort, became frighteningly vulnerable to attack by U-boats, and was trapped in a mid-ocean storm that left all of the crew wretchedly seasick. But, as it happened, it was this deeply testing environment that allowed Mr. Povey finally to solve the puzzle.

      For it turned out that the severe rocking of the ship damaged some of the shells. They were stacked in crates deep in the ship’s hold. As the vessel rocked and heeled in the storm, those crates on the outer edges of the stacks, and only those, would crash into the sides of the ship. If they hit repeatedly, and if when they hit they were configured in such a way that the tip of the ammunition struck the wall of the hold, the whole of the metal projectile at the front end of each shell—the bullet, to put it simply—would be shoved backward, by perhaps no more than the tiniest fraction of an inch, into its brass cartridge case. This collision, if repeated many times, caused the cartridge case to distort, its lip to swell up, very slightly, by a near-invisible amount that was measurable only by the more sensitive of Povey’s collection of micrometers and gauges.

      The shells that endured this beating—and they would be randomly distributed, for once the ship had docked and the stevedores had unloaded the crates and the ammunition had been broken down and sent out to the various regiments, no one knew what order the shells would be in—would, as a result, not fit into the gun barrels out on the battlefield. There would, in consequence, be (and entirely randomly) a spate of misfires of the guns.

      It was an elegant diagnosis, with a simple recommended cure: it was necessary only for the factory back in Detroit to reinforce the cardboard and wood of the ammunition crates and—presto!—the shell casings would all emerge from the ship unbruised and undistorted, and the jamming problem with the antitank rifles would be solved.

      Povey telegraphed his news and his suggestion back to London, was immediately declared a hero, and then, in classic army style, was equally immediately forgotten about, in the desert, without orders, but with, as he had been away from his office in Washington for so long, a considerable amount of back pay.

      Hot work in the Sahara it must have been, for at this point the story wavers a little: Mr. Povey Sr. seems to have gone on some kind of long-drawn-out desert bender. But after enjoying the sunshine for an indecent number of weeks, he decided that he did in fact need to return to America, so he bribed his way back there with bottles of Scotch whisky. It took him eleven bottles of Johnnie Walker to get from Cairo (via a temporary aerodrome in no less exotic a wartime stopover than Timbuktu) to Miami, after which it was but a short and easy hop up to Washington.

      There he found dismaying news. It turned out that he had been away in Africa for so long without any communication that he had been declared missing and presumed dead. His mess privileges had been revoked, his cupboard closed, and all his clothes altered to fit a much smaller man.

      It took a while for this discomfiting mess to be sorted out, and when eventually everything was more or less back to normal, he discovered that his entire ordnance unit had been transferred to Philadelphia—to which he promptly went as well.

      There he met and fell in love with the unit’s American secretary. The pair got married, and Mr. Povey, never apparently practicing the Hinduism that had been engraved on his army dog tag, remained blamelessly in the United States for the rest of his days.

      And, as my correspondent then wrote, with a flourish, “the lady in question was my mother, and so I exist—and I exist entirely because of precision.” This is why, he then added, “you must write this book.”

      BEFORE WE DELVE too deeply into its history, two particular aspects of precision need to be addressed. First, its ubiquity in the contemporary conversation—the fact that precision is an integral, unchallenged, and seemingly essential component of our modern social, mercantile, scientific, mechanical, and intellectual landscapes. It pervades our lives entirely, comprehensively, wholly. Yet, the second thing to note—and it is a simple irony—is that most of us whose lives are peppered and larded and salted and perfumed with precision are not, when we come to think about it, entirely sure what precision is, what it means, or how it differs from similar-sounding concepts—accuracy most obviously, or its lexical kissing cousins of perfection and exactitude and of being just right, exactly!

      Precision’s omnipresence is the simplest to illustrate.

      A cursory look around makes the point. Consider, for example, the magazines on your coffee table, in particular the advertising pages. In a scant few minutes you could, for instance, construct from them a rough timetable for enjoying a precision-filled day.

      You would begin your morning by first using a Colgate Precision Toothbrush; if you were clever enough to keep up with Gillette’s many product lines, you could enjoy less “tug and pull” on your cheek and chin by shaving with the “five precision blades” in its new Fusion5 ProShield Chill cartridge, and then tidying up your goatee and mustache with a Braun Precision Trimmer. Before the first meeting with a new acquaintance, be sure to have any former-girlfriend-related body art painlessly removed from your biceps with an advertised machine that offers patented “precision laser tattoo removal.” Once thus purified and presentable, serenade your new girlfriend by playing her a tune on a Fender Precision bass guitar; maybe take her for a safe wintertime spin after fitting your car with a new set of guaranteed-in-writing Firestone Precision radial snow tires; impress her with your driving skills first out on the highway and then at the curb with adroit use of the patented Volkswagen Precision parking-assist technology; take her upstairs and listen to soft music played on a Scott Precision radio (a device that will add “laurels of magnificent dignity to those of the world-record achievements” of the Chicago-based Scott Transformer Company—not all the magazines on an average coffee table are necessarily current). Then, if the snow has eased, prepare dinner in the back garden with a Big Green Egg outdoor stove equipped with “precision temperature control”; gaze dreamily over nearby fields newly sown with Johnson Precision corn; and finally, take comfort from the knowledge that if, after the stresses of the evening, you awake hungover or unwell, you can take advantage of the precision medicine that is newly available at NewYork-Presbyterian Hospital.

      It took no time at all to tease out these particular examples from one randomly selected coffee-table pile. There are all too many others. I see, for instance, that the English novelist Hilary Mantel recently described the future British queen, née Kate Middleton, as being so outwardly perfect as to appear “precision-made, machine-made.” This went down well with neither royalists nor engineers, as what is perfect about the Duchess of Cambridge, and indeed with any human being, is the very imprecision that is necessarily endowed by genes and upbringing.

      Precision appears in pejorative form, as here. It is also enshrined elsewhere and everywhere in the names