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

powder paper cartridges, a pouch full of roundball ammunition. But the regimental armorer had told him it would be at least three days before they could forge a new trigger for him, and that he had best do all he could with his bayonet, which he had sharpened that very night, before the sun rose. Otherwise, the armorer had said with a grin, just hit the enemy hard with the gun’s oakwood stock—it should give him a black eye at the very least.

      That turned out not to be at all funny. The British were close by, on the left bank of the East Branch of the Potomac, when their artillery opened up later that morning, first with a deafening volley of Congreve rockets, a terrifying technique they had learned from fighting in India. It was at that moment, as massive divots of torn earth and stones clattered down around him, that the young man decided his life was more valuable than the winning of this particular battle, and that if the army couldn’t be bothered to fix his musket, then he was going to run. So he turned and plunged into the high corn, heading back home to Baltimore.

      He soon understood he was not alone. Through the stands of corn he could see at least five, ten, dozens of other men who were doing just the same, streaming away from the fight. Some he knew, young lads from Annapolis and the Washington Navy Yard and the Light Dragoons, all of them apparently believing that the defense of Bladensburg was hopeless. He ran and ran and ran, and they ran, too, and all of them were still running when they crossed the line marking the District of Columbia, and they continued running, loping breathlessly in many cases, when, half an hour later, there rose before him some of the mighty structures of his capital, great buildings from where his country’s government was dealing with the incomprehensible vastness of America.

      He slowed to a walk. He felt he was safe now. His city was not. Before the night was out, the pursuing British troops had sacked it, more or less entirely. He found out later that the British told some of the city folk they were acting so cruelly because American forces some weeks before had had the temerity to wreck and damage buildings in the city of York, in Upper Canada. So here they burned out of revenge. They torched the half-built Capitol. They gutted the Library of Congress, and its three thousand books, and they sacked the House of Representatives. British officers dined that evening on the food Madison had been planning to eat at his Presidential Mansion, and then, after wreaking that domestic indignity, they burned his house down, too, until a ferocious rainstorm—some say a tornado—blew in and doused the flames.

      The date, August 24, 1814, would be remembered for centuries to come. The Battle of Bladensburg, the last stand before the Burning of Washington and Burning of the White House, that most potent of incendiary symbols, had been one of the most infamous routs in all American history, a shameful and sorry episode indeed. The imagined account of this one soldier at war was typical of what happened that day, with battle lines being broken and troops running away in panic before the advancing enemy.

      There were many reasons for the defeat, and they would be debated by clubbable old soldiers for many years. Inept leadership, ill-preparedness, insufficient numbers—the usual excuses for substantial loss have all been offered down the years. Yet one, a most notorious shortcoming of the American forces (who, after all, had fought little in the years since the War of Independence), was that the muskets with which their infantrymen had been equipped were notoriously unreliable. More important, when they failed, they were fiendishly difficult to repair.

      When any part of a gun failed, another part had to be handmade by an army blacksmith, a process that, with an inevitable backlog caused by other failures, could take days. As a soldier, you then went into battle without an effective gun, or waited for someone to die and took his, or did your impotent best with your bayonet, or else, as the young man of Sterrett’s regiment did, you ran.

      The problem with gun supply was twofold. The U.S. Army’s standard long gun of the time was a smooth-bored flintlock musket based on a model first built in France and known as the Charleville. The first of these weapons had been imported into the newly independent United States directly from France; they were then manufactured by agreement at the newly built U.S. government armory in Springfield, Massachusetts. Both models had worked adequately, though all flintlocks had misfiring problems and suffered all the simple physical shortcomings that afflicted handmade weapons that were pressed into continuous service—they overheated; their barrels became clogged with powder residue; or the metal parts broke, snapped, got bent, unscrewed, or were simply lost.

      This led to the second problem—because once a gun had been physically damaged in some way, the entire weapon had to be returned to its maker or to a competent gunsmith to be remade or else replaced. It was not possible, incredible though this might seem at the remove of a quarter millennium, simply to identify the broken part and replace it with another from the armory stores. No one had ever thought to make a gun from component parts that were each so precisely constructed that they were identical one with another. Had this step been taken, a broken part could have been replaced, swapped for another, because thanks to the precision of its making, it would have been interchangeable. Break a trigger in battle, and all one would have to do was fall back and get the armorer at the rear of the line to reach into his tin box marked “Triggers” and get another, ease it into place, secure it, and be back on the firing line as a fully armed and effective infantryman within minutes.

      Yet no one had thought of such a thing—except that they had. Thirty years before the humiliating debacle at Bladensburg, a new manufacturing process had been created that, had it been in operation in the United States in 1814, might well have staved off a defeat occasioned by the failure of the soldiers’ guns. The new thinking about the principles of gun making, thinking that, if put into practice, might perhaps have kept Washington from being put to the torch, began not in Washington, nor in the two federal armories at Springfield and down at Harpers Ferry, Virginia, nor in most of one of the stripling gun-making factories that had sprung up during and immediately after the Revolutionary War. The idea was actually born three thousand miles away, in Paris.

      BACK IN THE late eighteenth century, no one spoke about “the dark side.” The phrase is modern, too new for the OED. In almost all the interviews for this book, about the ultrahigh-precision instruments, devices, and experiments that indicate where the precision that originates here is likely to be going, engineers and scientists referred frequently, and usually obliquely, to what “the dark side” might be doing. Once in a while, I would meet someone who admitted to having security clearance, and would thus in theory be able to discuss in greater detail what this experiment was leading to, how this device might be constructed, what the future of such-and-such a project might be—but he would invariably grin and say that, no, he couldn’t discuss what “the dark side” was doing.

      “The dark side” is the American military, and in terms of new weaponry or research into the unimaginably precise, that tends to mean the U.S. Air Force. Area 51 is the dark side. DARPA is the dark side. The NSA is the dark side. The role of the dark side in this story is immense, but in today’s world, it is mainly to be only alluded to.

      Lewis Mumford, the historian and philosopher of technology, was one of the earliest to recognize the major role played by the military in the advancement of technology, in the dissemination of precision-based standardization, in the making of innumerable copies of the same and usually deadly thing, all iterations of which must be identical to the tiniest measure, in nanometers or better. The stories that follow, in which standardization and precision-based manufacturing are shown to become crucial ambitions of armies on both sides of the Atlantic, serve both to confirm Mumford’s prescience and to underline the role that the military plays in the evolution of precision. The examples from the early days of the science are of course far from secret; those from today, and that might otherwise be described in full to illustrate today’s very much more precise and precision-obsessed world, are among the most secure and confidential topics of research on the planet—kept in permanent shadow, as the dark side necessarily has to be.

      IT WAS IN the French capital in 1785 that the idea of producing interchangeable parts for guns was first properly realized, and the precision manufacturing processes that allowed for it were ordered to be first put into operation. Still, it is reasonable to ask why, if the process was dreamed up in 1785, was it not being applied to the American musketry in official use in 1814, twenty-nine years later? Men were running, battles were being lost, great