Exactly

by Simon Winchester

  Brunel, a royalist refugee from the very French instability currently so vexing the Lords of the Admiralty—though he had first immigrated to America and become New York’s chief engineer before returning to England to marry—had sized up the mechanics of the block-making problem. He knew the various operations that were necessary to make a finished block—there were at least sixteen of them; a block, simple though it might have looked, was in fact as complex to make as it was essential to employ—and he had roughed out designs for machines that he thought could perform them.* He sought and, in 1801, won a patent: “A New and Useful Machine for Cutting One or More Mortices Forming the Sides of and Cutting the Pin-Hole of the Shells of Blocks, and for Turning and Boring the Shivers, and Fitting and Fixing the Coak Therein.”

  His design was, in more ways than one, revolutionary. He had one machine perform two separate functions—a circular saw, for example, could perform the duties of a mortice cutter as well. He had the surplus motion of one machine drive its neighbor, maintaining a kind of mechanical lockstep. The necessary coordination of the machines one with the other required that the work each machine performed be accomplished with the greatest precision, for a wrong dimension passed into the system by one wrongly set machine would act much as a computer virus does today, amplifying and worsening by the minute, ultimately infecting the entire system, and forcing it to shut own. And rebooting a system of enormous iron-made steam-powered machines with flailing arms and whirling straps and thundering flywheels is not just a matter of pressing a button and waiting half a minute.

  Given the complexity of the system he had sold to the navy, it was essential only for Brunel to find an engineer who would and could construct such a set of never-before-made machines, and ensure that they were capable of the repetitious making, with great precision, of the scores of thousands of the wooden pulley blocks the navy so keenly needed.

  This is where Henry Maudslay’s window comes in. An old friend of Brunel’s from his French days, another migrant, named M. de Bacquancourt, happened to pass by the Maudslay workshop on Margaret Street and saw, prominent in the bow window, the famed five-foot-long brass screw that Maudslay himself had made on his lathe. The Frenchman went inside, spoke to some of the eighty employees in the machine shop, and then to the principal himself, and came away firm in the belief that if one man in England could do the work Brunel needed, here he was.

  So Bacquancourt told Brunel, and Brunel met Maudslay out at Woolwich. As part of the interview, Brunel then showed the youngster an engineering drawing of one of his proposed machines—whereupon Maudslay, who was able to read drawings in the same way that musicians can read sheet music with the facility that others read books, recognized it in an instant as a means of making blocks. Models of the proposed engines were constructed to show the Admiralty just what was envisioned, and Maudslay set to work, with a formal government commission.

  He was to devise and build, as specified in Brunel’s drawings, the first precision-made machines in the world that would be established for the sole purpose of manufacturing items. In this case it was pulley blocks, but the items could just as well have been guns, or clocks, or, in time to come, cotton gins or motorcars—en masse.

  The project took him six years. The navy built an enormous brick structure in its dockyard at Portsmouth to accommodate the armada of engines they knew was coming. And one by one, first from his workshop back up on London’s Margaret Street and then, as the company expanded, from a site in Lambeth, south of the River Thames, Maudslay’s epoch-making machines started to arrive.

  There would be forty-three of them in total, each performing one or another of the sixteen separate tasks that transformed a felled elm tree into a pulley block to be sent to the naval warehouse. Each machine was built of iron, to keep it solid and sturdy and able to perform its allotted task with the kind of accuracy the navy contract demanded. So there were machines that sawed wood, that clamped wood, that morticed wood, that drilled holes and tinned pins of iron and polished surfaces and grooved and trimmed and scored and otherwise shaped and smoothed the blocks’ way to completion. A whole new vocabulary was suddenly born: there were ratchets and cams, shafts and shapers, bevels and worm gears, formers and crown wheels, coaxial drills and burnishing engines.

  And all inside the Block Mills, as the structure was named in 1808, which was soon set to thundering activity. Each of Maudslay’s machines was sent power by ever-rotating and flapping leather belts, which themselves were spinning by their connection to long iron axles mounted to the ceiling and that, in turn, were set eventually rotating by an enormous thirty-two-horsepower Boulton and Watt steam engine that roared and steamed and smoked outside the building, in its own noisy and dangerous three-story lair.

  The Block Mills still stand as testament to many things, most famously to the sheer perfection of each and every one of the hand-built iron machines housed inside. So well were they made—they were masterpieces, most modern engineers agree—that most were still working a century and a half later; the Royal Navy made its last pulley blocks in 1965. And the fact that many of the parts—the iron pins, for example—were all made by Maudslay and his workers to exactly the same dimensions meant that they were interchangeable, which had implications for the future of manufacturing more generally—as we shall soon see, when the concept of interchangeability was recognized by a future American president.

  But the Block Mills are famous for another reason, one with profound social consequences. It was the first factory in the world to have been run entirely from the output of a steam engine. True, earlier machines had been driven by water, and so the concept of mechanization itself was not entirely new. But the scale and the might of what had been built in Portsmouth were different, and stemmed from a source of power not dependent on season or weather or on any external whim. Providing there was coal and water, and an engine made to specifications demanding of the greatest precision, the factory powered by it would run.

  The saws and the morticing devices and the drills of the future would thus be powered by engines. These engines would (both here in Portsmouth and then very soon thereafter in a thousand other factories elsewhere, making other things by other means) no longer be turned and powered and manipulated by men. The workers who in their various wood shops had hitherto cut and assembled and finished the navy’s pulley blocks had now become the first victims of machinery’s cool indifference. Where more than a hundred skilled craftsmen had once worked, and had filled, just, the navy’s insatiable appetite, now this thundering factory could feed it with ease, without ever breaking a sweat: the Portsmouth Block Mills would turn out the required one hundred thirty thousand blocks each year, one finished block every minute of every working day, and yet it required a crew of just ten men to operate it.

  Precision had created its first casualties. For these were men who needed no special skills. They did no more than feed logs into the slicing machine hoppers and, eventually, take the finished blocks away and stack them inside the storehouses; or else they took their oilcans and their bunches of cotton waste and set to greasing and lubricating and polishing and keeping a weather eye on the clanging and clattering maelstrom of black-and-green and brass-trimmed behemoths, all endlessly mocking them, by revolving and spinning and belching and rocking and lifting and splitting and sawing and drilling, an immense orchestra of machinery that was crammed into the massive new building.

  The social consequences were immediate. On the plus side of the ledger, the machines were precise; the machines did accurate work. The Lords of the Admiralty declared themselves content. Brunel received a check for the money saved in one year: £17,093. Maudslay received £12,000 and the acclaim of the public and of the engineering fraternity and became generally regarded as one of the most important figures in the early days of precision engineering and one of the prime movers of the Industrial Revolution. The Royal Navy shipbuilding program would now go ahead as planned, and with the new squadrons and flotillas and fleets tha
t were able to be created so swiftly, the British saw to it that the wars with France were duly ended, and to Britain’s advantage.

  Napoleon* was finally defeated, and was shipped off to Saint Helena in exile, traveling aboard a seventy-four-gun third-rate ship of the line, the HMS Northumberland, with as escort the smaller sixth-rate twenty-gun HMS Myrmidon. The rigging and other rope work of these two vessels were secured with about sixteen hundred wooden pulley blocks, almost all of them made in the Portsmouth Block Mills, sawed and drilled and milled with Henry Maudslay’s iron engines, all operating under the supervision of ten unskilled navy contract workers.

  Still, the ledger had two sides, and on the minus side, a hundred skilled Portsmouth men had been thrown out of work. One imagines that over the days and weeks after they were handed their final pay and told to go, they and their families wondered just why this had happened, why it was that as the need for products demonstrably increased, the need for workers to construct these products began to shrink swiftly away. To this scattering of Portsmouth men, and to those who relied upon these men for security and sustenance, a sum total rather too few for any serious political consideration, the arrival of precision was not altogether welcome. It seemed to benefit those with power; it was a troubling puzzlement to those without.

  There was a social consequence, a reaction, although the best known, mainly because of its intermittent and spectacular violence, took place some hundreds of miles to the north of Portsmouth and was specifically involved in another industry altogether. Luddism, as it is known today, was a short-lived backlash—it started in the northern Midlands in 1811—against the mechanization of the textile industry, with stocking frames being destroyed and mobs of masked men breaking factories to stop the production of lace and other fine fabrics. The government of the day* was spooked, and briefly introduced the death penalty for anyone convicted of frame breaking; some seventy Luddites were hanged, though usually for breach of other laws against riot and criminal damage.

  By 1816, the steam† had gone out of the rioters, and movement generally subsided. It never entirely died, though, and the word Luddite (from the movement’s presumed leader, Ned Ludd) remains very much in today’s lexicon, mainly as a pejorative term for anyone who resists the siren song of technology. That it does so serves as a reminder that, from its very beginnings, the world of precision-based engineering had social implications that were neither necessarily accepted nor welcomed by all. It had its critics and its Cassandras then; it has them still today, as we shall see.

  Henry Maudslay was by no means done with inventing. Once his forty-three block-making machines were all thrumming along merrily down in Portsmouth, once his contract with the navy had been completed, once his reputation (“the creator of the industrial age”) was secure, he came up with two further contributions to the universe of intricacy and perfection. One of them was a concept, the other a device. Both are essentials, even at this remove of two centuries, the concept most especially so.

  It involves the notion of flatness. It involves the notion that a surface may be created that is, as the Oxford English Dictionary has it, “without curvature, indentation or protuberance.” It involves the creation of a base from which all precise measurement and manufacture can be originated. For, as Maudslay realized, a machine tool can make an accurate machine only if the surface on which the tool is mounted is perfectly flat, is perfectly plane, exactly level, its geometry entirely exact.

  An engineer’s need for a standard plane surface is much the same as a navigator’s need for a precise timekeeper, as John Harrison’s, or a surveyor’s need for a precise meridian, such as that drawn in Ohio in 1786 to start the proper mapping of the central United States. The more prosaic matter of the making of a perfectly flat surface, a critical part of the machine-made world, required only a little ingenuity and a sudden leap of intuition—both these gifts combining in the late eighteenth century in the workshop of Henry Maudslay.

  The process is simplicity itself, and the logic behind it flawless. The Oxford English Dictionary illustrates it nicely with a quotation from the James Smith classic Panorama of Science and Art, first published in 1815, that “to grind one surface perfectly flat, it is … necessary to grind three at the same time.” While it has to be assumed that this basic principle had been known for centuries, it is commonly believed that Henry Maudslay was the first to put it into practice, and create thereby an engineering standard that exists to this day.

  So accurate was Henry Maudslay’s bench micrometer that it was nicknamed “the Lord Chancellor,” as no one would dare have argued with it.

  Photograph courtesy of the Science Museum Group Collection.

  Three is the crucial number. You can take two steel plates and grind them and smooth them to what is believed to be perfect flatness—and then, by smearing each with a colored paste and rubbing the two surfaces together and seeing where the color rubs off and where it doesn’t, as at a dentist’s, an engineer can compare the flatness of one plate with that of the other. Yet this is a less than wholly useful comparison—there is no guarantee that they will both be perfectly flat, because the errors in one plate can be accommodated by errors in the other. Let us say that one plate is slightly convex, that it bulges out by a millimeter or so in its middle. It may well be that the other plate is concave in just the same place, and that the two plates then fit together neatly—giving the impression that the flatness of one is the same as the flatness of the other. Only by testing both these planes against a third, and by performing more grinding and planing and smoothing to remove all the high spots, can absolute flatness (with the kind of near-magical properties displayed by my father’s gauge blocks) be certain.

  AND THEN THERE was the measuring machine, the micrometer. Henry Maudslay is generally also credited with making the first of this kind of instrument, most particularly one that had the look and feel of a modern device. In fairness, it must be said that a seventeenth-century astronomer, William Gascoigne, had already built a very different-looking instrument that did much the same thing. He had embedded a pair of calipers in the eyeglass of a telescope. With a fine-threaded screw, the user was able to close the needles around each side of the image of the celestial body (the moon, most often) as it appeared in the eyepiece. A quick calculation, involving the pitch of the screw in inches, the number of turns needed for the caliper to fully enclose the object, and the exact focal length of the telescope lens, would enable the viewer to work out the “size” of the moon in seconds of arc.

  A bench micrometer, on the other hand, would measure the actual dimension of a physical object—which was exactly what Maudslay and his colleagues would need to do, time and again. They needed to be sure the components of the machines they were constructing would all fit together, would be made with exact tolerances, would be precise for each machine and accurate to the design standard.

  As with Gascoigne’s invention of a century before, the bench micrometer’s measurement was based on the use of a long and skillfully made screw. It employed the basic principle of a lathe, except that instead of having a slide rest with cutting or boring tools mounted upon it, there would be two perfectly flat blocks, one attached to the headstock, the other to the tailstock, and with the gap between them opened or closed with a turn of the leadscrew.

  And the width of that gap, and of any object that fitted snugly between the two flat blocks, could be measured—the more precisely if the leadscrew was itself made with consistency along its length, and the more accurately if the leadscrew was very finely cut and could advance the blocks toward one another slowly, in the tiniest increments of measurable movement.

  Maudslay tested his own five-foot brass screw with his new micrometer and found it wanting: in some places, it had fifty threads to the inch; in others, fifty-one; elsewhere, forty-nine. Overall, the variations canceled one another out, and so it was useful as a leadscrew, but because Maudslay was so obsessive a perfectionist, he cut and recut it scores of times unt
il, finally, it was deemed to be wholly without error, good and consistent all along its massive length.

  The micrometer that performed all these measurements turned out to be so accurate and consistent that someone—Maudslay himself, perhaps, or one of his small army of employees—gave it a name: the Lord Chancellor. It was pure nineteenth-century drollery: no one would ever dare argue with or challenge the Lord Chancellor. It was a drily amusing way to suggest that Maudslay’s was the last word in precision: this invention of his could measure down to one one-thousandth of an inch and, according to some, maybe even one ten-thousandth of an inch: to a tolerance of 0.0001.

  In fact, with the device’s newly consistent leadscrew sporting one hundred threads per inch, numbers hitherto undreamed of could be achieved. Indeed, according to the ever-enthusiastic colleague and engineer-writer James Nasmyth, who so worshipped Maudslay that he eventually wrote a rather too admiring biography, the fabled micrometer could probably measure with accuracy down to one one-millionth of an inch. This was a bit of a stretch. A more dispassionate analysis performed much later by the Science Museum in London goes no further than the claim of one ten-thousandth.

  And this was only 1805. Things made and measured were only going to become more precise in the years ahead, and they would do so to a degree that Maudslay (for whom an abstraction, the ideal of precision, was perhaps the greatest of his inventions) and his colleagues could never have imagined. Yet there was some hesitancy. A short-lived hostility to machines—which is at least a part of what the Luddite movement represented, a mood of suspicion, of skepticism—briefly gave pause to some engineers and their customers.

  And then there was that other familiar human failing, greed. It was greed that in the early part of the nineteenth century played some havoc with precision’s halting beginnings across the water, to where this story now is transferred, in America.