IN 1789, JOSEPH Bramah cut an anxious figure. The political situation across the Channel was causing an influx of terrified French refugees, most of them bound for London, where the more nervously xenophobic residents of England’s capital suddenly started to demand ever more security for their homes and businesses. Bramah, with his patent-protected monopoly, was caught in a bind: he alone could make his locks, but neither he nor any engineer he could find had the ability to make them in sufficient numbers at a low enough price. Most men who called themselves engineers may have been adept at the cruder crafts—at thumping ingots of heat-softened iron with heavy hammers and then working to shape the crudely formed results with anvils, chisels, and, most especially, files—but few had a great feel for delicacy, for the construction of (and the word had only recently been adopted) mechanisms.
Change was coming, though. Workers at the smithies of eighteenth-century London were a close-knit group, and word eventually did reach Bramah that a particular youngster at Woolwich was startlingly unlike his older peers and, rather than bashing hunks of iron, was apparently crafting metal pieces of an unusual, fastidious daintiness. Bramah interviewed the teenage Maudslay. Though taking to him immediately, the former was only too well aware that the custom was for any would-be entrant to the trade to serve a seven-year apprenticeship. However, commercial need trumped custom: with would-be patrons beating down his door back on Piccadilly, Bramah had no time to spare for the niceties, decided to take a chance, and hired the youngster on the spot. His decision was to change history.
Henry Maudslay turned out to be a transformative figure. First of all, he solved Bramah’s supply problems in an inkling—but not by the conventional means of hiring workers who would make the locks one by one through the means of their own craftsmanship. Instead, and just like John Wilkinson two hundred miles west and thirteen years earlier, Maudslay created a machine to make them. He made a machine tool: in other words, a machine to make a machine (or, in this case, a mechanism). He built a whole family of machine tools, in fact, that would each make, or help to make, the various parts of the fantastically complicated locks Joseph Bramah had designed. They would make the parts, they would make them fast and well and cheaply, and they would make them without the errors that handcrafting and the use of hand tools inevitably bring in their train. The machines that Maudslay made would, in other words, make the necessary parts with precision.
Three of his lock-making devices can be seen today in the Science Museum in London. One is a saw that cut the slots in the barrels; another—perhaps less a machine tool than a means of ensuring that production went along at high speed, with every part made exactly the same—is a quick-grip, quick-release vise, a fixture that would hold the bolt steady while it was milled by a series of cutters mounted on a lathe; and the third is a particularly clever device, powered by a foot-operated treadle, that would wind the lock’s internal springs and hold them under tension as they were positioned and secured in place until the outer cover, a well-shined brass plate with the flamboyant signatures of the Bramah Lock Company of 124 Piccadilly, London, inscribed on its face, was bolted on to finish the job.
A fourth and, some would argue, most supremely important machine tool component also started to make its widespread appearance around this time. It would shortly become an integral part of the lathe, a turning device that, much like a potter’s wheel, has been a mechanical aid to the betterment of human life since its invention in pharaonic Egypt. Lathes evolved very slowly indeed over the centuries. Perhaps the biggest improvement came in the sixteenth century, with the concept of the leadscrew. This was a long and (most often, in early times) wooden screw that was mounted under the main frame of the lathe and could be turned by hand to advance the movable end of the lathe toward or away from the fixed end. It could do so with a degree of precision; one turn of the handle might advance the movable part of the lathe by an inch, say, depending on the pitch of the leadscrew. It gave wood turners working on a lathe a much greater degree of control, and allowed them to produce things (chair legs, chess pieces, handles) of great decorative beauty, symmetric loveliness, and baroque complexity.
Henry Maudslay then improved the lathe itself by many orders of magnitude—first by making it of iron, forging its structure stoutly and heavily, and at a stroke allowing it not merely to machine wooden items, but also to create symmetry out of shapeless billets of hard metal, which the flimsy lathes of old were incapable of doing. This alone might have been sufficient for us to remember the man, but then Maudslay employed one further component on his working lathes, a component whose origins are debated still, however, with the tenor of the debate pointing to an endless argument that complicates the historiography of precision and precision engineering.
Henry Maudslay, once a “tall, comely fellow,” machined the innards of Bramah’s locks and went on to become the founding father of precision toolmaking, mass production, and the key engineering concept of achieving perfect flatness.
Specifically, the device in question mounted on Maudslay’s lathes is known as a slide rest, a part that is massive, strongly made, and securely held but movable by way of screws, and is intended to hold any and all of the cutting tools. It is filled with gears that allow for the adjustment of the tool or tools to tiny fractions of an inch, to permit the exact machining of the parts to be cut. The slide rest is necessarily placed between the lathe’s headstock (which incorporates the motor and the mandrel that spins the workpiece around) and the tailstock (which keeps the other end of the workpiece secure). The leadscrew—Maudslay’s was made of metal, not wood, and with threads much closer together and with a more delicate pitch than was possible for a wooden version—advances the workpiece. The tools held on the slide rest can then be moved across the path of travel dictated by the leadscrew, thereby allowing the tools to make holes in the workpiece, or to chamfer it or (in due course, once milling had been invented, a process related in the next chapter) mill it or otherwise shape it to the degree that the lathe operator demands. So the leadscrew moves the workpiece longitudinally, and the slide rest that holds the tools that cut or chamfer or make holes in the workpiece moves transversely, or in all sorts of directions that are across the path made by the leadscrew.
Metal pieces can be machined into a range of shapes and sizes and configurations, and provided that the settings of the leadscrew and the slide rest are the same for every procedure, and the lathe operator can record these positions and make certain they are the same, time after time, then every machined piece will be the same—will look the same, measure the same, weigh the same (if of the same density of metal) as every other. The pieces are all replicable. They are, crucially, interchangeable. If the machined pieces are to be the parts of a further machine—if they are gearwheels, say, or triggers, or handgrips, or barrels—then they will be interchangeable parts, the ultimate cornerstone components of modern manufacturing.
Of equally fundamental importance, a lathe so abundantly equipped as Maudslay’s was also able to make that most essential component of the industrialized world, the screw.
Over the centuries, there were many incremental advances in screw making, as we shall see, but it was Henry Maudslay (once he had invented or mastered or improved or in some other manner become intimately associated with the slide rest on his lathe) who then devised a means of cutting metal screws, efficiently, precisely, and fast. Much as Bramah had a lock in his workshop window on Piccadilly, for reasons of pride as much as for his famous challenge, so Maudslay, Sons and Field placed in the bow window of the firm’s first little workshop, on Margaret Street in Marylebone, a single item of which the principal was most proud—and that was a five-foot-long, exactly made, and perfectly straight industrial screw made of brass.
Technically, Maudslay was not the first to perfect a screw-making lathe. Twenty-five years earlier, in 1775, Jesse Ramsden, a scientific instrument maker in Yorkshire who was funded by the same Board of Longitude for which the clockmaker John Harriso
n had labored, and who was not allowed to patent his invention, had made a small and exquisite screw-cutting lathe. This could cut tiny screws with as many as one hundred twenty-five turns to the inch—meaning it would take one hundred twenty-five turns to advance the screw by one inch—and so would allow the tiniest adjustments to any device to which the screw was harnessed. But Ramsden’s was effectively a one-off machine, as delicate as a watch, meant for work with telescopes and navigational instruments, and in no way destined for the making of large-scale devices made of much metal and that could work at great speed and maintain accuracy and be durable. What Maudslay had done with his fully equipped lathe was to create an engine that, in the words of one historian, would become “the mother tool of the industrial age.”
Moreover, with a screw that was made using his slide rest and his technique, and with a lathe constructed of iron and not with the wooden frame he and Bramah had used initially, he could machine things to a standard of tolerance of one in one ten-thousandth of an inch. Precision was being born before all London’s eyes.
So, whoever did invent the slide rest can take the credit for the later precise manufacture of countless components of every conceivable size and shape and relevance to a million and one machined objects. The slide rest would allow for the making of myriad items, from door hinges to jet engines to cylinder blocks, pistons, and the deadly plutonium cores of atomic bombs—as well as, of course, the screw.
But just who did invent it? Not a few say Henry Maudslay, and that he did so in Joseph Bramah’s “secret workplace [which] contained several curious machines . . . constructed by Mr. Maudslay with his own hands.” Others say it was Bramah. Still others refute the idea of Maudslay’s involvement entirely, saying definitively that he did not invent it, nor ever claimed to have done so. Encyclopedias say the first slide rest was actually German, having been seen illustrated in a manuscript in 1480. Andrey Nartov, the Russian scientist who had the eighteenth-century title of personal craftsman to Tsar Peter the Great, was revered as the greatest teacher of lathe operation in Europe (and taught the methods to the then-king of Prussia) and is said to have made a working slide rest (and taken it to London to show it off) as early as 1718. And just in case the story from St. Petersburg has any doubters, a Frenchman named Jacques de Vaucanson quite provably made one in 1745.
Chris Evans, a professor in North Carolina who has written extensively about the early years of precision engineering, notes the competing claims, and cautions against the “heroic inventor” treatment of the story. Far better to acknowledge, he says, that precision is a child of many parents, that its advances invariably overlap, that there are a great many indeterminate boundaries between the various disciplines to which the word precision can be attached, and that it was, in its early days, a phenomenon that evolved steadily over three centuries of ever-lessening bewilderment. It is, in other words, a story far less precise than its subject.
That being said, Henry Maudslay’s principal legacy is a wholly memorable one, for other inventions and involvements followed his association with Joseph Bramah, from whose employ he left, in a huff, after his request for a raise—he was making thirty shillings a week in 1797—was turned down too curtly for his taste.
MAUDSLAY PROMPTLY PROCEEDED to free himself from the circumscribed world of West London lock making, and he entered—one might say, he inaugurated—the very different world of mass production. He created in the process the wherewithal for making, in truly massive numbers, a vital component for British sailing ships. He built the wondrously complicated machines that would, for the next one hundred fifty years, make ships’ pulley blocks, the essential parts of a sailing ship’s rigging that helped give the Royal Navy its ability to travel, police, and, for a while, rule the world’s oceans.
This all came about in a moment of the happiest chance, and just as with Bramah and the lock in Piccadilly, it involved a shopwindow (Henry Maudslay’s) and the proud public showroom display of the five-foot-long brass screw Maudslay had made on his lathe and which he had placed there, center stage, as an advertisement of his skills. Soon after he set up the screw display, so naval legend has it, came the serendipitous moment. It involved the two figures who were going to create the pulley block factory, and who vowed to do so properly, to fill an urgent and growing need.
A block-making factory of sorts had already been set up in the southern dock city of Southampton in the mid-eighteenth century, performing some of the sawing and morticing of the wooden parts, but much of the finishing work still had to be done by hand, and in consequence, the supply chain remained unreliable at best. And a reliable supply chain was seen to be vital for England’s survival.
Britain had been at war with France, on and off, for much of the late eighteenth century, and the arrival on the scene of Napoleon Bonaparte in the aftermath of the French Revolution convinced London that her forces needed to be at the ready for much of the early nineteenth century, too. Of the two British fighting forces, the army and the Royal Navy, it was the admirals who took the lion’s share of the war budget, and Britain’s docks were soon bristling with big ships ready to cast off at a moment’s notice to give any French opponents, Napoleon’s especially, a taste of the lash. Shipyards were busy building, dry docks were busy repairing, and the seas from the Channel to the Nile, from the Barbary Coast to Coromandel, were alive with great British men-o’-war, powerful and watchful, ceaselessly on the prowl.
These were, of course, all sailing vessels. Mostly they were enormous craft with wooden hulls and copper-sheathed keels, with three decks ranged with cannon, with enormous masts of Norfolk Island pine supporting equally vast acreages of canvas sailcloth. And all the sail ware of the time were bolts of canvas suspended, supported, and controlled by way of endless miles of rigging, of stays and yards and shrouds and footropes, most of which had to pass through systems of tough wooden pulleys that were known simply to navy men as blocks—pulley blocks, part of a warship’s arrangements known within and beyond the maritime world as block and tackle.
A large ship might have as many as fourteen hundred pulley blocks, which were of varying types and sizes depending on the task required. A block with a single pulley might be all that was needed to allow a sailor to hoist a topsail, say, or move a single spar from one location to another. The lifting of a very heavy object (an anchor, for example) might need an arrangement of six blocks, each with three sheaves, or pulleys, and with a rope passing through all six such that a single sailor might exert a pull of only a few easy pounds in order to lift an anchor weighing half a ton. Block-and-tackle physics, taught still in some good primary schools, shows how even the most rudimentary pulley system can offer the greatest of mechanical advantage, and combines this power with an equally great degree of simplicity and elegance.
Blocks for use on a ship are traditionally exceptionally strong, having to endure years of pounding water, freezing winds, tropical humidity, searing doldrums heat, salt spray, heavy duties, and careless handling by brutish seamen. Back in sailing ship days, they were made principally of elm, with iron plates bolted onto their sides, iron hooks securely attached to their upper and lower ends, and with their sheaves, or pulleys, sandwiched between their cheeks, and around which ropes would be threaded. The sheaves themselves were often made of Lignum vitae, the very same hard and self-lubricating wood that John Harrison used for the gear trains of some of his clocks: most modern blocks have aluminum or steel sheaves and are themselves made of metal, except where the desired look of the boat is old-fashioned, in which case there is much showy brassware and varnished oak.
Hence the early nineteenth-century Royal Navy’s acute concern. An increasingly fractious Napoleonic France lay just twenty miles away across the Channel, and countless maritime problems were demanding Britain’s maritime attentions elsewhere: what principally concerned the admirals was not so much the building of enough ships but the supply of the vital blocks that would allow the sailing ships, to put it bluntly, to sail. The Ad
miralty needed one hundred thirty thousand of them every year, of three principal sizes, and for years past, the complexity of their construction meant that they could be fashioned only by hand. Scores of artisanal woodworkers in and around southern England were originally bent to the task, a supply system that proved notoriously unreliable.
As hostilities at sea became ever more commonplace, as more and more ships were ordered, the drumbeat for a more efficient system became ever louder. The then–inspector general of naval works, Sir Samuel Bentham, finally decided he would act; he would sort things out. And in 1801, Bentham was approached by a figure named Sir Marc Brunel, who said he had in mind a specific scheme for doing so.*
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.
The Perfectionists: How Precision Engineers Created the Modern World Page 7
