The Most Powerful Idea in the World Part 10

The answer was Trevithick's real eureka moment. Gilbert explained that with each stroke,25 the cylinder would lose exactly as much pressure inside as the pressure outside: 14.7 pounds per square inch at sea level. This would obviously be disastrous for a Boulton & Watt separate-condensing engine, which generated only a little more than ten pounds per square inch inside the cylinder; exhausting the condensation would leave it with no pressure at all.

But what if the pressure inside the cylinder could be increased?

In 1800, five years after Joseph Stacey Sampson had brought Oliver Evans's drawings to Britain, and three years after Davies Gilbert had shown that an engine operating at 60 psi would lose only a quarter of its pressure at each stroke, Richard Trevithick introduced his first high-pressure steam engine at the Wheal Hope copper mine. It used almost precisely the same method Evans used for increasing the steam pressure from the boiler. It is not known whether Trevithick saw the Evans design firsthand or-more plausibly-through William Murdock, his neighbor in the town of Redruth for six months in 1797 (and who, despite his employment by the despised firm of Boulton & Watt, was friendly with Trevithick). The sequence of events, however, is persuasive: Sampson carried Evans's drawings to Britain in 1795, to show to "the steam engineers there." The British steam engineer best known to be working on high-pressure steam for locomotion was William Murdock, who was Trevithick's neighbor when the Cornishman asked Davies Gilbert to give a scientist's opinion on what was, in essence, the practicality of Evans's engine.

The Wheal Hope engine showed that a high-pressure engine was practical; a little more than a year later, Trevithick was ready to demonstrate that it was mobile as well. On Christmas Eve 1801, with apparently no warning, Trevithick appeared on the High Street of the town of Camborne aboard a carriage unlike anything anyone had ever seen before. No drawings survive, though a sketch dated a year later shows a four-wheeled flatbed truck with a vertical steam engine set over the front wheels, a twelve-foot-high boiler over the rear, and the driver (wearing what looks like a top hat) set behind. We do have the testimony of one of the blacksmiths who worked on the castings for the machine, "old Stephen Williams": Captain d.i.c.k got up steam,26 out in the high-road, just outside the shop at the Weath. When we get see'd that Captain d.i.c.k was agoing to turn on steam, we jumped up as many as could; maybe seven or eight of us. 'Twas a stiffish hill going from the Weight up to Camborne Beacon, but she went off like a little bird....

When she had gone about a quarter of a mile, there was a roughish piece of road covered with loose stones; she didn't go quite so fast.... She was going faster than I could walk, and went on up the hill about a quarter or half a mile farther, when they turned her and came back again to the shop....

To the spectators at Camborne Hill wrapped up against the cold that Christmas Eve, the vision of a wheeled vehicle moving uphill without being either pushed or pulled must have seemed something like levitation. For millennia, the force driving wheeled vehicles had always been something external to the vehicle, which meant that the primary traction against the roadway was also generated externally: by a horse's hooves, for example. It was by no means obvious that simply turning a wheel would generate enough traction to pull itself-the first bicycles were still decades in the future-and Trevithick apparently spent the week before his experiment hand-cranking the wheels of a model along cobblestone and dirt roads.

Just as startling to the audience lining the half-mile-long High Street, the engine on board the Camborne carriage made its journey belching smoke like something out of myth. Trevithick's engines, having dispensed with a separate condenser, were thereafter known as "puffers" because their steam exhausted directly to the air. The distinctive clouds familiarly a.s.sociated with steam engines* had finally been born.

It didn't survive its own infancy; the engine that Stephen Williams rode up Camborne Hill on Christmas Eve was destroyed before New Year's. Two of Trevithick's drivers27 celebrating the season in a local pub left the boiler unattended, the water boiled away, and the chamber became hot enough to set fire to the engine, and to the shed in which it was housed. Which didn't, in the end, matter all that much. In March 1802, Trevithick, with help from a fellow Cornishman, the scientist Humphry Davy, applied for and received a patent on the new locomotive.

The market for self-propelled steam engines was still a fraction of that for stationary ones, thousands of which were by then pumping water and operating machinery throughout Britain. One of the more avid users was the Coalbrookdale foundry,28 then run by the fourth generation of the Darby family, where the boiler for the Camborne Hill locomotive was built; by the end of 1802, the Darbys had hired Trevithick to build a new stationary engine operating at the seemingly impossible pressure of 145 psi.

Their faith in the Cornishman, and in high-pressure steam, was understandable, but it was controversial. The future of steam power was very clearly at stake, and the established powers of British manufacturing had everything riding on the existing Boulton & Watt low-pressure designs. The Birmingham firm's founders had retired in 1800, but their sons were, if anything, more hostile both to high-pressure steam and to Trevithick than were their fathers. No one knew this better than Cap'n d.i.c.k; after the boiler of a high-pressure engine exploded in Greenwich in September 1803, Trevithick wrote of his belief that "Mr. B. & Watt29 is abot to do mee every engurey in their power for they have don their outemost to repoart the exploseion both in the newspapers and private letters." But though the Boulton & Watt public relations campaign could slow the adoption of high-pressure steam engines-and infuriate Trevithick-it could not stop it. In 1803, a Welsh ironmaster named Samuel Homfray, jealous of his compet.i.tors at Coalbrookdale, invited Trevithick to bring his magic across the Bristol Channel from Cornwall to Wales.

Industrialization in Wales, as in England, had been partly a function of geology, and the great ironworks that had grown up around the town of Merthyr Tydfil in the 1760s were testimony to the generous local supplies of hemat.i.te, limestone, coal, and water, the key ingredients for a furnace-and-forge economy. Just as rich was the supply of ironmongers-four large ironworks, each competing with one another to meet the ever increasing demands of British industry. Competing, and also cooperating: the four ironworks each used the same route to transport their goods to Cardiff and the coast: the twenty-four-mile-long Glamorganshire Ca.n.a.l, which they had built, owned, and, in theory, shared.

They did not, however, share it happily. The owner of the Cyfarthfa ironworks, Richard Crawshay, was also the majority shareholder in the ca.n.a.l, and as a result, barges hauling Cyfarthfa iron were granted preferential treatment. His partners, the owners of the Dowlais, Plymouth, and Penydarren works, were angry enough to build a parallel route for their iron, a horse-drawn railway. One of them was Samuel Homfray of Penydarren, Richard Trevithick's new employer.

Homfray's original objective in hiring the Cornishman seems a bit unformed in retrospect. It is certain that he wanted a new steam engine to run the hammer in Penydarren's forge, but unlikely that he had already thought about replacing the horses pulling his iron-filled carts. For one thing, the existing railway was built for horses rather than locomotives; the rails were set into concrete stones set four feet apart, and had no crossties in between to trip up the horses. Also, the grade was extremely gentle;30 on the way from Merthyr to the wharf at Abercynon, the railway dropped only one foot for every forty-five traveled, putting less strain on the horses both going and returning.

Fig. 8: The Penydarren engine, a replica of which is still on display at the National Maritime Museum at Swansea, was as important in its way as either Newcomen's 1712 Dudley Castle pump, or Watt's 1776 New Willey engine, or even the Stephensons' Rocket. National Railway Museum / Science & Society Picture Library In the event, something provoked Crawshay to bet Homfray five hundred guineas that no steam locomotive could do the job of the horses. To win, Trevithick needed to build an engine capable of hauling ten tons of iron ore from Merthyr to the wharf, nine and a half miles away.

The Penydarren locomotive is practically an encyclopedia of innovation. As protection against explosion, it used one of Trevithick's cleverest inventions, the so-called "fusible plug," a small lead cylinder inserted into a predrilled hole in the wall of the engine's boiler-a hole that, in a properly operating engine, would always be underwater. If, however, the water level in the boiler were to fall low enough to become dangerous, the heat would melt the lead plug, allowing the steam to blow out the fire. The Penydarren engine also incorporated a U-shaped fire tube, a return flue that carried the air heated by the furnace from one end of the boiler and back again, which put at least twice as much surface area in contact with the water. Even more important, it didn't just exhaust the spent steam into the air, but used a chimney that, in Trevithick's own words, "makes the draft much stronger"31-that is, the exhaust steam, hotter than the surrounding atmosphere, rose. By doing so, it pulled more oxygen into the furnace, raising its temperature and increasing the efficiency of the heat engine itself.

In other respects, it was a bit of what a later generation of engineers would call a kludge. Trevithick was obliged to build an engine that would serve Homfray's forge as a steam hammer, whether or not it worked to transport his ore, and it was therefore cobbled together from pieces intended for different functions. Its piston operated like a slide whistle, driving only the two wheels on the engine's left side and conserving momentum with an enormous flywheel set behind them. And, on February 21, 1804, it worked-sort of: ... yesterday we proceeded32 on our journey with the engine, and we carried ten tons of iron in five wagons, and seventy men riding on them the whole of the journey ... the engine, while working, went nearly five miles an hour; there was no water put into the boiler from the time we started until our journey's end ... the coal consumed was two hundredweight.

And, sort of, it didn't. The problem lay less with the locomotive than with the rails, which cracked like twigs. The engine, whose five and a half tons were distributed over only four wheels, and with only two of them driving, put an unantic.i.p.ated lateral strain on the railway. Though Trevithick would try again, on a coal railway in Newcastle in 1805, the rail problem remained unsolved; even in 1808, when Trevithick demonstrated his "Catch-Me-Who-Can" locomotive on a half-mile oval near Gower Street in London for a shilling a head, it was regarded more as a circus act than as any useful industrial advance.

Trevithick's engine, the first driven by high-pressure steam, earned him a considerable claim on the t.i.tle "father of railways," but the birth of steam locomotion was still a decade or so in the future. More important, though less romantic, was another of Trevithick's innovations, one that was nearly as large an improvement over the first high-pressure design as that had been over the Boulton & Watt separate condensing engine-indeed, as big an improvement as Watt's separate condenser was over Newcomen's original atmospheric engine.

For nearly a decade, Trevithick's high-pressure engines had been making significant inroads into the dominant position of Boulton & Watt in Cornwall's mines. By 1812, he determined to displace them once and for all. In a pump built for the Wheal Prosper mine in Cornwall, Trevithick modified his existing high-pressure steam design so that instead of exhausting the condensed steam directly to the atmosphere, as with the Penydarren and Camborne Hill engines, he allowed it to expand into a lower-pressure chamber first. In the new engine, the pressure on the piston came from both the expansive property of high-pressure steam on top of the piston and the atmospheric pressure on the chamber once the steam has been condensed. Steam flowed into the top half of the cylinder and pushed the piston down some distance, at which point a valve closed and the steam expanded to fill the now smaller volume. Trevithick, in comparing an early model to a Boulton & Watt atmospheric engine, discovered that he could produce 40 psi using one-third the coal that the atmospheric engine needed to produce 4 psi. Even more innovative, the new engine's boiler lay horizontally, which allowed the fire tube to run through its middle, heating the water both efficiently and to high pressure. "My predecessors," Trevithick said, "put their boilers in the fire;33 I have put the fire in the boiler." The result, in 1812, was the first really successful "Cornish engine."

It was certainly successful as measured by the still-in-use benchmark of "duty," which measured the pounds of water raised one foot by a bushel of coal. A high-performing Newcomen-style engine typically performed in the neighborhood of 5,000 pounds; Smeaton's many improvements nearly doubled that number-to 9,600 pounds-without changing the basic design, and a 1778 Watt engine, with separate condenser, achieved a duty of 18,900 pounds. By 1812, Trevithick was boasting34 of 40,000 pounds, which is likely an exaggeration, but an objective report of three Cornish engines at the Dolcoath mine reported 21,400, 26,800, and 32,000 pounds in 1814. By 1835, another Cornish engine achieved a duty of 100,000 pounds.

However, efficiency, as measured in duty, was not everything. The price of the Cornish engine's dramatic achievement was that its multiple chambers and valves demanded an unforgiving level of both precision and maintenance. Without either, they were more subject to breakdowns-and to the purchaser of a steam engine trying to make delivery of a scheduled amount of cotton, produce a quant.i.ty of iron, or pump water, it mattered little to have the most efficient steam engine if it was out of commission for two days a week. As a result, it is the last advance in steam power with Trevithick's name attached to it.

Instead, like a homing pigeon, he returned to his origins: precious metals mining. Trevithick became obsessed with reopening the silver mines of Cerro de Pasco in Peru, which had once been among the richest of Spain's possessions in the New World. Trevithick convinced himself that he would be able to make the Peruvian mines profitable once again, and he left Britain planning to do so in October 1816, arriving in February of the following year.

His timing could have been better. By 1817, most of South America was in rebellion against Spain; the month before Trevithick arrived in Peru, the Argentine general Jose de San Martin had crossed the Andes into Chile and was preparing to head north. A month before that, Simon Bolivar had returned to Venezuela from Haiti. Though Peru would remain under Spanish control for another five years, Trevithick's engines (he had shipped four pumping engines and four winding engines ahead of his arrival) were still in their crates when his romantic soul got the better of him and he joined the rebellion. While in Caxatambo, Peru, he even designed a new carbine for Bolivar's army, but when the city was occupied by the Spaniards in 1818, Trevithick was forced to flee north35 to Costa Rica, leaving an estimated 5,000 in ore and uncounted more pounds' worth of lost equipment.

Trevithick's South American adventure carries an almost unwieldy tonnage of symbolism: a representative of the dominant world power of the nineteenth century caught in the collapse of the dominant one of the sixteenth. Even more pointedly, it offers a high-contrast picture comparing history's two longest-lasting approaches to the very idea of wealth: wealth as technology versus wealth as precious metals. Whatever meaning is retrospectively poured into it, however, the experience as Trevithick lived it seems to be less about the metaphorical war between two notions of political economy than about the real thing. Evading Spanish patrols in the Nicaraguan jungles, which the Cornish inventor was forced to traverse on foot, destroyed whatever romance the rebellion still offered. Trevithick's journey, which included a dozen hair's-breadth escapes, the deliberate capsizing of his boat by an offended traveling companion, and bouts of illness too frequent to count, found him arriving at last in Cartagena, Colombia, exhausted, sick, and broke-in his own words, "half-drowned, half-dead, and the rest devoured by alligators."36 There his story took an unlikely turn. In Cartagena, he met the son of an old friend, who lent him 50 for his fare home. When Trevithick finally returned in 1827, he had nothing on his person to show for a decade in South America but two compa.s.ses-one for drafting, the other for navigating-a pair of silver spurs, and his gold watch.

Aficionados of dramatic coincidences could, however, take some comfort in the name of the man who paid for Richard Trevithick's ticket home. He was Robert Stephenson, of Newcastle, and along with his father, George, is Trevithick's only serious compet.i.tor for the t.i.tle of "father of railways."

THE DEPICTION OF GEORGE STEPHENSON by Samuel Smiles, the prolific biographer and self-help author* who did more than anyone else to establish the heroic archetype for British inventors, is a textbook example of self-discipline and deferred gratification. His first job was as a picker: a laborer whose entire job was separating coal from the stones that accompanied it from mineshaft to colliery. Soon enough he was working as an a.s.sistant fireman, then as the "plugman" operating a set of valves on the steam-driven pump at another collier's. When he turned twenty, he was appointed as the brakeman, responsible for maintaining the winding mechanism that pulled the coal-filled buckets from the work area of the mine.

None of this permitted much time for education, even of the practical sort, and in a previous century, Stephenson might have simply become a superbly reliable artisan. By the end of the eighteenth century, however, Britain-particularly outside London-had spent decades making heroes out of onetime laborers who had become wealthy by acquiring and producing useful knowledge. So inspired, Stephenson taught himself to read and write and hired someone to teach him the rudiments of arithmetic. By 1801, the ambitious twenty-two-year-old brakeman took on additional work moonlighting as a watch repairman; two years later, now a father, he took charge of the Boulton & Watt steam engine driving the wheels of a Scottish spinning factory that had grown prosperous making cloth for the military uniforms needed for the war against Napoleon. This did not exempt Stephenson from service himself, nor did the birth of his son, Robert, in 1803; the following year he was drafted for the militia, and went into debt paying for a subst.i.tute to serve in his place. The same year, he returned to the Killingworth pit mine, where he taught himself mechanical engineering by spending his one day off each week dismantling and rea.s.sembling the colliery's steam engine.

In 1811, Stephenson, like Watt thirty years before, made his first real mark on the world repairing a Newcomen engine, this one an old model at one of the Killingworth pits. For the job he was paid 10, and far better, was hired to manage all the engines owned and operated by the collieries of the so-called "grand allies," a group of aristocratic investors that owned the Killingworth pit, at the impressive salary of 100 per year-the equivalent of more than $100,000 in current dollars.37 Stephenson's salary was an insurance policy for the stationary engines on which the colliers depended; it rapidly turned into an investment in an entirely new industry. In 1814, Stephenson built his first locomotive to transport coal at Killingworth: the Blucher, a giant step toward practical steam locomotion.

THE TWO GREAT PROBLEMS in harnessing steam power for transportation were, broadly speaking, both a function of weight. The first one-increasing the engine's power-to-weight ratio-was addressed, if not solved, by the realization, by both Evans and Trevithick, that more heat meant more pressure and therefore more work. That notion, which is obvious in retrospect but was revolutionary at the time, practically demanded a whole series of "micro-inventions" intended to turn up the dial on steam boilers: return flues, for example, which not only "put the fire in the boiler" but increased exponentially the area heating the water. Even more important, exhausting the steam through a chimney located above the furnace created a draft-a "steamblast"-that raised the heat even further.

The other weight problem was the one that licked Trevithick at Penydarren: The tracks on which the locomotive ran were just not able to survive the tonnage traveling over them. Driving a five-ton steam locomotive over rails designed for horse-drawn carts was only slightly more sensible than driving a school bus over a bridge made of wet ice cubes. In both cases, it's a close call whether the vehicle will skid before or after the surface collapses.

This is why all of the dozens of inventors attempting to put steam on the move were obsessed with the durability and traction of the surface holding their vehicles; for centuries, the rails originally designed for horse transport had been made of wood, occasionally reinforced with iron edging. Not until 1767 did the Darbys of Coalbrookdale begin casting iron rails for wagonways, which made them far stronger; within twenty years some unknown innovator had added an arched rim, or lip, to prevent wheels from slipping off.

The rims, or f.l.a.n.g.es, were fine for keeping the wheels from moving laterally, but they did nothing to increase traction-a real challenge for smooth iron wheels on smooth iron rails. In 1811, John Blenkinsop, an employee of another collier located in the city of Leeds, patented a Trevithick-style engine with a cogged driving wheel, and accompanied this with a new sort of track, this one made of cast iron with an edge rail carrying a toothed rack. The cog-and-rack not only eliminated any possibility of skidding, it transmitted five times the force of Trevithick's original engine, and Blenkinsop-style engines remained popular through the 1820s, despite the enormous cost of producing miles of what were essentially horizontal iron gears.

Two years later, a civil engineer named William Chapman applied for and received a patent for an engine that propelled itself by hauling itself along a chain; even odder, William Brunton also managed to patent his "Brunton Mechanical Traveler" that "walked" the locomotive along by operating mechanical feet driven via a complicated series of levers and linkages. Slightly less eyebrow-raising,38 in 1815, William Hedley's "Wylam Dylly" engine tried to solve the excess weight problem by doubling the axles from two to four, thus distributing the weight over a larger area.

Stephenson's locomotive, which made its maiden journey on July 25, 1814, took a different approach. The engine driving the Blucher (named for the Prussian general who would pull the Duke of Wellington's chestnuts out of the fire at Waterloo almost exactly a year hence) incorporated an early version of the blastpipe: a vertical tube with a narrowed exit that carried the exhaust into the chimney, creating a draft, just as Trevithick had more or less accidentally discovered a decade before. It also ran on a reversed version of the most popular track design, putting a f.l.a.n.g.ed wheel on a smooth rail. Two years later, Stephenson, in collaboration with the ironmonger William Losh of Newcastle, produced, and in September 1816 jointly patented, a series of improvements in wheels, suspension, and-most important-the method by which the rails and "chairs" connected one piece of track to another. Stephenson's rails seem mundane next to better-known "eureka" moments, but as much as any other innovation of the day they underline the importance of such micro-inventions in the making of a revolution. For it was the rails that finally made the entire network of devices-engine, linkage, wheel, and track-work.

Stephenson's working life* marks the point in the development of steam technology when the value of what economists call "network effects" finally overtook the importance of any individual invention, however brilliant. Setting the distance between the smooth tracks on which the Blucher traveled at four feet eight and a half inches was arbitrary-that was the width of the Killingworth Colliery wagonway-but its specific width was irrelevant. The value of any standard is not its intrinsic superiority, but the number of people using it. Like the famous example of the QWERTY keyboard, the Stephenson gauge became the world standard, and it is still the width used on more than 60 percent of the world's railroads.

Of course, simply laying rails a particular distance apart does not make for a monopoly unless others follow. And others weren't about to follow Stephenson's lead until they were persuaded that there was some advantage to it, in the form of either increased revenue or lower costs. To a proprietary line, such as the ones that connected coal mines with ports, the advantage of a standard wasn't all that obvious; as at Killingworth, it was frequently more economical to use existing wagonways and roads than to redesign them to a new standard. The same didn't apply to so-called "common carriers," who needed, by definition, to accommodate rolling stock they didn't own, or to travel on railways they didn't build. The first common carrier to realize this,39 the Stockton and Darlington Railway, was, not at all coincidentally, one of George Stephenson's employers. But by far the most important one was the one intended to connect the cities of Manchester and Liverpool.

It is almost indecently tempting to place the Liverpool & Manchester Railway at the climax of the entire history of British industrialization. The first temptation is posed by Manchester itself, which was, when George Stephenson took on the job as chief engineer of the proposed railway in 1825, the most "industrial" spot in all England, with all that implied: "a town of red brick," in the words of Charles d.i.c.kens, "or of brick that would have been red if the smoke and ashes had allowed it."

The reason, of course, that those bricks were covered by smoke and ash was that the city was home to the world's largest textile manufacturers, factories that used coal to turn cotton into clothing. Richard Arkwright's mills, which gave the city its nineteenth-century nickname of "Cottonopolis," had become so successful that the choke point for the industry's growth was no longer technological imbalance (the difference between efficient spinners and inefficient weavers, for example) but transportation. Manchester was making cotton faster than it could ship it, and Britain's ca.n.a.l system, even with its sophisticated locks, was less and less able to handle the load, which was easily exceeding a thousand tons of cargo daily: raw cotton in, finished goods out. So much cloth was being made in Manchester, in fact, that by 1800, the port of Liverpool on the River Mersey was the world's most important; less than eighty years old, it handled more than a third of all the world's trade. The need for a railway to connect Manchester's mills with the port city had become urgent.

It is metaphorically satisfying to talk about threads being woven together when talking about cotton, but the thread that mattered to the Liverpool & Manchester Railway was made of iron: thirty miles of it, smelted, forged, and wrought in ironworks like Coalbrookdale on the Severn, and laid down as rails between the two cities that were now producing, in their mundane way, more wealth in a year than the entire Roman Empire could in a century.

But while there were clearly ma.s.sive financial incentives for building some kind of railway between the factory and the port, the railway's directors were uncertain that a locomotive railway was the best option. Some of the investors and directors in the enterprise were promoting the use of rope cables to haul boxcars full of cotton the entire thirty miles, using stationary engines roughly every mile and a half. Others wanted different kinds of locomotives (though no one, happily, was arguing on behalf of Brunton's mechanical "walker"). After much to-ing and fro-ing, it was decided to settle the problem with a contest.

On May 1, 1829, the Liverpool & Manchester Railway ran an advertis.e.m.e.nt in the Liverpool Mercury inviting "engineers and iron founders" to submit plans for locomotives to compete for the winning design. The offer of a 500 prize, the equivalent in average earnings of more than $500,000 in 2010, brought the crackpots out in force. The treasurer of the Liverpool & Manchester, Henry Booth, described the applications: From professors of philosophy40 down to the humblest mechanic ... [from] England, America, and Continental Europe. Every element and almost every substance were brought into requisition and made subservient to the great work. The friction of the carriages was to be reduced so low that a silk thread would draw them, and the power to be applied was to be so vast as to rend a cable asunder.... Every scheme which the restless ingenuity or prolific imagination of man could devise was liberally offered to the Company....

The oversupply of perfect vacuums and perpetual motion machines was in part a testimony to the utter transformation of British cultural att.i.tudes toward innovation over the preceding century. By the 1820s, the Patent Office was approving nearly three hundred new inventions annually, and rejecting thousands. In the event, the Liverpool & Manchester had made the conditions for entry fairly strict: entries had to be mounted on springs, weighing no more than six tons including water (if on six wheels) or four and a half tons (if on four); they must operate at between 45 and 60 psi, while being prepared for a test at up to 150 psi; they must consume their own smoke (to keep the route as clear of ash as possible; this effectively required the engines to burn c.o.ke rather than coal); and they were required to pull a gross load of twenty tons at ten miles an hour back and forth along a mile-and-a-half course forty times, reproducing the sixty-mile round trip between Manchester and Liverpool.

The stipulations eventually weeded out all but five applicants, only three of which could be called serious. One of the others never actually made it to the starting line, and the other-the Cycloped, whose source of propulsion was a horse trotting on a treadmill and which was only allowed to compete because its designer was on the railway's Board of Directors-proved good for nothing more than comic relief.

Two of the remaining three compet.i.tors were joint favorites to win the prize: the Sans Pareil, built by Timothy Hackworth, master mechanic of the Stockton and Darlington Railway (and therefore George Stephenson's former employer), and the Novelty, the creation of a former Swedish army officer now living in London, John Ericsson.

The third, entered by Henry Booth and George Stephenson and to be built by his son Robert-Richard Trevithick's rescuer, and an even more skilled engineer than his father-was Rocket.

Between May and September of 1829, Robert Stephenson-who had promised his father, "Rely upon it, locomotives41 shall not be cowardly given up. I will fight for them until the last. They are worthy of a conflict"-labored at his workshop in Newcastle-on-Tyne to construct the world-changing locomotive. While it incorporated a key design feature suggested by Booth (the mult.i.tube boiler, about which more below), every other innovation contained in the final entry was the work of Robert, who had explicitly identified four areas for potential improvement in the final design: transmission of the largest amount of power from the pistons to the wheels; preservation of the greatest amount of traction between wheels and track; minimizing the loss of heat between boiler and cylinder; and maximizing the amount of heat within the boiler itself.

Those innovations are the reason that any list of the most significant engines in locomotive history always includes the Stephensons' entry at Rainhill, the site of the compet.i.tion's final trials. First were its mechanics: the way it transmitted the reciprocating motion of its pistons to its wheels. The "premium engine," as the two Stephensons referred to it, used two pistons set at a 45-degree angle above the front axle, each one attached to a slip eccentric, which is a sort of linkage in which a disk is attached to an axle but offset "eccentrically" (essentially a simpler, and more efficient, version of the sun-and-planet gear). One set of slip eccentrics turned the reciprocating motion of the pistons into rotation, while another set worked in reverse, opening and closing the steam valves as the engine cycled.

To increase the amount of traction between wheels and track, Stephenson and his a.s.sistant William Hutchinson calculated the optimal arrangement of weight over the wheels and determined to use the engine to operate only the front wheels; it was far more efficient, both in tractive power and durability, to drive only two large (48 diameter) wheels and use the back wheels (with a diameter of 26) for balance.

Fig. 9: Little though it resembled the great locomotives of the nineteenth century, Rocket pioneered virtually all of their engineering innovations, from the high "blastpipe" chimney to the mult.i.tube firebox to the slip eccentric gears on the driving wheels. National Railway Museum / Science & Society Picture Library But the truly revolutionary significance of the engine was its boiler design. Twenty years before Rainhill, Oliver Evans had demonstrated that raising the boiler's heat by doubling the amount of fuel increased the engine's power by at least ten times; Richard Trevithick had goosed up the heat in his boiler with a U-shaped return flue. The principle was, in retrospect, obvious: Since the water was heated by conduction with the chamber containing heated gas, increasing the surface area of the chamber would transmit more of that heat to the water surrounding it. Robert Stephenson was just about ready to take that principle to its logical conclusion.

Rocket's boiler did not have a single flue, even a U-shaped one. Instead, as suggested by Henry Booth, twenty-five copper tubes, each three inches in diameter, were fitted into a firebox inside a water jacket, with somewhat wider copper tubes connecting them to the barrel of the six-foot-long, three-and-a-half-foot-diameter boiler. The cylinders exhausted their steam into two blast pipes inside the chimney, whose slightly narrowed openings guaranteed a powerful draft of air. Robert Stephenson spent the entire month of September testing to ensure that the boiler and cylinder were reliably steamtight to the point that they could handle up to 150 pounds of pressure per square inch. It finally pa.s.sed Stephenson's inspection only the day before it left his Newcastle workshop and was placed on a series of horse-drawn carts for the 120-mile journey to the Rainhill course, ten miles east of Liverpool.

The first day of the trials, October 6, was largely a day for demonstration, as each compet.i.tor tried the course without hauling the weight required by the contest's rules. Novelty, at two and a half tons, the lightest of the three remaining entrants, was by far the fastest. Using two vertical cylinders to drive a crank attached to the leading axle, it was also, by general consent, the prettiest engine in the compet.i.tion (painted royal blue, with its boiler and water tank covered in polished copper), and it was made the early favorite, a position it improved on the following day, when, hauling more than eleven tons, Novelty easily hit a speed of 20 mph.

On October 8, the final specifications for the contest were published: Each engine was no longer required to haul twenty tons, but a load of three times its weight, including the water in its boiler, with allowance made for the engines-Novelty and Sans Pareil-that hauled water in the locomotive rather than in a separate tender. Though the entrants were to have competed in the order of their "race cards"-Novelty, then Sans Pareil, then Rocket-the first two needed last-minute repairs, and Rocket went first.

Rather surprisingly, given the historical significance and number of spectators, no one knows who actually drove Rocket on its October 8 debut at Rainhill. Robert McCree, from the Killingworth Colliery, had driven it during testing, but at least one report suggests that he was, like Robert Stephenson, only a pa.s.senger (and possibly a fireman, loading fuel into the firebox). If so, the driver could only have been George Stephenson himself, and he, like Rocket, covered himself in glory, along with coal dust. It took only fifty minutes for the fuel (like the other compet.i.tors, Rocket used cleaner-burning c.o.ke, to "consume its own smoke") to bring the pressure in the boiler up to the required 50 psi from a cold start, and by 10:00 A.M., the engine was on its way.

And so it continued. Aware that the rules mandated an average speed of 10 mph, the Stephensons kept their pressure well below its maximum for the first back-and-forth laps. It took a bit more than six minutes, at an average speed of around 15 mph, to complete the first mile and a half: just about the pace of a good twenty-first century fifteen-hundred-meter runner. By the tenth lap, the engine was moving closer to 20 mph, but not until the last lap did the Stephensons open up the steam regulator and let Rocket fly. When they pa.s.sed the grandstand at the eastern end of the course, Rocket was pulling its twenty tons at more than 30 mph, all while consuming "only" a little more than 200 pounds of fuel an hour. Thousands of spectators rushed the finish line to cheer the Stephensons on their triumph.

The rest of the compet.i.tion was something of an anticlimax. Novelty didn't get a chance to compete until Sat.u.r.day, October 10. The same high power-to-weight ratio that had made it such a fan favorite four days earlier allowed it to race off at what must have seemed magical speed, completing its first mile in less than two minutes. Before its second, however, a blowback from the engine's furnace burst the bellows used to create chimney draft. The explosion ended Novelty's day. On its next run, the favorite managed only one lap before another pipe exploded; since this was the pipe that fed the boiler, the resulting detonation ended with "the water flying in all directions."42 When the boiler gave out, Ericsson gave up.

Sans Pareil did perform brilliantly. The heaviest of the three finalists, it pulled a full twenty-four tons at better than 15 mph. But not for long. After twenty-two and a half miles, its boiler, rather embarra.s.singly, ran dry, melting the fusible plug that stopped it cold. The reason was its enormous consumption of fuel: nearly 700 pounds per hour.* The victor, by acclamation, was the Stephensons' Rocket.

IT'S NOT NECESSARILY OBVIOUS that the Rainhill Trials mark the moment in history when the steam revolution became finally, and utterly, inevitable. One year later, the Liverpool & Manchester Railway opened for business, with eight Stephenson-built locomotives traveling on Stephenson's standard-gauge track before luminaries that included the then prime minister, the Duke of Wellington, but the conflicts over the proper use of steam power didn't vanish. To the end of his life, Stephenson fought a running battle with an even more famous engineer, Isambard Kingdom Brunel, over the latter's preference for an "atmospheric railway system" operated by stationary engines. Brunel, the son of Marc Brunel, of the Portsmouth Block Mills, even designed the Great Western Railway to run on a gauge nearly three feet wider than Stephenson's (though he soon discovered the impossibility of overcoming an early monopoly advantage).

There is, after all, something as arbitrary about ending the story of the steam revolution at Rainhill in 1829 as beginning it in first-century Alexandria. Unfortunately for historians, if not for history, such convenient end points are as capricious as the textbook dates for the Industrial Revolution itself, which the careful reader will remember were originally matched as a lecture hall convenience to the regnal years of George III. One might just as well have decided that the story ended in 1819, the year that James Watt and Oliver Evans died-and, coincidentally, the year of the first steamship crossing of the Atlantic, by the American-built Savannah. Or 1824, when Sadi Carnot finally explained the thermodynamics of steam power. Or 1838, when I. K. Brunel's Great Eastern connected a steam railroad with a true transatlantic steamer (the Savannah was really a three-masted sailer, with paddlewheels added).

The reason for ending with Stephenson's triumph nonetheless seems persuasive. Rainhill was a victory not merely for George and Robert Stephenson, but for Thomas Savery and Thomas Newcomen, for James Watt and Matthew Boulton, for Oliver Evans and Richard Trevithick. It was a triumph for the ironmongers of the Severn Valley, the weavers of Lancashire, the colliers of Newcastle, and the miners of Cornwall. It was even a triumph for John Locke and Edward c.o.ke, whose ideas ignited the Rocket just as much as its firebox did.

When the American transcendentalist Ralph Waldo Emerson met Stephenson in 1847, he remarked, "he had the lives of many men in him."43 Perhaps that's what he meant.

* The names of eighteenth-century Cornish mines are as personal, and as obscure, as the names given to thoroughbred racehorses and recreational sailboats.

* Or, indeed, any form of thermal or electromagnetic energy. This particular bit of equivalence, the British Thermal Unit, is an early nineteenth-century measurement that has been mostly replaced by a frighteningly large array of units, including calories (and kilocalories), joules (and kilojoules), electron volts, kilowatt-hours, and therms, each of which can be converted to the others.

* Some histories still insist that in 1543, a naval officer in the service of Charles V of Spain named Blasco da Garay used steam to propel a boat across Barcelona harbor, though the story has been thoroughly debunked for more than a century.

* In the east end of the North Corridor on the first floor of the Senate wing of the U.S. Capitol is a series of frescoes painted by the Italian emigre artist Constantino Brumidi, thematically coordinated with the specific duties of Senate committees; over the doors leading to Room S-116, where the Committee on Patents originally met, are three portraits. Two of the subjects-Benjamin Franklin and Robert Fulton-are as well known as any names in American history. The third is John Fitch.

* The Russell (or Scott Russell) linkage was actually invented and patented in 1803 by the watchmaker William Freemantle and only decades later named for the naval architect John Scott Russell.

* Confusingly so. Steam is actually invisible; the clouds are just evidence that steam has condensed back into water vapor.

* Literally; in addition to biographies of Watt, Smeaton, Maudslay, Dudley, Boulton, and dozens of other inventors and engineers, he also wrote, in 1859, the worldwide bestseller t.i.tled Self-Help: With Ill.u.s.trations of Character and Conduct.

* Not all of Stephenson's historically significant inventions were a.s.sociated with railroads, or even steam. His invention of a safety lamp, one that placed a barrier such as metal gauze between the candle and surrounding gas practically saved the deep coal mining industry. Stephenson's eponymously named "geordie" was virtually simultaneous with a similar one invented by the Cornish chemist, and onetime partner of Richard Trevithick, Humphry Davy; the dispute over primacy continues to this day.

* Hackworth never did accept his loss at Rainhill, and he and his supporters argued that the boiler failure was actually sabotage; perhaps imprudently, Hackworth had ordered it from Robert Stephenson's workshop in Newcastle-on-Tyne. In the event, his accusation was dismissed, and the Liverpool & Manchester Railway ended up buying Sans Pareil.

The inaugural day for the Liverpool & Manchester is famous for the death of Liverpool MP William Huskisson, who was run down by Rocket. Just as widely reported, and far more lauded, was the heroic dash George Stephenson made in Rocket to the nearest hospital, during which he averaged 36 mph for fifteen miles.

EPILOGUE.

THE FUEL OF INTEREST.

LEADVILLE, COLORADO, AT AN elevation of 10,152 feet, is the highest city in the United States, though the term "city" is generous; fewer than three thousand people live there, most of them directly or indirectly supported by tourism. Leadville, like many places in the American West, trades on its history, and it has more to trade on than most. Leadville was where Doc Holliday escaped after the legendary gunfight at Tombstone's O.K. Corral, and the hometown to which the "unsinkable" Molly Brown returned after surviving the sinking of the t.i.tanic. But most of the local color comes from local mines, from which millions of dollars in gold, and especially silver, were extracted in the last decades of the nineteenth century-enough, in fact, that Leadville is home to the National Mining Hall of Fame and Museum.

It is also where, on October 11, 1962, the last regularly scheduled steam locomotive in the United States departed on its fourteen-mile trip to Climax, Colorado. The engine-#641 on the books of the Colorado & Southern Railway-used a mult.i.tube boiler fed by a blastpipe, just like Rocket. Just like Rocket, it ran on standard-gauge track, four feet eight and a half inches wide, just big enough to carry coal down the old wagonway at Killingworth Colliery.

And just like Rocket, engine #641, built in 1906 by Philadelphia's Baldwin Locomotive Works, is practically an encyclopedia of engineering innovations, hundreds of them invented after the Rainhill Trials. In the 1840s, locomotives worldwide adopted a different linkage arrangement-the so-called "valve gear," also a George Stephenson patent-but still connected pistons to wheels using slip eccentrics. By the time engine #641 was being designed, even Stephenson's valve gear was supplanted by a different and superior version invented by the Belgian engineer Egide Walschaerts. Rocket's angled pistons were replaced by horizontal ones. Fireboxes moved forward and back, wheel arrangements changed. Superior pressure gauges replaced the nine-foot-tall mercury tube used at the Rainhill Trials; air brakes were introduced, and then were replaced by ones using vacuum-necessary for stopping twentieth-century locomotives that could be one hundred and twenty feet long and weigh five hundred tons even without freight. By 1900, railroad track in Great Britain covered more than 48,000 miles; in Europe, more than 65,000. The United States, with its enormously greater territory, had laid 193,000 miles of track on its way to a 1930 peak of 230,000.

As on land, so at sea. From the end of the 1860s through the 1920s, oceangoing ships turned their screws using engines with three or more cycles of expansion that were just a logical extension of the original compound engine, each cylinder using exhausted steam at lower temperature (and therefore pressure) in a greater volume of s.p.a.ce, usually by increasing cylinder diameter. Since steam engines need fresh water, using the final stage of condensation for the boilers made possible the great steamships of the early twentieth century. Inventions created to move freight uncovered a new and highly profitable business in transporting large ma.s.ses of people.

Innovation in stationary steam engines was, if anything, even more dramatic. On March 10, 1849, the American George Henry Corliss received a U.S. patent for "certain new and useful improvements in Steam-Engines," and he was being modest. The Corliss engine incorporated a rotary valve (and a version of Watt's centrifugal governor) to offer variable control to the steam and exhaust ports in the cylinders, which resulted in a ma.s.sive increase in efficiency and some extraordinarily ma.s.sive engines: The Corliss Centennial Engine, forty-five feet tall, with a flywheel diameter of thirty feet, produced more than 1,400 horsepower and operated virtually every moving part at the Philadelphia Centennial Exposition of 1876.

It wasn't until twenty years after Rainhill that science finally caught up with steam engineering. In 1851, a Scottish physicist (and onetime railway engineer on the Edinburgh & Dalkeith Railway, where his father was superintendent) named William John McQuorn Rankine published a paper demonstrating that the theoretical efficiency of steam engines-of any heat engines-could be precisely measured by establishing the upper and lower working temperatures of the system. This tempted John Ericsson1 (Novelty's designer, who should have known better) to build what would have been a perpetual motion machine: an attempt to use the heat lost in the exhaust over and over again in a huge machine with four cylinders, each fourteen feet in diameter. Ericsson was not the first, but very nearly the last, inventor to fail to understand that heat, once converted into work, is no longer available as heat. Though Ericsson's engine could save fuel (it was also known, appropriately enough, as an economizer), it could not use the same energy twice.*

More practically, two New Yorkers, John Allen and Charles Porter, revolutionized the ability of steam engines to deliver rotary power, adapting Watt's governor to spin at very high speeds, which an 1858 article in Scientific American declared "if not absolutely perfect in its action,2 is nearly so, as to leave in our opinion nothing further to be desired." This turned out to be critical, since by the 1880s the ability of reciprocating steam engines to drive a rotary gear at high speed had acquired a new purpose: the production of electricity.

The first electric generators-coils of wire, usually copper, spinning between the poles of a magnet-required startlingly high speeds of rotation; an 1887 machine ran at more than 1,600 revolutions per minute. All that spinning produced a lot of power, and demanded a lot. The biggest reciprocating steam engines ever built were ordered in 1899 for the electrical systems of New York City's subway system. The ten-thousand-horsepower monster3 weighed in at more than seven hundred tons, with a series of thirty-foot-high cylinders driving an alternator that, all by itself, weighed 445 tons. Even these ma.s.sive engines were soon replaced by steam turbines, whose thermal efficiency is at least twice that of the best reciprocating engine-turbines convert up to 80 percent of heat energy into work, as opposed to less than 30 percent in a Cornish engine.

Steam turbines produce more than three-quarters of the world's electricity, but they don't drive the successors to Rocket and engine #641. Diesel-electric trains, like automobiles and propeller-driven aircraft, use internal combustion-steam engines, because their furnaces boil water in a chamber outside the cylinder, are external combustion machines-for the same reason that high pressure was needed to put steam on the move in the first place: a superior power-to-weight ratio. The conversion from steam to diesel-electric railroading, in which diesel engines drive electric traction motors, began in the early twentieth century and was completed in most of North America, Europe, and the United Kingdom by the 1960s. The significance of this is less than meets the eye. Steam locomotives may be harder to find outside museums (though not impossible; they remain popular in Asia and Africa, and even on some narrow-gauge lines in western Europe), but steam power is very much a going concern. Though it is now produced mostly by turbines instead of pistons, and delivered not by connecting rods but by copper wires, the world still burns a lot of coal to turn water into steam.

There is no doubt that the thermodynamic gradient between liquid water and steam changed the world, or that its discovery marks one of the most important turning points in history. It is not, however, the "most powerful idea" of this book's t.i.tle. To find the really big turning point in history that we a.s.sociate with steam, and industrialization, we have to look elsewhere.

The cla.s.sical Greeks, in their dramas, called the turning point the (which has retained its original p.r.o.nunciation and definition-"crisis"-for three millennia). The word, derived from a root meaning "I decide," refers to a moment after which the protagonist's fate is changed forever. It seems pretty clear that we know when one of those before-and-after moments occurred. And we know where: three centuries back, in Britain and Britain's colonies.

To many, the before-and-after snapshots do not make a happy comparison; contemporary opinion has become decidedly mixed about humanity's leap into the age of fossil-fueled machinery.

And not just contemporary opinion; the early romantic-in an English literature cla.s.s, it would be capitalized-appeal of the new science didn't survive the first decades of the nineteenth century. Wordsworth, Thackeray, Carlyle, and later Charles d.i.c.kens, John Ruskin, and William Morris were uniformly appalled* by the impact of machines on (take your pick) the rural countryside, the traditional family, the joy of craftsmanship, or any combination thereof.

Their prescience did not, however, extend to the impact of carbon on the planet's atmosphere.

It's a cheap shot to call the movement to reverse human-caused global warming a descendant of Carlyle's sneers about what he called a "Mechanical Age." And it wouldn't much matter if it were. If in the beginning the known costs of industrialization had included irreversible climate change in the form of melting glaciers, rising sea levels, and global disaster, Matthew Boulton himself might have had second thoughts about building machines "for all the world." But probably not; John Ruskin might have lived just as well in a preindustrial world, but pretty much everyone else has done a whole lot better. From 1700 to 2000, the world's population has increased twelvefold-but its production of goods and services a hundredfold.

This is why, against all odds, the first decades of industrialization actually have something useful to say about their long-term impact on the world's climate-though it isn't what either side in the global warming debate would probably endorse. It certainly doesn't give much comfort to anyone who thinks humanity can be persuaded to spend any more for power than it has to; America and Europe might have finally so enriched themselves that they can afford to convert to wind, water, and solar power, but neither China nor India is likely to choose either over coal costing one-tenth as much. If the history of steam power teaches anything, it is that the lower-cost fuel option always wins. Right now, that option is about a trillion tons of easily mined, dirty, carbon-rich coal.

What this means, given the very real dangers of climate change, is that any comprehensive solution is going to have to do one of two things: figure out how to return all that carbon to where it was before humans learned how to exhaust it into the atmosphere-the technical term for putting carbon back is sequestration-or come up with a non-carbon-producing energy system that costs less than coal. Both options put the highest possible premium on invention. Phrased another way: There may be no way to put the genie of sustained invention back in the bottle, but we can put the genie to work.

By now, readers will have made up their minds about whether inventions and inventors deserve to hold center stage in the three-hundred-year dramatic crisis triggered by the genie's appearance. The previous three hundred or so pages have been largely an attempt to demonstrate how the inventions created the crisis, how the inventors created the inventions, and even how the birth of an idea about property "created" enough inventors to get the whole drama moving. The next few will try to examine what kept it moving, and moving in the same direction.

IF THERE IS ONE consistent theme in the story of innovation, it is its reflexive character. Without deep coal mines, there would not only have been no need for steam-powered pumps to drain them, there would have been no fuel for the pumps. The cast iron used to manufacture boilers, cylinders, pistons, and gears had impurities hammered from its "blooms" by steam-driven hammers. The primary cargo for the first coal-driven locomotives was coal itself; a close second was the iron ore that was smelted and wrought into six-foot rail segments. These are all examples of the capacity of technological advances to spill over into the economy at large, and so multiply their initial effects; Wilkinson's 1774 patent on his boring machine didn't just enrich the inventor, but enabled the growth of Boulton & Watt.

Technological spillovers aren't the only kind that matter economically. In a cla.s.sic 1991 paper, the future n.o.bel Prizewinning economist Paul Krugman identified what he called "pecuniary spillovers": the tendency of industry to cl.u.s.ter in order to exploit lower costs, from both economies of scale and lowered transportation expense. Once a tipping point is reached-once an economy derives more value from making things than, for example, growing them-manufacturing will tend to establish itself in regions with other manufacturers, attracting still more manufacturers.

Krugman's economic geography is partly about s.p.a.ce, explaining why some areas of the globe are wealthier than others. But it is also, even more importantly, about time. The term in general use is that economic growth is highly "path-dependent"-that is, once started down a path of growth, a society tends to continue on that path. As Krugman himself put it, "Small changes in the parameters of the economy4 may have large effects on its qualitative behavior ... when some index that takes into account transportation cost, economies of scale, and the share of nonagricultural goods in expenditures crosses a critical threshold, population will start to concentrate and regions to diverge; once started, this process will feed on itself" (emphasis added).