A few miles north of Koblenz, Germany, along a picturesque stretch of the Rhine River that meanders through the low rolling hills of the Neuwied Basin is the town of Andernach. This innocuous municipality, chiefly known today for its “cold-water” geyser and the modest remains of a medieval fortification, is actually one of the oldest European settlements north of Italy. When the Romans founded the town of Antunnacum here in 17 BCE, it was already a Celtic settlement called Antunnuac, meaning “Antunnos's Village.” The identity of this Antunnos has been lost over time and through shifting cultural allegiances and languages.
For hundreds of thousands of years, the land around Andernach was volcanically active, and many of the surrounding hills are actually the eroded remains of cinder cones. The Romans found the local igneous stone ideally suited for building purposes and, when pulverized, a perfect pozzolana for making concrete. The locals would later call the stone trass, probably a word that has its origins in terra, the Latin word for earth. The special properties of trass were lost in the upheavals that followed the fall of the Roman Empire.
Sometime in the sixteenth century, the people of Andernach discovered that trass was ideal for carving millstones. It was soft enough to easily chisel but hard enough to grind grain without incurring very much wear. It wasn't long before millstones became one of Andernach's chief exports. The leftover chips and powder from manufacturing the millstones were probably dumped into a pit—or the Rhine—before someone figured out a useful purpose for them. Some bricklayer evidently tried substituting powdered trass for sand in his lime mortar and discovered that once it had set, it was harder and more durable than regular mortar. It also set and held up well underwater. This forgotten experimenter had rediscovered the secret of Roman concrete. Sometime in the seventeenth century, word about the remarkable properties of trass reached the ears of the Dutch.
Dutch traders had plied the Rhine for many centuries. The late seventeenth century was the “Golden Age” of the Dutch Republic: the Dutch had recently thrown off Spanish rule and founded a republic that many economists regard as the first fully capitalistic society. Their excellent navy, manned by first-rate seamen, allowed the Dutch to grab colonies around the world, including the lucrative Spice Islands of Indonesia and its archipelago. One reason for the success of the Dutch Republic was its citizens' fiercely mercantile nature, for they were always on the lookout for interesting business opportunities. Trass looked interesting.
The Dutch tried mixing the trass with lime, and saw that it worked. Because they had been building dykes, canals, and levies for many years, they immediately recognized the commercial potential of this hydraulic building material. The once worthless leftovers from carving millstones were quickly scooped up by the Lowland traders.1 Once this supply was gone, they probably accepted uncut rocks too small to carve into millstones. My guess is that they actually preferred the raw stones. Rocks were the most common form of ballast at that time, and by putting rocks in the holds of their ships, they could sneak it past customs, something you couldn't do with a barrel of powder. Once back in Holland, the traders would then pulverize the trass.
Almost as soon as the Dutch satisfied the domestic demand for trass, they began selling it to the French and British. They sold some trass, but not much: it was viewed as a specialty product whose use was mainly restricted to marine masonry. British engineer John Grundy and his son, John Grundy Jr., used trass for their sluice works on the River Witham in the mid-eighteenth century.2 French engineer Bernard Forest de Bélidor mentions it as well in his book Architecture hydraulique, published in 1748.3 If the Dutch had had more marketing savvy, they would have called the product “Roman cement” instead of “trass,” which sounds too much like the English word trash or the French word travers, which means “failure.” The Dutch would later change the name to “terras,” which had a better ring to it—and was coincidently cognate with its etymological origins—but by that time, the French and British were already trying to create their own versions. The eventual result would be the discovery of natural cement and, later, something even better: Portland cement.
JOHN SMEATON'S DISCOVERY OF NATURAL CEMENT
In the second half of eighteenth century, one British engineer stood in preeminence over all others: John Smeaton. He was born in 1724 in Austhorpe, a small town that is now a parish of Leeds, England, and from early childhood he showed a precocious interest in mechanical devices and architecture. Despite these early signs of his natural proclivities, Smeaton dutifully followed his father's desire that he study law instead (the elder Smeaton's profession). Smeaton spent a couple years at his father's law firm but could not endure work for which he had no native aptitude. He left the firm with his father's grudging blessings and became a maker of scientific instruments instead. His improved marine compass and other advanced instruments were noted by the Royal Society, which made him a member. Smeaton went on to improve the efficiency of steam engines and introduced the term horsepower to calculate their relative workload capacity, an innovation often wrongly attributed to James Watt.4 (We now know that Watt, inventor of the greatly improved steam engine utilizing a separate condenser, was overoptimistic about horsepower force, while Smeaton's estimate is closer to its true value.) Smeaton also improved the efficiency of watermills and windmills. For the latter, he developed a formula that addressed the effect that air pressure had on the velocity of objects, specifically the foils of a windmill vane. This formula was later refined and called Smeaton's Coefficient and was used by the Wright brothers in the construction of their early airplane. Smeaton is also known for having first coined the term civil engineer, which he applied to himself to distinguish his profession from that of military engineers.
Smeaton was similar in many respects to his ancient predecessor Vitruvius. Both men were fascinated by architectural and mechanical engineering, and both were honest, conservative, and cautious individuals who first familiarized themselves with the details of a particular field of study before attempting to practice it or introduce any improvements. Smeaton was definitely the more innovative of the two, and there is hardly a subject that captured his attention to which he did not make some valuable contribution.
However, it was Smeaton's many civil engineering projects that firmly established his fame. Smeaton does not seem to have had much of a life outside his work. He married at age twenty-two and had two daughters, but his family probably did not enjoy his presence as much as they would have liked. By his thirties, he was designing and overseeing the construction of a number of major engineering projects in Scotland and North England, some concurrently. At one point, Smeaton was simultaneously overseeing the building of the Perth and Coldstream Bridges, the Ripon Canal (designed by William Jessop), the Forth and Clyde Canal, and the canalization of the River Lee (the Lee Navigation). When Smeaton had a quiet moment outside a jangling carriage or away from work, he wrote scientific articles or corresponded with his employers or friends.5 One wonders whether Smeaton, like Thomas Edison, required only several hours of sleep each night, for the list of his achievements is quite long. Most of his major architectural endeavors are still with us, as he built with the same solidity of the Romans, especially his arched bridges, which would have been constructed in much the same way in ancient times. However, it is his lighthouse for which Smeaton is mostly remembered today. It is also a milestone in the chronicle of concrete, but not for the reason usually given: its use of hydraulic mortar. Smeaton had discovered something about concrete that would eventually change the world.
THE EDDYSTONE LIGHTHOUSE
Lying at the mouth of the entrance to Plymouth Harbor in southwest England are the Eddystone Rocks. The rocks are treacherous stony outcrops rising precipitously from the sea that have destroyed ships and claimed the lives of their seamen ever since the Bronze Age. Obviously, a lighthouse was needed. The first was designed in 1695 by Henry Winstanley, and he began building it the following year.6 During construction of the lighthouse, a French privateer captured Winstanley during one of the many conflicts between the two kingdoms. The Sun King, Louis XIV, ordered Winstanley's release in a noble gesture that was reiterated by his famous statement “France is at war with England, not humanity.” Once Winstanley was freed, he immediately went back to completing his lighthouse, which was first lit on November 14, 1698. It was an octagonal (eight-sided) wood structure that barely survived its first winter, so Winstanley rebuilt it. The result was a dodecagonal (twelve-sided) stone edifice constructed on a wooden frame. The new tower held up much better against storms, and Winstanley bragged that he would not mind being in the structure during the “greatest storm.” On November 27, 1703, a few days after Winstanley toasted the lighthouse's fifth anniversary, a veritable hurricane called the Great Storm of 1703 smashed into the southeastern coast of Britain. Winstanley would get his wish, for he was at the lighthouse with five construction workers making repairs when the gale hit. The lighthouse held up to the storm's fury during the day, but by evening the stone blocks began to shift—they were bound by standard, non-hydraulic mortar—and this stressed the internal wood substructure. Finally, the whole lighthouse collapsed, killing Winstanley and several workers.7
Another lighthouse was built a few years later and lit in 1709. It was a firmly built wooden structure that seemed immune to the most ferocious storms. Nevertheless, like all lighthouses back then, a fire had to be continually maintained for its beacon, and since fire has a strong affinity for wood, the inevitable happened. A blaze broke out near the lamp in 1755 and quickly consumed the structure, killing one of the three lighthouse keepers.
Just weeks after the destruction of the second lighthouse, Smeaton was commissioned by the Royal Society to build its replacement. Evidently the society felt that if any man could build a permanent lighthouse on the Eddystone Rocks, that man was John Smeaton.
Smeaton, who was given considerable latitude in the design, was determined that his lighthouse be the best-built in the world. Before beginning work on the structure, he hunkered down and began conducting experiments on stones and mortars. He quickly came to the conclusion that granite, the most durable of building stones, would be perfect. And to make sure that no storm would ever move the granite blocks, Smeaton specified that they have dovetail joints at their ends to secure them in place, a provision that must have annoyed the stonecutters, who probably had to resharpen their chisels several times a day. As a further precaution against the elements wreaking havoc on the granite masonry, Smeaton began testing the properties of different hydraulic mortars, and it was with these experiments that he would help usher in a new era in construction technology.
Since at least Roman times, the quality of limestone was judged by its hardness and the purity of its whiteness (a strong indicator of a high calcium carbonate content). Smeaton decided to ignore accepted knowledge and perform his own experiments. He tested lime taken from a variety of different limestone outcrops in England. Smeaton began by rolling up balls of lime and other materials (like trass or plaster) two inches (ca. 51 mm) thick and then allowing them to dry before dropping the balls in boiling water to test their hydraulic properties. He found, not surprisingly, that pure lime, while quite hard, slowly dissolved in water. By adding trass to the lime, Smeaton confirmed that it created a fine hydraulic mortar. However, Smeaton also found that lime produced from limestone quarried near the small town of Aberthaw on the south coast of Wales appeared to have very good hydraulic properties, even without the addition of trass. To discover its constituent parts, he submersed pieces of the Aberthaw limestone in a water and nitric acid solution called aqua fortis (Latin for “strong water”) used to separate minerals in the mining industry. It showed that approximately 11 percent of the Aberthaw limestone was clay. Smeaton had rediscovered natural cement, which had been used off and on since the Neolithic period, most notably by the Mayans. The Romans recognized that kiln clay, in the form of pulverized pottery shards or bricks, provided caementis with hydraulic properties, but they preferred using pure limestone because it allowed them to control the admixture of pozzolana, whether it was ceramic dust or volcanic soil. Thanks to Smeaton's discoveries, the primary concrete cement and mortar that would be used over the next century would be natural cement sourced from limestone adulterated with clay.
Smeaton added trass to the natural cement and discovered that its hydraulic properties were further enhanced. He then substituted Italian pozzolana for the trass, and found that this combination was slightly better. Since Italian pozzolana was harder to obtain, Smeaton probably would have settled on using the trass instead but for a fortuitous coincidence. A few years earlier, a British merchant had ordered a large consignment of this same Italian pozzolana on speculation, hoping to sell it to the people who were about to build the Westminster Bridge. But the bridge builders showed no interest in using the material, and the merchant was stuck with the pozzolana. Smeaton bought the merchant's pozzolana—which no doubt made the merchant happy—and soon began construction of the new Eddystone Lighthouse.8
The granite stones were cut at the small town of Millway, near Plymouth, and then transported by boat to the Eddystone Rocks, where they were assembled and mortared into place. The lighthouse was completed in October 1759. Thanks to hydraulic mortar and the dovetail joints of the granite blocks, the lighthouse can be ranked as one of the most solid works of stone masonry in existence. It is justly regarded as one of the jewels of eighteenth-century British engineering. Smeaton would go on to build bridges and canals throughout Britain, most of which still remain with us today, carrying boats, people, cars, buses, and trucks to their appointed destinations.
By the late 1780s, Smeaton began feeling the increasing fatigue and decreasing acuity that comes to many of us upon entering our seventh decade. His wife, Anne, had recently died, his daughters had married, and perhaps he thought it was time to settle down. He retired to his home in Austhorpe, where he began collecting and editing his vast volume of papers and articles for publication. One pleasant September day in 1792, while strolling in his garden, Smeaton suffered a stroke and was carried into his house by several servants. Though mostly paralyzed, he was said to have “still retained his faculties.” He died six weeks later, on October 28, 1792.
A story published after Smeaton's death serves as perhaps the engineer's best epithet. A man overheard several young boys debating on which his torical figure they would choose to be. One young man said that he would like to have been Julius Caesar, while another opted for Alexander the Great. The third boy, displaying a wisdom belying his age, said that he would like to have been John Smeaton, explaining that Smeaton had improved peoples' lives, while the others had sought glory at the cost of lives. It is a fitting tribute to a man who never took out a patent on his discoveries, choosing instead to share his knowledge with the world.9
Smeaton's lighthouse remained in use until 1877, by which time the rock beneath the lighthouse had eroded so much from wave action that the lighthouse shook during stormy weather. In effect, the lighthouse was far stronger than the stone on which it was built. When word spread that Smeaton's lighthouse was to be demolished, a public outcry arose, demanding that it be saved. The lighthouse was laboriously disassembled and reconstructed on a square in Plymouth overlooking the sea. Today, it is as beautiful and solid as it was over a quarter of a millennium ago. However, Smeaton's lighthouse could have remained where it was, had it not been for a false notion about the effects of seawater and concrete, one that Smeaton himself shared. Smeaton, noticing that lime stucco mixed using seawater was not as strong as stucco mixed using freshwater, reasonably assumed that the same was true with hydraulic mortars. However, the Romans had discovered that concrete mixed with seawater to make monolithic structures worked well, as demonstrated by the harbor emplacements they built in Caesarea and elsewhere in the Mediterranean. If a cofferdam had been constructed around the eroded rock and filled with concrete and aggregate, Smeaton's lighthouse could have remained on the Eddystone Rocks to this day. The difficulty lay not only in attitudes about seawater and concrete but also in the fact that monolithic concrete construction was still at an experimental stage at this time. Despite a few notable exceptions, concrete was still primarily used as a hydraulic mortar or stucco during the first three quarters of the nineteenth century. Nevertheless, the discoveries made by Smeaton in his experiments on lime mortars marked a turning point in construction history, and men throughout Britain would continue to experiment with different mixtures and manufacturing techniques to create cement of better quality.
ROMAN CEMENT
The revolution begun by Smeaton did not take place immediately after the construction of the Eddystone Lighthouse but several decades later. Smeaton did not publish an article about hydraulic mortars until 1775, but it was a short piece, barely one and a half pages long, and it did not mention his detailed experiments that led to the discovery of natural cement. Among the papers he did see go to press just before his death was his “A Narrative of the Building and a Description of the Construction of the Eddystone Lighthouse with Stone,” published in 1791.10 In this work, Smeaton provides a thorough account of his experiments with various limestones and mortars. Not long after the publication of this paper, a patent would be filed for something that would soon be called “Roman cement.”
First, let's take a quick look at an earlier patent filed in 1779 by the Irish-born chemist Bryan Higgins, who published a booklet the following year titled Experiments and Observations Made with the View of Improving the Art of Composing and Applying Calcareous Cements, and of Preparing Quicklime. Theory of These, and Specification of the Author's Cheap and Durable Cement for Building, Incrustation, or Stuccoing, and Artificial Stone.11 Because Higgins was an otherwise esteemed chemist, early chroniclers of concrete's history have included his patent and book in the material's story, but his product was unstable and did not have the long-term endurance of good hydraulic mortars or concrete.
Of more interest are the two patents filed by James Parker, reportedly an English clergyman and civil engineer. (A later historian who conducted a search of many ecclesiastical and academic records was unable to discover an engineering, architectural, divinity, or any other degree awarded to Parker.) Parker's first patent, filed in 1791,12 speaks of a hydraulic material using “bricks and tiles” and of calcinating the mixture “with a material not previously used for the purpose.” The latter was simply peat, and as for the ceramic ingredients, people had already begun mixing pulverized bricks or tiles with lime after an English translation of Vitruvius's On Architecture by William Newton had been published in 1771.
Parker's second patent (1796),13 filed five years after Smeaton's book was published, demands especially close scrutiny. It is for natural cement. An anonymous article published in 1830, based on an account “written down by him [the anonymous author] many years earlier” explains how Parker made his discovery of “Roman cement”:
It was first discovered by the Rev. Dr Parker in the year 1796 and like many other of our most useful acquisitions, was purely accidental. When on a visit to the Isle of Sheppey, he was strolling along under its high cliffs on the northern side and was struck by the singular uniformity of character of the stones upon the beach and which were also observable sticking in the cliffs here and there. On the beach, however, the accumulation of ages, they lay very thick. He took home with him two or three in his pocket and without any precise object in view, threw one on to the parlour fire from which in the course of the day it rolled out thoroughly calcined. In the evening he was please to recognise his old friend upon the hearth, and the result of some unpremeditated experiments with it has been the introduction to this country of strong, durable and valuable cement.14
Of course, this limestone had enough clay admixture to make natural cement.
This account of Parker's discovery raises many suspicions. Parker brings home some stones “without any precise object in view” and throws one of them in the fireplace where it—thoroughly “calcined” after just a few hours—rolls down onto the floor. He then conducts some “unpremeditated experiments” and discovers natural cement, independently of Smeaton and—at least by suggestion, if not by word—without having read the master's work on the subject.
Let's go back in time several years. In 1792, the year following the publication of Smeaton's book about the building of the Eddystone Lighthouse and his discovery of natural cement, Parker leased some land at Sheppey.15 His kiln was already in operation at Northfleet, not too far from Sheppey, and he had established a London office by 1773.16 And the story of Parker's subsequent discovery has as many holes as a block of Swiss cheese. A man who had patented a mortar five years earlier strolls around the land he had already leased—for what purpose?—picks up some limestone rocks and later calcinates one of them (apparently after only a few hours!) “without any object in view” and then performs “unpremeditated” experiments on them? This story is obviously based on Parker's own account, which apparently no one closely examined. The most rational conclusion is that Parker used Smeaton's research to file a patent that, by all rights, should have been denied but was not. In a stroke of marketing genius not uncommon among borderline shysters, Parker would call his product “Roman Cement” (something the Dutch should have done with trass a century earlier). Of course, it was nothing of the sort, but the name was an excellent choice. As with Higgins's work, chroniclers of concrete's history have listed Parker's “Roman Cement” as some sort of milestone, when, in fact, the achievement was Smeaton's. Parker's ill-gained patent would also delay by a few years the widespread use of an important mineral freely provided by Nature.
The year 1796 was a busy one for Mr. Parker. Sometime in February or March, Parker approached the British Society for Extending the Fisheries and Improving the Seacoasts of This Kingdom to interest them in his hydraulic mortar and stucco. On March 17, the society directed one of their engineers, Thomas Telford, to examine Parker's product. Parker then convinced Telford—after two meetings at the former's house—to write a glowing testimonial about his cement (dated April 12, 1796), which Parker immediately printed and distributed as an “impartial and disinterested report” from “an eminent Engineer,” even though Telford's language was hardly objective. (Telford concluded his remarks by writing that “I was glad to embrace this opportunity of doing justice to a discovery which may become of considerable importance to the Public, and which appears to merit its attention.”17)
On July 27, 1796, Parker was granted his second and more famous patent for what he called “Parker's cement,” which he soon re-dubbed “Roman cement.” To disguise the fact that it was limestone adulterated with clay, he described it in the patent as clay containing “calcareous matter.” Now armed with a patent and a glowing report by an “impartial” engineer, Parker sold his cement works, patent rights, and leased land to Samuel and Charles Wyatt, and then sailed for America. There is no evidence that Parker produced a large quantity of Roman cement, but enough had been used to show Telford its qualities. Although Parker had leased the land on Sheppey, he did not own the mineral rights, a legal issue that he left the Wyatts to sort out at great expense.18 Parker probably just took enough stone to make small batches of his cement, while being careful not to prompt the suspicions of the locals. It is not surprising that Parker went to America: he no doubt knew that large-scale extraction of the Sheppey stone would eventually lead to a court battle. He was also probably worried that someone would draw attention to Smeaton's work and contest his patent rights, perhaps one reason why he delayed applying for the patent until after everything else was in place. Fortunately for the Wyatts, and unfortunately for the world, no one did contest the patent. As for James Parker, he died shortly after arriving in America.19
Samuel Wyatt was an architect and builder, and Charles (Samuel's cousin) was a tinned copper sheet and pipe manufacturer. Both were respected businessmen who had good ties to the construction industry. The Wyatts renamed the London cement works Parker and Wyatt Cement and Stucco Manufacturers. Parker's name was preserved to publicize the fact that the Wyatts now owned the patent rights. Samuel soon withdrew from any active participation in the cement business, and Charles seems to have been in full control after 1800. Once the legal wrangling was over—a compensation package settled the issue—the stone from the Sheppey quarry continued once more to supply the company's needs. When limestone with similar properties was found on the Essex coast, the company used this for their product as well. The firm of Parker and Wyatt would be so successful that all natural cement would thereafter come to be known as Roman cement. (This would have no doubt pleased the late Mr. Parker.) Thomas Telford, whom we met earlier, used it for building bridges, harbor works, and the beautiful Chirk aqueduct in North Wales—an arched masonry structure resembling the aqueducts of ancient Rome. Telford's enthusiasm for the product was apparently real.
Thanks to Smeaton's discoveries, Parker's dubious patent, and Charles Wyatt's sound business practices, the primary concrete cement that would be used over the next sixty years in Britain would be natural cement. Although it was called Roman cement, some of it was actually better, since the hydraulic element—clay—was kilned together with the limestone, creating a stronger molecular bond. Hydraulic mortars and stuccos gained popularity in Britain, and they were soon being used beyond marine applications. The weather in Northern Europe is damp, and conventional lime mortars and stuccos eventually wear away and need to be reapplied. Stuccos were especially valued, as most people found exposed brickwork unsightly. The prevailing taste held that covering a brick building with stucco, which was then indented to give the appearance of stone mortar joints, imparted a sense of dignity to the structure. However, after a decade or two of freeze-and-thaw cycles, the stuccoed building's dignity would be considerably diminished. On the other hand, hydraulic stuccos were found to be hardier and, while not completely immune to environmental factors, they lasted much longer. The one disadvantage of Roman cement was its color, which was light brown. For this reason, stucco made from Roman cement often had to be whitewashed after drying.
A profusion of new—and allegedly better—hydraulic mortars and stuccos were patented and peddled in early nineteenth-century Britain. Most manufacturers claimed that the “superiority” of their product was due to novel or unique ingredients or an improved manufacturing process. A few of these products were indeed better, but most were not. One of the latter was “oil stucco.” Since oil repels water, it was thought that the addition of linseed oil would make the hydraulic stucco even better. It seemed to work, and after drying, the surface could be smoothed to resemble polished stone. But what was gained in appearance and water resistance by the linseed oil was balanced by a lack of adhesion. Not many years passed before oil stucco began peeling off buildings throughout England, especially in London, and most of the firms manufacturing this particular product quietly closed their doors.20
In Britain, patents were—as they are now—valid for fourteen years. As the 1810 expiration date of Parker's patent approached, people around Britain and on the Continent made preparations to manufacture and market Roman cement, a brand name that had become a generic term for natural cement (trademarks often expired with patents at that time).
Among those in the best position to take advantage of the expiration of Parker's patent was Charles Francis of Vauxhall, London. Francis was an architect who primarily made his living as a brick, marble, terras (trass), and cement wholesaler. He also had a wharf on the Thames that served his extensive business. Francis's background as an architect gave him an intimate knowledge of the building industry and its raw material needs. By 1808, though only thirty years old, he was managing a thriving business and had established a host of valuable commercial contacts throughout Britain. With his intimate knowledge of lime kilning and cements, Francis believed that he could produce Roman cement of equal if not better quality to Wyatt's. By 1808, he was already making plans to be among the first to benefit from the expiration of Parker's patent two years later.21
Francis designed more efficient kilns and wanted to secure firm quarrying rights to the appropriate stone (he had no desire to be involved in a legal imbroglio like the Wyatts had experienced). The amount of financing required for an operation of this scale could not be met by his own resources, so he sought a partner. In late 1808, a mutual friend introduced Francis to John Bazley White, a former banker who was then an executive with a firm importing goods from the East Indies. White was intrigued by Francis's plans. He also appreciated the fact that Francis had proven himself a good businessman, knew the industry well, had a strong base of loyal customers, and possessed numerous business contacts. A legal partnership was formed between the two men in July 1809, and the firm Francis & White was born. It would go on to become one of the most successful manufacturers of Roman cement in Britain and eclipse the fortunes of Parker and Wyatt.22
Francis immediately began traveling around Britain, looking for the appropriate clay limestone. He found that most of the promising outcrops were, like those in Sheppey, along the east and south coasts of England. Once the rights were secured for the stone, Francis built a large kiln that had elements both new and old. English forests had been shrinking for centuries, and the huge demand for lumber to build the vast fleet of ships used by the Royal Navy in the Napoleonic Wars (two thousand trees had to be harvested for each of the larger vessels) wiped out many of the few remaining British woodlands. Fortunately, the new energy demands of the Industrial Age coincided with England's expansion of her coal mining and gas industries. Satisfying the vast demands for fuel to power steam engines, foundries, and limekilns was no longer a problem. The kilns that Francis built seemed, at first glance, no different from Cato's. The ancient Burgundy bottle shape remained, but the kilns were far larger, and the way they were fueled and operated was also different. Coal—and later coke—allowed higher temperatures and greater efficiency than wood. Boys were hired for a few pence a day to break down the limestone with hammers to a size suitable for kilning (no piece could be more than a few inches in circumference), a monotonous task that kept the youngsters busy from dawn to nightfall. A layer of coal one foot thick (ca. 30 cm), was laid down, upon which a layer of limestone rocks of the same thickness was laid. This pattern of alternating layers of limestone and coal was repeated until the top of the hearth was reached, just below the chimney. The kiln was then lit from beneath the bottom iron rack that held the first layer of coal. These first layers of coal and limestone were allowed to burn for a couple days and nights before being pushed out with the rack to allow the next layer of limestone and coal (the latter having ignited by this time) to cook. The amount of limestone that could be burned at one time in such a kiln was far higher than in Cato's time—reportedly over a couple hundred tons in the larger bottle ovens. The kilned chunks of lime and clay, which were then pulverized, were said to be “as light as cork.” As demand grew, more bottle kilns were built, often physically adjoining one another to save masonry and space. Bricks, being fireproof, were the preferred building material. The mortar used for the masonry often contained a mixture of brick dust, which helped against the heat, but the masonry seams of the kiln's interior still had to be repointed regularly because of exfoliation. Eventually, larger square kilns replaced the bottle kilns, their shape being more conducive to layer racking.23
For some reason, the cement produced by Francis & White became the preferred product of its day. The company often used stone from the same quarries as Parker and Wyatt, but the cement produced by the former was judged to be better. Perhaps Francis discovered that by weighing the rock, he could better judge its relative proportion of clay and limestone. (The company offered different grades of cement, though this was not uncommon at the time.)
Another reason for the company's success could be the degree of cooperation and professional advice they offered their clients, which was considerable. Most notable in this respect was a major engineering project that, upon its completion, would be called the “Ninth Wonder of the World.” The builder of this wonder was Marc Brunel, whose life and career is worth reviewing, for, as the old saying goes, “You can't make this stuff up.”
MARC BRUNEL
The Chinese curse of having to live through “interesting times” could certainly be applied to Marc Isambard Brunel. Brunel was born to a prosperous French farmer and his wife in the Normandy village of Hacqueville in 1769.24 Brunel, like Smeaton, exhibited a childhood interest in building things, and he enjoyed peering into clockworks to better understand their operation. Both men also had fathers who initially preferred that they take up professions to which they were temperamentally and intellectually unsuited. Unlike Smeaton, Brunel faced extraordinary difficulties throughout his life. Since his family was devoutly Roman Catholic, they followed the tradition of consigning the inheritance of the estate to their first-born son, while the second was pledged to the Church. In other words, Marc was destined—at least in his parents' eyes—to become a priest. The priesthood required a firm background in the classics, but Brunel showed no interest in learning Greek or Latin. He did, however, display a remarkable aptitude in mathematics, drafting, and music (the boy—then eight years old—could also make his own musical instruments).25 Despite these early signs of a proclivity toward engineering, Brunel's father instead pushed him to do better in ancient languages. Brunel finally rebelled. At age eleven, Brunel firmly announced to his father that he had absolutely no desire to be a clergyman and instead wanted to be an engineer. Nothing could sway him from this determination, just as nothing could sway his father's insistence that he become a priest, so the father packed the boy off to the Seminary of Sainte Nicaise in Rouen, hoping that Marc would forget his silly notions and learn to serve God instead. Fortunately for young Brunel, the seminary's superior was an open-minded individual who believed that God-given talents should be expressed, not suppressed. Noting that the boy enjoyed designing and building things, he allowed him to learn carpentry, a craft that the youngster was soon practicing with the skill of a master cabinetmaker. The boy was also given paper and charcoal pencils and allowed to draw. Instead of landscapes, Brunel sketched the ships in Rouen's harbor, producing renderings of startling realism that clearly demonstrated the youth had a particularly fine eye for proportion and detail. Brunel's father, informed that the boy's gifts lay outside the Church, finally gave in. Brunel was sent to live with his cousin, Mme. Carpentier, whose husband, François Carpentier, was the American consul in Rouen. Carpentier, a retired sea captain, instructed the boy in naval matters, while another family friend, Vincent Dulague, who taught hydrology at the Royal College at Rouen, tutored Brunel in the sciences. The French Royal Navy was then undergoing progressive reforms instituted by Charles de La Croix (Marechal de Castries), the minister of marine affairs. De La Croix was assiduously recruiting young men with strong technical backgrounds and promising them good opportunities for exercising their gifts.
In 1786, Brunel became a midshipman on a French frigate that embarked on a six-year tour of duty in the West Indies. While onboard, Brunel used his spare time to learn English, bone up on his astronomy, and design a superior quadrant that he then constructed of brass and ivory. Brunel's ship was in the Indies when the French Revolution broke out in 1789, and when the frigate returned in 1792, the country was in chaos. Since the ship's captain was receiving conflicting orders and reports from Paris, he decided to pay off the crew and dismiss them from service. Royalist sentiment was very strong in Brittany and Normandy, and Brunel shared these views. One year after his dismissal from the navy, Brunel was in Paris personally observing the tumultuous events that were reverberating across France and Europe. King Louis XVI was then being tried for treason, and a prominent revolutionary leader, Maximilien de Robespierre, was vehemently arguing that the former monarch be sentenced to death. According to one account, Brunel was at a café when word came that the king had been found guilty and would be beheaded. Brunel, perhaps forgetting that he was in Paris and not Rouen, cursed Robespierre and predicted that he would one day suffer the same fate for his cruelty. Several revolutionaries at the café immediately arose to defend Robespierre and began questioning Brunel's loyalty to the republic. A melee broke out, and Brunel barely escaped. Another account relates that Brunel, who had brought his dog with him to Paris, continually addressed the canine as Citoyen (citizen) in public, the common greeting among republicans. In any event, Brunel was forced to leave Paris to avoid arrest and probable execution. The fate of his dog is unknown.
Brunel found refuge with the Carpentiers in Rouen, who enjoyed diplomatic immunity. While there, Brunel fell in love with their English governess, Sophia Kingdom, and proposed to her. Unfortunately, the Revolution turned even uglier, and “traitors” were now hunted down with a ruthlessness that often ignored diplomatic privileges and foreign nationalities. Brunel had no choice but to escape France and leave Sophia behind. With the help of a friend, he obtained a passport that allowed him to travel to America for the purpose of obtaining wheat for the army. He boarded the American ship Liberty and sailed for New York. Brunel probably felt that he was now out of danger, but it was not to be. A French warship approached the Liberty and ordered her to heave to so that she could be searched for political refugees. Brunel could not find his passport. Stifling his panic, he took a pen, some paper, and scissors, and secreted himself in a remote hold of the ship. Brunel's drafting skills came to his rescue. It took two hours for the French officers to find him, but by then he had counterfeited a passport good enough to pass inspection. Even then, it had been a close call, since many officers in the French Navy knew the young man. The ship continued on its voyage to New York, and Brunel made sure not to lose his new “passport.”
Arriving in New York, Brunel saw to his horror that a squadron of French naval ships was docked in the harbor and the city's streets were crawling with French officers and seamen. Since the American government was then on friendly terms with France, an extradition request might have been honored. Or he just might be knocked on the head, taken onboard one of the French vessels, and put in chains to await the ship's return to France. Thus, Brunel had no choice but to flee New York. He went to Albany, hoping to find a friend, Pierre Pharoux (they were fellow passengers aboard the Liberty), who was then surveying the Black River Valley in upstate New York. He met up with Pharoux and became a member of his surveying party. Since Brunel's surveying skills were superior to Pharoux's, the latter cheerfully allowed him to take charge of these duties. This portion of the state was still largely unexplored, and the team depended on the goodwill of the local tribes to perform their work. Apparently Brunel made a good impression on the local Native Americans; fifty years later, Oneida tribesmen were still talking about a wonderful white man called “Bruné.”
At one point, John Thurman, a wealthy merchant with strong political connections, joined the surveying party. Thurman was interested in developing this remote part of New York and was naturally eager to know what areas held the best prospects for farming, lumbering, and road building. After spending some time with Brunel, he quickly recognized that the young man's surveying, architectural, and mechanical abilities were uniquely suited to the needs of the growing country. After the survey party had completed its assignment, Thurman used his influence to obtain work for the Frenchman, and it was not long before Brunel was receiving more commissions than he could accept. Relations between France and America were also souring, so he felt safe in applying for American citizenship, which he was quickly awarded. Brunel formed friendships with many prominent figures in the United States, including Alexander Hamilton and Pierre L'Enfant, the planner of the nation's new capital, Washington City. At L'Enfant's suggestion, Brunel submitted a design for the first Capitol building, which, while admired by the judges, lost out to another's plan. Through Hamilton's influence, Brunel was awarded the post of New York's chief engineer. While serving in this position, Brunel oversaw the construction of a number of buildings, built a cannon foundry, and supervised the fortifications of the Narrows at New York Harbor.
One day, Hamilton invited Brunel to his house for dinner. There, Hamilton introduced him to Pierre Delabigarre, another French political refugee who had come to America and become a citizen. Delabigarre told Brunel that the British Navy was having problems obtaining enough ship's pulley blocks, since each one had to be laboriously carved by hand. A single warship used up to fifteen hundred blocks, and the British Navy purchased over a hundred thousand blocks each year for new ships or to replace broken ones.
Brunel saw his opportunity. He was certain that he could design a machine that could mass-produce the blocks. Besides, he wanted very much to go to England. Britain was the heart of the new Industrial Revolution, where innumerable opportunities awaited talented and inventive individuals. America, on the other hand, was still a largely rural society and would remain so for a couple of generations to come.
Brunel had another reason for wanting to go to Britain. After his escape from France, Sophia had been arrested. Britain joined the European coalition fighting against the revolutionary government, which prompted the latter in October 1793 to pass a degree ordering the arrest of all British citizens residing in France. Sophia was also under suspicion for her relationship with a royalist “enemy of the State.” She languished in prison, existing on bread mixed with straw, and on several occasions barely avoided being sent to the guillotine. After Robespierre's overthrow and execution, a more moderate faction had come to power, and most political prisoners and British citizens, including Sophia, were released. Sophia left France for England, and Brunel wanted to join her in London.
Taking with him what money he had saved and letters of introduction from his prominent friends, Brunel sailed for England in 1799. Thankfully, it was a smooth voyage without incident. Arriving in London, Brunel was reunited with Sophia, and they soon married. Brunel's marriage would be the happy bedrock in his oft star-crossed life, for he would continue to live in “interesting times.”
His first two months in England were extraordinarily busy. Besides marrying Sophia, he worked on the designs for his block-making machine, took out a patent on a writing and duplicating device (possibly inspired by Thomas Jefferson's copying press), and invented a machine for twisting thread. By 1801, he had built a working model of his block-making machine with the assistance of the famed toolmaker and inventor Henry Maudslay. Brunel approached the firm of Fox and Taylor, which supplied the blocks to the British Navy, with his machine model. The company showed no interest, telling Brunel that it had spent many years perfecting its method of manufacturing blocks and saw no possibility that it could be improved upon. Brunel then took his plans to Lord Althorp (George Spencer), First Lord of the Admiralty, and Sir Samuel Bentham, the noted inventor and naval architect. The latter had been working on the same problem, but his equipment could produce only a rough block that needed to be finished by hand, while Brunel's device could perform all the manufacturing steps. At Bentham's recommendation, Brunel won the contract to provide blocks for the British Navy. Maudslay built the complicated machines, and the navy was soon receiving blocks at low prices and in large quantities. What had once required sixty men now required just six, and their output was incomparably higher. The factory was one of the earliest examples of mass production.
Things went smoothly for a time, but Brunel had difficulty obtaining payment from the admiralty for the blocks he was delivering to them. He had invested £2,000 of his money in the venture, yet he was seeing nothing in return. He finally received £1,000 “on account,” but six years would pass before he was sent a more substantial payment—£17,000—though it was still less than what was owed. (The British government's heartless and myopic penny-pinching ways would become legendary.) In the meantime, Brunel had patented some improvements to sawmill machinery. There was a big demand for lumber by the British Navy, which was now fighting Napoleon on the high seas. The war kept Brunel busy, but this time he just built the sawmills and let others deal with the government. His most notable effort was the steam-powered sawmill at Chatham, near its docks, which increased lumber output while reducing yearly manpower costs from £14,000 to £2,000.
Learning that the British Army needed thousands of boots, which, like the pulley blocks earlier, were made slowly by hand, Brunel designed and built machinery that could perform much of the laborious work—the earliest example of the mechanized mass production of shoe wear. Brunel obtained a contract for fifteen thousand boots of various sizes. He had just received his £17,000 for the blocks and had recently become a British subject, and so felt more comfortable about filling the government's order. Of course, after the boots were made, peace broke out, and the government informed him that they didn't need the boots after all. Not only was Brunel stuck with the boots, but he also needed to pay the suppliers who had provided him with the tons of leather and hobnails to make them. Granted, he had also made some unwise investments, but it was the affair with the boots that pushed him over the edge to insolvency. He petitioned the government for redress while holding off his creditors as best he could—for years—but it was all for naught, and he was sent to a debtors prison in 1821. Brunel, who had saved the government of his adopted country God knows how many pounds—although the Exchequer probably knew—now found himself behind bars.
Seeing no prospect for release, he started corresponding with the Russian tsar, Alexander I, who had earlier offered him a well-paid position at court overseeing various engineering projects. After describing his many “vexations,” Brunel suggested building a tunnel under the Neva River in St. Petersburg. As a young man in Rouen, Brunel had picked up a floating piece of wood and, noticing the telltale holes of a shipworm, took it apart to see how the creature could make its way through the hard cellulose fibers. The shipworm—actually a mollusk related to clams—possessed a small, two-piece tubular shell near its head that protected it while it bored through the wood. This gave Brunel the idea of a shield that could be used for tunneling purposes. This inspiration would later have important ramifications.
Brunel was universally well liked, and while he languished in prison, his many friends in high places were lobbying for his release. When the British government learned that it might lose one of its brightest subjects to the Russians, it cut a deal with Brunel. Essentially, it offered to pay off his debts if he agreed not to work for the tsar or for any other foreign government. It was a wise move, for Brunel was about to embark on a project that would bring fame to Britain and earn him knighthood. However, Brunel being Brunel, would not accomplish his goal without encountering some difficulties. These would remain interesting times for him.
The largest use of hydraulic cement since the days of ancient Rome was the construction of the Thames Tunnel in London. It was Ralph Dodd who first suggested building a tunnel underneath the Thames River in 1798. Dodd, an engineer from Northumberland who had observed coal miners excavating beneath the River Tyne without any apparent hazard, proposed a tunnel be built to connect the districts of Gravesend and Tilbury. One or two years later (some accounts give late 1799, others, early 1800), work began. A shaft was dug at the Gravesend side, but it continually filled with waterlogged sand. The project should have ceased as soon as it became clear that the ground was unsuitable for excavation, but Dodd believed he could work around the problems and persisted in his efforts until the funding eventually ran out two years later.
A new enterprise, the Thames Archway project, was created in 1804 to build a tunnel linking Rotherhithe and Limehouse (now Wapping). Robert Vazie, another Northumberland engineer, was chosen to supervise the effort. Though the ground was not as bad as that at Gravesend, Vazie also encountered flooding problems that continually put the tunnel project behind schedule. Frustrated with the slow progress, the directors hired Cornish engineer Richard Trevithik to replace Vazie. Trevithik was a gifted mechanical engineer who had made a number of improvements to steamengine technology. (He was one of the earliest advocates of steam-powered transportation and even built working examples to demonstrate the concept, but no one was interested in the scheme.) At the time he was offered the tunnel project, Trevithik was enjoying some popularity for the success of his steam-powered dredger, which was being used to keep the Thames waterway clear for shipping. The Archway Tunnel directors apparently thought that he was the right man to deal with mud. Trevithik hired a group of Cornish miners to build the tunnel, but the men, more used to dealing with rock than river slime, had difficulty adapting to the new conditions. Still, adapt they did, and work progressed steadily. In 1808, with the tunnel over two-thirds completed, a break in its ceiling caused a catastrophic flood that nearly killed Trevithik and several coworkers. A story persists that the flooding was caused in the following manner: someone told Trevithik that the tunnel was out of line and bearing slightly off course. Trevithik then reportedly broke through the tunnel's ceiling to take a look, and so caused its flooding. The story sounds like a malicious fable spread by one of Trevithik's colleagues, with whom he was always quarreling. One cannot read of Trevithik's accomplishments and at the same time believe he could do such a witless thing.
Undaunted, the Thames Archway project announced a public competition for proposals to build the tunnel. Charles Wyatt—of Parker and Wyatt fame—won the competition. He suggested that the Thames's riverbed be dredged along the proposed course of the tunnel. Into this trench, prefabricated brick cylinders—built using Wyatt and Parker's hydraulic Roman cement, of course—would then be laid and joined underwater. On paper, the scheme made sense, but when the company hired John Isaac Hawkins to test the viability of the proposal, the shifting riverbed and the difficulty of connecting the cylinders proved insurmountable. An engineering report later concluded that building a tunnel under the Thames was “impracticable,” though a close reading of the report suggests that the term “virtually impossible” was a better description. The Thames Archway Tunnel project came to an end.
Nevertheless, the idea of constructing a tunnel under the Thames stubbornly persisted. To talented and visionary individuals, nothing is more tempting than accepting a challenge to perform the impossible. And Brunel wanted to do just that. Perhaps no one since John Smeaton was as capable—and stubborn enough—to tackle such a formidable project.
Brunel approached investors with his tunnel-shield idea for excavating under the Thames. The previous two tunnels were cramped, three-feet-wide (ca. 91 cm) pedestrian passageways that barely allowed two people to pass each other. Brunel's tunnel would be more massive: twenty feet high and thirty-five feet wide, consisting of two parallel arched corridors open to each other and large enough to permit both foot traffic and carriages. Brunel provided detailed drawings of his proposed “tunnel shield” that would protect the workers and secure the excavation effort as it progressed. He described the shield as an “ambulatory coffer-dam.” The investors were interested enough to pay for a series of test borings of the Thames's river bottom, and the best results came from the borings performed between the banks of Rotherhithe and Wapping, less than a mile from Trevithik's tunnel. Here, the borings pulled up firm “blue clay.” Convinced that Brunel's plan was practical, the Thames Tunnel Company was incorporated in June 1824, and 2,128 shares were issued at £50 each. Once the tunnel was completed, the shareholders believed that a small toll would eventually cover the costs of construction and thereafter provide a steady income.
Work began in Rotherhithe on March 2, 1825, a little over a hundred feet from the banks of the Thames. A vertical shaft had to be excavated down to the desired depth before work could proceed on the tunnel proper. Brunel handled this in an ingenious fashion: he had a fifty-foot-wide, flat iron ring assembled on the spot where the shaft was to be excavated. Upon the ring, he constructed a circular brick tower using Roman cement. The brick walls were built several wythes (layers) thick, and the tower's interior was strongly braced by wooden timbers and iron tie rods. As the walls of the tower rose, the workmen dug out the earth within. As the excavation progressed, so did the tower's height and weight, and the structure slowly began sinking into the ground. Once the masonry was finished, a steam engine was assembled on top of the tower. The engine was used to pump out the water that sometimes flooded the hole and operate a conveyor that carried up the endless chain of buckets filled with excavated earth that needed to be dumped (the men had previously been handling that task by climbing ladders, buckets in hand). Gradually, despite minor setbacks, the tower sank to the desired depth of 65 ft (ca. 20 m). The vertical shaft was completed in November 1825. Now it was time for the horizontal excavation work to begin using Brunel's shield.
Or maybe not. The chairman of the tunnel project, William Smith, seemed intent on undermining Brunel at every step. As the tower began sinking and Brunel was finishing up the final details of the tunnel shield's design, Smith got cold feet. He told Brunel that the shield was an unnecessary luxury and that the tunnel could be constructed using more traditional methods. Brunel pointed out the failure of these conventional approaches in the previous tunneling attempts. Smith held to his position, while Brunel went ahead and ordered the shield's construction (it would be built by his old friend, Henry Maudslay). Since a shield was in the original plans—and its maker, Maudslay, was now famous and politically well connected—Smith gave in. Smith was a Member of Parliament and astute at recognizing the limits of how far he could obstruct Brunel—not that he ever gave up trying.
Maudslay delivered the several hundred cast iron and wrought iron components that made up the tunnel shield to the worksite at Rotherhithe. Each was lowered by crane to the bottom of the shaft to be assembled. Once the shield was put together, it was rightly considered an engineering wonder. The eighty-ton behemoth consisted of twelve frames, aligned vertically to one another, and each contained three compartments where the men could excavate the earth ahead of the masonry work. Every frame held dozens of poling boards—five hundred in all—that penetrated the face of the tunnel, called the “drift,” several feet in depth. These poles served to both hold the frame in place and help loosen the clay soil ahead. Each frame, supported at its base by a broad iron shoe connected by a ball joint, could be moved forward by powerful screw jacks that abutted the brickwork to better follow the progress of the various labor teams. Of course, this inspired a lively competition, so no one frame advanced much beyond any of its companions. The shield began its slow journey north to Wapping on November 25, 1825.
As work started on the horizontal shaft, Smith and Brunel began arguing over which Roman cement to use. Brunel wanted to use Francis & White's Roman cement, while Smith insisted that a cheaper alternative be used, one produced by a friend, Matthew Wilkes, an immensely wealthy businessman. Wilkes had also seized the opportunity to open a cement works after the expiration of Parker and Wyatt's patent and was aggressively peddling his product. There is no evidence of Wilkes having bribed Smith, but it would not have been surprising, since Wilkes had an unsavory reputation (he had made his fortune from pirating and the slave trade). Brunel had not liked using Wilkes's inferior cement on the tower, but now that excavation was beginning under the Thames, he insisted on the one manufactured by Francis & White, pointing to tests he had conducted that showed it to have better hydraulic properties. The chairman would not budge until Brunel's incessant complaints and letters made the issue too tiresome to contest, so Smith finally allowed the engineer to use his favorite cement. (Smith and Wilkes must have enjoyed some satisfaction when, later, a barge carrying a large quantity of Francis & White's cement to the worksite sank in the Thames, a misfortune ascribed to an accident.)
Still, Brunel realized that just one batch of defective cement could jeopardize the entire enterprise, and he required that a sample be taken from each cask and tested—a practice that many years later would become standard in the construction industry. Four hundred samples were tested each week, which means that hundreds of tons of cement—probably representing close to half of Francis & White's total production—were being used each month to mortar the five-wythe-thick brick walls of the tunnel.
Water was more of a problem than originally expected. The cheery results of the borings proved deceptive, for while the soil was mostly clay, it was also veined with water passages and sometimes pocketed by huge cavities filled with water-soaked mud. Both mud and clay were inundated by the detritus of centuries, and the tunnelers occasionally plucked the odd artifact out of the slime. However, it was the more recent rubbish that proved more troublesome, and the tunnel often stank of the still-decaying garbage that dropped down from the ceiling or popped out from the drift. This slimy, coagulated waste generated methane that made the men dizzy or detonated the occasional “flashes” that singed hair or eyelashes. Fortunately, the quantity of gas produced was never high enough to cause a major explosion.
It was not only the workmen who were suffering from the poor air. Brunel and the other engineers were also laid low by the fumes. One of the assistant engineers, a man named Riley, fainted and was carried out of the tunnel. He became feverish, then delirious, and a week later he slipped into a coma and died. It is not certain whether the man had died from the gas or simply succumbed to one of the innumerable diseases that Victorian medicine was powerless to challenge, but most men at the worksite attributed Riley's death to the “bad air.” (The only other fatality up to this time had been a drunken worker who had fallen from the shield and landed on his skull.) Soon after Riley's death, Brunel was afflicted as well, writing in his diary that a “peculiar and indescribable sensation came over me—a haze rose before my eyes, and, in the course of half an hour, I had lost the sight of my left eye.”26 He was forced to spend several weeks recuperating, but he grew restless and returned to the tunnel works, even though his sight remained weak. When the resident engineer William Armstrong fell ill and seemed reluctant to return to work, Brunel appointed his young son, Isambard Kingdom Brunel, to replace him. Isambard, who had been working as an assistant engineer on the tunnel project since its beginnings, had just turned twenty. Despite the nepotism involved, it was a good choice. Isambard was every bit as brilliant as his father and would one day eclipse the fame of Brunel père.
Based on the borings, Brunel had estimated that the tunneling work would proceed at three feet each day, but with the ground proving at times to be more liquid than solid, he was lucky to move just one. He asked that a spillway be constructed to evacuate the water, but Smith and the directors said that it would be too expensive to build, so men were forced to work hand pumps and carry water buckets from the flooded gap between the brickwork and the shield (steam-powered pumping was now impractical with the tunnel so deep). Although it was a decision the directors would soon regret, Brunel had grown tired of fighting Smith, and so the spillway was not built. Nevertheless, the prospect of catastrophic flooding, though often unspoken, remained lodged in everyone's mind. On January 4,1827, Brunel wrote in his diary, “Every morning I say, ‘Another day of danger is over!'”27
By March, the amount of water coming in between the shield and the brickwork steadily increased, and so did the appearance of sundry items in the mud that were clearly of more recent origin, such as broken pieces of contemporary porcelain, barely corroded nails, and shipping tackle. These bits of newer rubbish gave Brunel some concern, but all the 1825 borings had shown that a thick level of gravel overlaid the mud and clay of the river bottom, and earlier measurements had indicated that the tunnel was at least twenty feet below the latter. If they were close to the Thames's bottom, gravel would have washed in with the water. All the engineers agreed that the appearance of gravel was a dangerous sign, but so far it had not been in evidence.
The volume of water seepage continued to grow. Now forty men were working the pumps full-time and carrying buckets back to the vertical shaft. The additional manpower expense easily offset the cost of Brunel's proposed spillway. The water also put everyone's nerves on edge. The brick foremen, who took naps near the shield, began shouting in his sleep that the tunnel was flooding. A brief panic followed until one of his coworkers realized what was happening and woke him up.
Still, both the men and the engineers continued to have forebodings. One day, while Isambard Brunel was having breakfast, a workman ran from the shaft, shouting, “It's all over, it's all over, the river's in and they're all drowned except one.” Isambard and his assistant, William Gravatt, dashed down the shaft and ran to the drift-work. They found only a wet lump of clay that had fallen from the ceiling of the shield. The high-strung tunneler was fired. Nevertheless, the threat of flooding, however real, was always at the drift and not from the brick walls, which, thanks to Francis & White's cement, remained watertight.
By April 1827, the amount of water coming into the works increased, and though the leakage was still manageable, it troubled Brunel. After much pestering, Brunel was able to convince the directors to hire a diving bell to explore the river bottom. Isambard and Gravatt volunteered for this hazardous task, but both men had to steel themselves before venturing into the bell, which was then hoisted upward by a heavy crane bolted to a ship especially designed for managing the device. The bell rocked back and forth, jostling the men as the crane positioned it over the water before lowering it into the murky depths of the Thames. It was probably the earliest instance of a diving bell—a recently invented device previously restricted to salvage operations—being used in a major civil engineering project. Isambard and Gravatt sat on a small seat positioned between two thick glass windows on each side of the bell, which was more tubular than spherical. The bell's bottom was open, and the air within was held in place by its own pressure. Of course, if the bell hit an obstruction that tipped it over, its occupants would be in trouble. As the bell descended and approached the river bottom, the men could see why so much water was now entering the tunnel. Trevithik's steam-powered dredgers, which had been employed earlier to clear the Thames's waterway for shipping, were now being used to harvest gravel. A deep depression had been scooped out of the river bottom directly above the tunnel. Probing the base of the depression with an iron rod, Isambard soon struck the top of the shield. Isambard realized that something needed to be done quickly to protect the tunnel.
A hard lining called a “steening” was prepared, by which the exposed earthen walls between the brickwork and the shield were reinforced with a layer of Roman cement concrete. The seeping water activated the fast-setting properties of the cement, and the seal seemed to hold. The leakage around the gap dropped somewhat, but the water, following the path of least resistance, began permeating through the small gaps of the shield itself, especially where the poling boards penetrated the drift. The men in the lower chambers of the frames often found themselves working knee-deep in water or fetid muck.
By early 1827, the directors—and Brunel—were getting nervous, as the funds allocated for the project were running low. Since there was much curiosity about the tunnel, the directors decided to raise money by charging people one shilling apiece for a tour of the works. Commoners and aristocrats rubbed shoulders to watch the progress, and all agreed that it was a remarkable endeavor that, once completed, would be an engineering triumph for Britain. Another possible motive for the tour was that the directors wanted to cultivate potential investors to refill the kitty. The shield was now so far from the Rotherhithe end as to look like but a dot in the distance. Evidently, the directors hoped that visitors would instead take notice of the tunnel's magnificent archways and not the mess the men were working through at its terminus. Higher-class visitors, who were viewed as potential investors, were given a complete tour of the works, including Brunel's tunnel shield. Unfortunately, the visitors proved to be more trouble than they were worth. The laborers had to work around them, being especially careful not to splash mud or water on the guests' clothes as they carried buckets back to the vertical shaft. No new investors were recruited. As for the tour fees, less than a hundred pounds were realized from them.28
By mid-May 1827, 540 feet of the tunnel had been completed, almost half its projected length of 1,296 feet. Brunel's shield, aided by the concrete lining, was now steadily advancing a foot or more each day. While this was far less than his original estimates, it was better than it had been for many past months. On May 13, Brunel wrote in his diary, “So far the shield has triumphed over immense obstacles, and it will carry the tunnel through.” In an entry Brunel scribbled later the same day—perhaps after remembering his checkered fortunes—he expressed worries: “[A] disaster may still occur. May it not be when the arch is full of visitors! It is too awful to think of it!”29
A few days later, as Brunel was giving a tour to Lady Sophia Raffles—wife of Sir Thomas Stamford Raffles, founder of Singapore—and a group of her friends, water began leaking from frame No. 11, not an unusual occurrence, but still troubling. Brunel would write later that he was “most uneasy all the while, as if I had a presentiment.” After Brunel escorted Lady Raffles and her entourage out of the tunnel, one of the assistant engineers, Richard Beamish, noticed the leak and tried to staunch the flow. The water quickly began pouring out at an alarming rate and then become a torrent. A tunneler grabbed Beamish's arm and shouted, “Come away, sir, come away; ‘tis no use, the water's rising fast.” The other workmen, who had already begun running toward the staircase at the end of the tunnel, now found themselves propelled as much by the roaring water behind them as by their feet. A wooden office that was positioned one hundred feet from the shield was picked up bodily by a wave and, accompanied by hundreds of empty cement casks, formed a treacherous flotsam. The flood doused all the gas lamps in the tunnel, and men now struggled in the dark to reach the exit before it was too late.30
Aboveground, near the shaft, Isambard was going over some paperwork with Gravatt when they heard noise coming from the tunnel and saw men pouring out. Gravatt wrote that young Brunel immediately ran toward the works, and he quickly followed, but they could not get down the stairs because of the press of retreating workers. Gravatt encountered one tunneler who said that it was “all over.” Gravatt, remembering the earlier false panic, called the man a coward but then recognized the true extent of the calamity when he saw water begin rising up the vertical shaft. The laborers climbing the staircase inexplicably stopped to look at the rising water, as if mesmerized by it; one later described it as “splendid beyond description.”31 Isambard shouted orders at the men to keep moving with all speed. This seemed to snap them out of their spell, and they began scrambling upward again. Gravatt recounted that they saw a man “in the water like a rat” and “quite spent” clutching the stairway's handrail, unable to go further. “I was looking how to get down, when I saw Brunel [Isambard] descending by rope to his assistance. I got hold of one of the iron ties, and slid into the water hand over hand with a small rope, and tried to make it fast round his middle, whilst Brunel was doing the same. Having done it he called out, ‘Haul up.' The man was hauled up. I swam about to see where to land. The shaft was full of casks. Brunel was swimming too.”32 Isambard and Gravatt were finally able to make it to the top of the shaft and were the last ones out of the flooded tunnel works.
By some miracle, no one was killed.
Two days later, Isambard hired the diving bell again to inspect the river bottom. He soon saw that the concave depression in the river bottom had deepened. This time it was not due to the dredgers; the intense tidal flows in the Thames were now scouring out a depression. Brunel did not need to probe with a rod to find the shield, for it was now partially sticking out. At one point, he took off his shoe, pulled up this pants sleeve, immersed one leg into the water, and could actually feel the cold, hard iron of the shield with his foot. He and his father had already discussed what course to take, and the previous twenty-four hours had seen the uninjured members of the tunneling crew filling thousands of cloth bags with clay, which were then packed on a flat barge that was now anchored above the shield. Back aboard the diving bell's ship, Isambard ordered that all the bags be dumped in the depression. The dumping continued for weeks, during which time Isambard made repeated trips with the diving bell to supervise the effort. It took approximately twenty thousand cubic feet of clay to fill in the depression and stop the leak. Now the pumping began. By this time, Brunel, who, like his son, had been working throughout the crisis with little sleep, turned over his duties to Isambard. The details are sketchy, but it seems that the elder Brunel may have had a mild nervous breakdown compounded by exhaustion or vice versa.33
After the pumping had lowered the water level in the tunnel by several feet, Isambard and his assisting engineers boarded a small dingy and rowed down the flooded corridor to inspect the damage. Because of the huge volume of mud that had been deposited by the flooding, the water became too shallow for rowing after several hundred feet. The men had to abandon their oars and began pressing their hands against the tunnel's ceiling to propel themselves forward. When the boat could no longer be moved, they used their lamps to look around. Just ahead they saw that the mud had risen above the waterline but seemed to level off a couple of feet beneath the tunnel ceiling. Gravatt took a lamp and left the boat to test the consistency of the mud. It seemed just solid enough to support the weight of one man. Gravatt crawled one hundred and twenty feet across the mud before reaching the shield. Here he could see the tops of several frames, pushed back from the steening and, just above, the bags of clay that had been used to stop the breach. After the men had returned to the vertical shaft and Brunel made his report, two of the company's directors expressed their wish to also survey the damage. Gravatt and several men escorted them down the tunnel in the dingy. At some point, the boat was capsized when one of the directors stood up to change positions with another. One of the directors, who could not swim, drowned.
Once the water had been pumped out, the mud carried away, and the shield put back into place, the tunneling work resumed. A celebratory dinner was held in the tunnel on November 10, 1827. In one passageway, the directors and tunnel investors dined to music played by the military band of the Royal Coldstream Guards, while in the adjoining passageway, the common laborers feasted on less exalted fare and drank grog. Spirits were high, and most of the directors were optimistic about their chances of obtaining the additional funding to complete the project. Most London newspapers had favorably covered the pumping and excavation operations, pronouncing it a triumph of British ingenuity. Even the sniping reporters had mostly stopped calling Marc Brunel “Monsieur Brunel” and begun referring to him instead as “Mister Brunel.” This was a personal and psychological victory for the engineer, whose loyalty to Britain—and competency in English—surpassed most of his compatriots. As he was still recovering from exhaustion and spent nerves, the elder Brunel did not attend the dinner. Nevertheless, he was buoyed by the resumption of tunneling operations and the positive press coverage it was given. His spirits began to revive, and soon he was back at the tunnel overseeing its operations at his son's side. The future looked rosy.
Progress slowed again, for the frames of the shield kept going out of alignment or sinking into the mud. The frames had to be jacked up, while men rammed in gravel and oakum (loosely twisted fiber) underneath them. The “bad air” also returned. When the ventilator failed, men collapsed and once again had to be carried out. Isambard and the engineers also suffered from the “vapors,” since they spent as much time at the tunnel works as any of the workers. Still, there was room for optimism: improvements were made to the ventilator, and, as the men grew used to making adjustments to the frames, the work took less time, and it appeared as if the excavation might resume its old pace.
Then Nature intervened with a vengeance. Unusually high rainfall that winter caused the Thames to rise, and by January 1828, the river surpassed its previous high-water mark by three feet and flooded portions of London. The high water levels also increased the weight of the river by millions of tons, exerting tremendous pressure on its bed below and on the tunnel works beneath it. On January 12, 1828, the water of the Thames broke through to the construction site. The water smashed its way in between the brickwork and No. 1 frame, ejecting a massive high-speed torrent like a colossal fire hose. The gaslights were instantly doused, and in the darkness the men could feel the water rising around them at a faster pace than had the previous irruption. The panicked men made another mad rush for the vertical shaft, and this time, Isambard Brunel was among them. The water rose so fast that the men at the back of the crowded mass making for the exits were forced to swim. Isambard was trying to help two of his assistants, Ball and Collins, when a huge wave knocked him down and carried him forward. When Isambard came up for air, he found that the swell had brought him down to the vertical shaft, next to the stairway. He grabbed onto it and shouted down the flooded tunnel, “Ball! Ball! Collins! Collins!” The water was rising fast. Tunnelers pulled young Brunel up and prodded him up the stairs, but he could hardly walk, having thrown the ball-joint of his knee, and so, hopping on one foot, he was half-carried to the top of the shaft. Aboveground, a blanket was thrown over the shivering Isambard, who sat down and, in a daze, continually repeated the men's names. Besides Ball and Collins, four other men drowned in the disaster, and many were injured. When a doctor examined Isambard, internal injuries were discovered as well. The young man would be confined to bed for the next several months. Marc Brunel was once again in charge.34
Once more, thousands of bags of clay were dumped into the Thames to cover the breach. The tunnel was pumped out a second time, and another mass of muck was again shoveled into buckets that were carried out by hand. This time, however, there was no resumption of work. Funds for the project had been exhausted, and so, in August 1828, the far end of the tunnel was bricked up. Sealed behind the masonry was the enormous iron shield. The pioneering device, once justifiably touted as an engineering marvel, was left to corrode.
To more than a few people, the project seemed over. The enormous construction effort that had been said to be impossible apparently proved to be just that. Yet, it would not go away. There was a collective sense of injured pride. It seemed out of character for the British to simply surrender to the elements and say, “Well, we gave it a good shot, but it was just too much for us.” In short, a large number of people, including many prominent lords and MPs, felt that it was shameful to give up on the Thames Tunnel project, and they began appealing for the nation to step in and finance its completion. Resolutions were passed, and it was not long before negotiations began between the project directors and the government for a loan. Of course, it's best not to hold one's breath while negotiating with a government. Talks dragged on, broke off, and resumed again in the same sluggish manner. William Smith was finally removed as president, a development that must have given Brunel some joy. Years passed. Finally, in December 1834, a deal was struck. The government agreed to a loan of £247,000. This, combined with money raised from other sources, allowed the construction work to begin anew.
Work began in August 1835 with the dismantling of the old shield, no easy task, since some of its constituent parts had now fused together from rust. Once the shield was removed, Brunel's new and improved tunnel shield was installed, and excavation work resumed in March 1836. Five months later, on August 23, the tunnel flooded again. The breach was stopped, the tunnel was pumped out and cleared, and work continued. Brunel's poor health impeded his supervision of the tunnel project's work, and after the August flooding, his nerves were shot as well. He resigned and turned the work over to his assistant engineer, Mr. Gordon. (Isambard was now engaged in other engineering projects.) The air in the tunnel affected Gordon's health as well, and he soon turned the supervisory work to a Mr. Page. Shortly after the tunneling work had recommenced, another flood stopped operations on November 3, 1837. After this disaster had been cleaned up, work continued before another subfluvian deluge on March 20, 1838, stopped operations once more.
The tunnel project was becoming a joke. Numerous doggerels were repeated, including this one:
Good Monsieur Brunel
Let misanthropy tell
That your work, half complete, is begun ill;
Heed them not, bore away
Through gravel and clay,
Nor doubt the success of your Tunnel.
That very mishap,
When the Thames forced a gap,
And made it fit haunt for an otter,
Has proved that your scheme
Is no catchpenny dream;—
They can't say “twill never hold water”35
The great engineer usually addressed as “Mister Brunel,” was now being referred to as “Monsieur Brunel” once again, as if to emphasize his foreign origins, the implication being that a British-born engineer would have performed better—though three British-born engineers had already tried and failed miserably to construct a tunnel under the Thames.
After the damage of the March flood was cleaned up, work progressed for two years without another flooding incident, but only very slowly. Apparently, there was more refuse dumping on the Wapping side of the Thames, for the methane leakages increased. Particularly dreaded was the “black mud,” an organic waste in its latter stages that always brought with it more gas than usual. The ventilator helped, but when it failed one day, men dropped like flies and had to be carried out of the tunnel. The directors finally agreed to restrict the men's hours in the tunnel to allow their lungs to recover.
On April 3, 1840, when the tunnel had almost reached the point that marked the far bank of the Thames, the water rushed in once more. Thanks to improved safety measures and the new shield—which slowed the flooding enough to give the men a chance to escape—only one laborer was killed in the flooding. The flood of April 1840 was the last, for the tunnelers were soon beyond the far bank of the river, and the mercurial Thames was no longer above them.
While the work continued at a slow pace—pockets of methane still caused fainting among the men or erupted in flashes—everyone was now confident that the worst of it was over. The sniping satires had stopped, and people began once more calling the tunnel's architect and engineer Mister Brunel. After March 24, 1841, even this form of address would not suffice, for on that day a young Queen Victoria knighted Brunel at the Rotherhithe construction site next to the tunnel's entrance. He was now Sir Marc. It was the crowning moment of a long, difficult, star-crossed career.
A few months later, Brunel suffered a stroke that paralyzed the right side of his body. He had to spend the following year convalescing and attempting to exercise his stiff limbs, but he continued to receive reports on the tunnel's progress and offer his advice. The tunnel reached the vertical shaft at Wapping on August 1, 1842, but another eighteen months were spent outfitting it with gas lines, lamps, and building the elaborate public staircases in the shafts at each end. The Thames Tunnel was finally opened to the public on March 25, 1843, to wide acclaim and celebration. Despite his ill health—the right side of his body was still partially paralyzed—Brunel attended the opening ceremonies. In the next fifteen months, over one million people would visit the first tunnel constructed under a navigable river.
Because of Brunel's age and the effects of the stroke, the Thames Tunnel would be his last project. He still consulted on engineering matters and especially enjoyed giving advice to Isambard, who was now one of the most noted engineers in Britain. Brunel's “interesting times” were over at last. He spent the last few years of his life with Sophia, content with his past achievements and enjoying the autumnal glow of a glory that took several difficult decades to achieve. On December 12, 1849, Sir Marc died at his home in London. He was eighty years old. He was buried at Kensal Green Cemetery, where Sophia would later join him, and, later still, his son, the now-famous engineer Isambard Kingdom Brunel. It is supremely satisfying to recount the life and career of a remarkable man and to see it conclude with a “happy ending.”
The original plans for the Thames Tunnel called for a gentle slope at each end to allow carriages to pass through, but there was not enough funding left to purchase the additional real estate and build the roadway. It remained an overlarge pedestrian corridor, where people bought trifling souvenirs and were entertained by organ grinders, fortune-tellers, and—in the evening—the occasional prostitute. In 1865, the East London Railway Company purchased the tunnel to serve as an underground conduit linking rail service between Rotherhithe and Wapping. It now forms a small part of the London Underground network.
The Thames Tunnel would have been inconceivable without the use of concrete cement, and during the eighteen years of construction, the material had undergone some changes and refinements. The quality of most Roman cements was variable—one reason why Brunel tested every batch. Even if one commercial source was more trusted than another, slight differences in the setting periods or hydraulic properties could cause problems on the worksite. The search for a better and more stable material would eventually bring an end to the use of Roman cement and see the rise of its replacement: Portland cement.
On October 21, 1824, a struggling forty-four-year-old bricklayer in Leeds named Joseph Aspdin was granted a patent, BP 5022, for a hydraulic mortar/stucco he called “Portland Cement.” Exactly one hundred years later, representatives of the British Cement Makers Federation and the American Portland Cement Association unveiled a plaque in Leeds commemorating the event. Speeches were given that recounted the enormous contribution this “humble bricklayer” had made to human progress and how he made possible the benefits we enjoy today. In virtually every chronicle of concrete's development, Joseph Aspdin is portrayed as having played a leading role in the material's advance. In Kendall F. Haven's book 100 Greatest Science Inventions?36 Joseph Aspdin's invention of Portland cement is ranked among those revered one hundred (his contribution is listed between Archimedes's compound pulley and Charles Babbage's analog computer). In truth, it is highly unlikely that Aspdin personally contributed much of anything to the development of modern concrete. It is probable that those august officials from the British and American cement industries had dedicated the plaque to the wrong person for the wrong reasons. Few discoveries in the Industrial Age are shrouded in so much mystery—or obscured by so many deliberate fabrications—as Joseph Aspdin's “invention” of Portland cement. However, enough information has been uncovered to tease out some details. And the leading candidate for the invention of Portland cement is not Joseph Aspdin.
The details of Joseph Aspdin's life are very spotty. He was born in Leeds sometime in late 1788 (the exact date has been lost) to bricklayer Thomas Aspdin and his wife (whose name has also been lost to us). Since he was baptized on Christmas day of that year, it is assumed that he was born earlier that month. Joseph was the firstborn of the Aspdins' six children. He grew up in a crowded and struggling household, but his father was kept busy at his craft: Leeds was undergoing significant growth in the late eighteenth century. It had long since become the nexus of Britain's wool industry, and the recent introduction of the mechanized spinning and looming devices made Leeds the textile capital of Britain. Since virtually all the massive factories that were then popping up in Leeds were built of brick, a bricklayer could expect steady, if meagerly paid, employment. As was common in those days, the sons took up the father's profession, and Joseph became a bricklayer.
On May 21, 1811, at the relatively ripe age of thirty-one, Joseph married Mary Fotherby. The marriage certificate states his occupation as “bricklayer,” a profession that he had probably been practicing since at least his fourteenth birthday. By late 1816, he had his own business and address, for the 1817 Leeds directory lists him as “Joseph Aspden. Bricklayer. Ship-In Yard, Back of Shambles.”
The misspelling of his name was probably a typo, and not due to Aspdin's ignorance: many bricklayers were either illiterate or barely literate, but Aspdin seems to have had enough schooling to read and write decently. By this time, Aspdin was the father of several children, one of whom, William, would play an important role in concrete's story. There is no question that Joseph Aspdin possessed some ambition and curiosity, for he was obviously conducting experiments with different cement formulas for several years prior to his patent application. These experiments were probably hard for Aspdin to conduct, since there was no local source of limestone, and rail transport had yet to be introduced. Adding to this difficulty was another problem: bricklayers employed in the construction of a residence or factory were provided with a fixed amount of mortar, the use of which was overseen by a sharp-eyed foreman. It was not uncommon for bricklayers to mix too much sand in the mortar so they could squirrel away a portion of the hydrated lime for their own use. Thus, there was only one place where a poor—or tightfisted—person in Leeds could obtain limestone: paved roads. Aspdin was twice fined for pilfering limestone from the highways of West Yorkshire. For every time he was caught, Aspdin had no doubt made a dozen successful plunderings, so he could probably afford the penalties.
Aspdin's experiments did produce cement that he felt was worth patenting. The relevant portions of the patent are provided below.
My method of making a cement or artificial stone for stuccoing buildings, waterworks, cisterns, or any other purpose to which it may be applicable (and which I call Portland cement) is as follows:—I take a specific quantity of limestone, such as that generally used for making or repairing roads, and I take it from the roads after it is reduced to a puddle or powder; but if I cannot procure a sufficient quantity of the above from the roads, I obtain the limestone itself, and I cause the puddle or powder, or the limestone, as the case may be, to be calcined. I then take a specific quantity of argillaceous earth or clay, and mix them with water to a state approaching impalpability, either by manual labour or machinery. After this proceeding I put the above mixture into a slip pan for evaporation, either by heat of the sun or by submitting it to the action of fire or steam conveyed in flues or pipe under or near the pan till the water is entirely evaporated. Then I brake the said mixture into suitable lumps and calcine them in a furnace similar to a lime kiln till the carbonic acid is entirely expelled. The mixture so calcined is to be ground, beat, or rolled to a fine powder, and is then in a fit state for making cement or artificial stone. This powder is to be mixed with a sufficient quantity of water to bring it into the consistency of mortar, and thus applied to the purposes wanted.37
The guileless, semiconfessional part about obtaining the limestone is a hoot, but let us move on to examine exactly what Aspdin was describing. He was taking good, pure limestone and grinding it to a powder form that he then kilned. On the other hand, he may have lost the explicatory thread of his tortuous description and mentioned the powder part prematurely. Perhaps he meant to say that he broke the limestone into pieces small enough to kiln easily, after which he reduced them to a powder. (The other way would have been far more difficult and might have fused the fine particles during the firing.) There may have been another reason for this strange description. It was not uncommon for inventors back then to deliberately falsify an ingredient or aspect of the manufacturing process to protect themselves from imitators. Aspdin goes on to relate how he takes clay and mixes it with water and then dries it until the “water is entirely evaporated.” Further obscuring both his intentions—and chemical logic—Aspdin goes on to kiln the “said mixture” until it reaches a state in which it can be “ground, beat, or rolled” into a powder and used for cement. Again, Aspdin has either lost the thread of his description or is being deliberately vague, for nowhere does he mention mixing the lime with “dried” clay. One assumes he has, since he kilns the mixture until the “carbonic acid is entirely expelled,” which points to limestone being involved. (References to carbonic acid are common in nineteenth-century mortar patents, and simply point to the then-imperfect understanding of how calcium carbonate was transformed to calcium oxide.) But this also makes no sense, since he has already calcined the powdered (or chunks of) limestone, and so completed the removal of the “carbonic acid.” Most likely he thought that the second kilning removed even more of the “acid,” but, of course, there was none. As we have already seen, the patent clerks of the early nineteenth century were either overworked or slow on the uptake when it came to basic chemical processes, or perhaps both. Lime-based cement patents were being filed left and right during this period. The clerk who approved Aspdin's application probably thought, “Oh, no! Not another patent for a cement mortar and stucco!” and probably did not read the document carefully before registering it, which was common at the time.
The importance given to Aspdin's patent is principally due to several reasons: reading more into the text than what was there, ignorance of the work being done by others at the same time, false information promulgated later about Aspdin's product by another party, and, of course, the designation “Portland cement,” which later became the name for standard modern concrete cement.
Later authorities, looking at the patent after many years of technological progress in cement manufacturing—and flawed accounts of Aspdin's methods—interpreted it in such a way as to construe a step in the production process that was not really in the text. This requires a brief explanation. After Roman cement became popular as mortar and stucco, many people tried to make it better in some way, or they pretended that their version was better—oil stucco being one example of many failed attempts. However, two discoveries in the first half of the nineteenth century did improve the quality of cement. One enhanced the material marginally, while the other represents a significant advancement in cement technology. The first was a process we will call “slurry mixing,” the ancestor of today's “wet process” of cement mixing. Slurry mixing was probably developed previously—much is murky during this period—by two other Englishmen, James Frost38 and Edgar Dobbs.39 To control the right proportions of clay and limestone, and at the same time strengthen the bond between them, the powdered limestone—still unkilned—was thoroughly mixed with clay and water, and the whole was allowed to dry until it assumed a paste-like form. This paste was cut into portions small enough to kiln. After kilning, the cooked pieces were then pulverized to make cement. The second critical discovery—dependent on the first—was something called “clinkering.” Cement makers using the slurry-mixing process were careful not to “overcook” the mixture in the kiln. If the mix was kilned too long, the resulting material was completely vitrified. In other words, it would become a hard, rock-like substance, called “clinker,” which was very difficult to pulverize. Over-burned and blackened bricks that could not be sold were also called clinkers, and this is probably where it got its name. Cement clinkers were also deemed useless and tossed away, since the cement manufacturers wanted an easily pulverized product. If they had taken the trouble to grind up the clinkers—and admittedly this would have cut down the life span of millstones significantly—they would have discovered the finest cement the world had yet seen. While slurry mixing might be read into Aspdin's patent, nothing suggests that he discovered the wonders of clinkering. If he had, it definitely would have been noticed by his competitors and others, for it would have stood head-and-shoulders above anyone else's cement.
As for the name Portland cement, it was hardly novel. Years earlier, John Smeaton remarked that his hydraulic mortar set as hard as “Portland stone,”40 the famed limestone used in the construction of many prominent buildings. And at least one other cement manufacturer, William Lockwood, was manufacturing a fine product he called “Portland cement”41 several years prior to Joseph Aspdin's patent being granted.
So why has so much attention been paid to this particular patent filed by an obscure bricklayer and cement maker? For that we have to thank Joseph Aspdin's son, William. It can be argued that no single individual has contributed so much to the history of concrete—or so corrupted that history—as William Aspdin. Sadly, corruption was an inextricable component of William Aspdin's character.
William Aspdin was born on September 23, 1815, in Leeds. In 1825, he and his family moved to Wakefield, just south of Leeds. His father had formed a partnership with William Beverley, and the two had built a cement works there. Beverley, who owned a successful brass foundry in Leeds, capitalized the venture. Joseph Aspdin was allowed to manage the cement works in Wakefield, while Beverley remained in Leeds to serve as their commercial agent. Wakefield was probably chosen because land and labor were cheaper there than in burgeoning Leeds. Sometime around late 1829 or early 1830, William began work at the cement facility as an apprentice. Things did not go well at Wakefield. Assuming that Joseph Aspdin was slurry-mixing the cement—a more expensive procedure than simply burning the clay-adulterated limestone to produce Roman cement—he would have found it difficult to compete against rivals who offered a cheaper product. Slurry mixing might have made Aspdin's cement slightly better, but consumers probably balked at having to pay for this marginal improvement. Besides, Roman cement had proved itself, while the claims for “Portland cement” were based on the attestation of its maker and not on any independent tests. To remain competitive, Joseph Aspdin almost certainly provided both Roman cement and his Portland cement.
In any event, Beverley was probably anxious about the venture by the mid-1830s. His foundry had prospered—he now had an iron works as well—but the same could not be said of his cement division. When the newly formed Manchester & Leeds Railway presented a plan in 1837 that showed a route running through the Wakefield cement factory, he decided to dissolve his partnership with Joseph Aspdin. Aspdin was forced to disassemble his kiln and relocate it to a nearby patch of land then being used as a market garden. Cement production probably did not begin again until 1840, for there is no published evidence of his firm until the 1841 Wakefield directory. The entry reads: “Joseph Aspdin. Ornamental Chimney Pipe & Roman cement Manufacturer, Kirkgate, Wakefield.” There is no longer any mention of Portland cement.
In August of 1841, something strange transpired. On August 3, Aspdin drew up a deed transferring a 50 percent share of the business to his oldest son, James, and not William, who had been working at his side for some fifteen years or more. What makes this strange is that James was not in the construction trades. He had decided not to follow in his father's footsteps and had instead studied accounting and become a bookkeeper. Several days later, on August 6, Joseph Aspdin published the following notice, dated a few days earlier, in the Wakefield Journal & West Riding Herald:
TO BUILDERS AND OTHERS
I, Joseph Aspdin of Wakefield, cement maker, take this opportunity of returning my best thanks to my friends and the public, for the numerous favors I have received at their hands for many years past; and beg to inform them that I have just taken my son, James Aspdin into Partnership with me, and that we shall hereafter carry on business under the firm of “JOSEPH ASPDIN & SON.” I think it right at the same time to give notice that my late agent, William Aspdin is not now in my employment, and that he is not authorized to receive any money, nor contract any debts on my behalf or on behalf of the new firm.
Cement Works, Wakefield Joseph Aspdin
2nd August, 184142
We can only speculate why this rupture occurred, though William's later life seemed to suggest a host of reasons, as we shall see. All we know for sure is that William Aspdin had already left his father's firm the previous month (July) and moved to London. He briefly returned the following year to marry Jane Leadman, the daughter of a butcher in Barnsley, a village several miles south of Wakefield. (The marriage certificate shows that no member of the Aspdin family witnessed the nuptials.) William Aspdin then returned with his wife to London, where he would seek his fortune.
William Aspdin's schooling prior to his apprenticeship seemed to have been a bit better than his father's, since he was loquacious and enjoyed writing, and he employed both skills for sales bombast or for relating quite colorful, and thoroughly fictitious, tales. Like all good con men, William could be rather convincing, for he always had the ability to attract investors. He might have gone far in the cement industry and made a large fortune; that he did not do so can be attributed to a character defect: William was an incorrigible liar and swindler.
William Aspdin's departure to the “Big City” was hardly an unusual move for an ambitious person in Britain. London was, and remains, the cultural, political, trade, and communications hub of the United Kingdom. Still, setting off for London and taking up residence there was not something most people could afford to do. William must have saved his money or, more likely, stealthily embezzled funds from his father's firm to finance the move. This would explain the sudden falling out with his family and the disinheritance. Nevertheless, something must have given William the confidence to cut all his familial and material ties to Wakefield and strike out on his own. He had apparently discovered a process that radically improved cement, no doubt stumbling across it after a batch of slurry-mixed cement was overcooked. He then decided to experiment with the vitrified stone by pulverizing it. William evidently kept the secret of the clinkering process to himself, for there is no evidence that his father made clinkered cement after his son's departure to London, let alone anytime before the family fissured.
His first documented appearance in London was recorded in the 1842 directory “William Aspdin. Cement Manufactory. Church Passage, Rotherhithe.” William was not there long, for the 1843 directory shows that he had moved to “Upper Ordnance Wharf & 342 Upper Rotherhithe St.” He was not far from the Thames Tunnel and might have attended the opening ceremonies that year with his wife. Certainly, the tunnel captured his imagination, for he would later use it in one of his most outlandish fabrications. For the present, he was making cement and seeking backers. Although Roman cement overwhelmingly dominated the market, the slurry-mixing method had become more common. William was probably on the lookout for the clinker—overcooked rejects to everyone else—that were so valuable to his process. Who knows what excuse he used for taking these remnants off the hands of the other cement manufacturers, but they were probably happy to get rid of them. It was really ingenious: William did not even have to build a kiln. He only had to hammer the clinker into a powder; certainly not an easy task, but it was the only work he had to perform aside from packaging it. No limestone to purchase, no kilning, no employees. His only overhead were the casks and, of course, his residence/office at the Ordnance Wharf.
It was not long before William Aspdin found partners: John Milthorpe Maude and his son Edmund. John Maude had also come from Leeds as a young man to make his fortune in London. He was a shipping broker who had enjoyed considerable success and was now looking to invest in something promising that he could eventually turn over to his son to manage (he was then sixty-five). Neither he nor his son knew very much about cement. Still, he probably had William's cement tested to confirm the latter's claims for it. The company was formed in the late summer or early autumn of 1843 under the name J. M. Maude, Son & Co. The sole purpose of the firm was to manufacture and sell Portland cement. William ran much of the operation and kept aspects of his manufacturing process cloaked in secrecy.
It is clear that William Aspdin had learned from his father's experience that introducing a new product from a new company was a difficult undertaking. Instead, he presented the cement to his partners as a product long established in the Leeds area and manufactured according to a secret process known only to him and his father. (In truth, he was the only Aspdin with a trade secret.) He probably acknowledged the falling-out with his father, but he no doubt gave a very different and self-serving reason for it. Shortly after the company was formed, a circular was sent out. It is an excellent example of William's chicanery in action. It reads:
The manufacturer of this cement has for many years been carried on by Mr. Aspdin at Wakefield in which neighbourhood and throughout the northern counties of England it has been successfully and extensively used; owing to the heavy charges attending its conveyance to the London market its consumption there has necessarily been limited and although its superiority over other cements has never been contested by those who have been induced to give it a trial, the high price at which alone it could be supplied has hitherto proved a serious impediment to its more general introduction into the metropolis. Messrs J. M. Maude, Son & Co. have now the satisfaction of announcing to the public that they have made arrangements with the son of the patentee for the purpose of carrying on the manufacture of this valuable cement at their extensive premises at Rotherhithe, and whilst they will be enable to supply it at a considerably reduced price, they have also the satisfaction of stating that in consequence of improvements introduced in the manufacture, it will be found for the following reasons infinitely superior to any cement that has hitherto been offered to the public:—
(1) Its colour so closely resembles that of the stone from which it derived its name as scarcely to be distinguishable from it.
(2) It requires neither painting nor colouring, is not subject to atmospheric influences, and will not like other cements, vegetate, oxydate, or turn green but will retain its original colour of Portland stone in all seasons and climates.
(3) It is stronger in its cementative qualities, harder, more desirable, and will take more sand than any other cement now used.
It was very clever to present the cement as long established in Yorkshire and “throughout the northern counties,” and to say that it was only the high cost of transport that prevented it from gaining a foothold in London. In those days, one could not simply pick up a phone and make a call to ask, “Is this stuff really legit?” Leeds was far, far away, and only with the introduction of the locomotive and the interconnection of long rail lines would it become less than a four-day journey from London, the approximate time it now takes a car traveling from New York to San Francisco.
Skipping over the circular's colorful—if misleading—introduction, one cannot find fault with any of Aspdin's claims. All the qualities ascribed to Portland cement were true in every respect. It was by a wide margin the finest concrete cement in the world. Still, it would hardly be the first or last time that a major discovery was made by a duplicitous scoundrel.
At roughly the same time they released this circular, Maude, Son & Co. engaged the highly respected London building firm Grissell & Peto to perform independent tests on Portland cement and several of its prominent rivals. The tests showed that Portland cement was almost twice as strong as the best Roman cements. Records for the firm are scanty for the next couple of years, but we do know that Maude, Son & Co. purchased Parker & Wyatt's old cement works in Northfleet in 1846, so sales must have been good. That same year, John Maude retired and a new partnership formed that included Edmund, Maude's other son, George, a certain William Henry Jones, and, of course, William Aspdin. Oddly, less than a year later, the firm went into bankruptcy.43 The reasons are not clear, but later events might provide a clue.
William quickly found newpartners: William Robins and his son-in-law, George Goodwin. Aspdin was able to retain—or he and his new partners were able to obtain—the cement plant at Northfleet. As before, the new partners had no experience in the cement industry, and they left management of the company in Aspdin's hands. It was at this time that William published an advertisement in several issues of the trade periodical the Builder that was as widely believed as it was unquestionably false. In it, he claims that his father's patented cement was used in 1828 to stop the breach that caused the first flooding of the Thames Tunnel while it was under construction:
It was not until Portland [cement] had been manufactured seven or eight years that its value became apparent and its superiority over all other cements manifest. Then it particularly arrested the notice of Sir [Marc] Isambard Brunel, the eminent engineer and constructor of the Thames Tunnel who tested it with “Roman cement” until he was thoroughly convinced of the great superiority of the Portland, by finding it three times stronger than any other cement then known to the public. Although at that time it cost 20s to 22s per cask, besides the carriage to London, yet Sir [Marc] Isambard Brunel determined (notwithstanding his ability to procure “Roman” at 12/-per cask, delivered on the spot) to adopt it chiefly for his purposes, as its merits required no other recommendation than an impartial trial. When the Thames broke through the Tunnel in 1828, and filled it with water, a large quantity of this Cement was thrown into the river which effectively stopped up the cavity and enabled the contractors to pump out the water; and soon afterwards the work resumed its wonted appearance subsequently obstructed for want of funds.44
This fabrication is so breathtaking in its scope that it would have embarrassed that master of prevaricators, Baron Munchausen. (Most of William's inventions involving famous individuals—he later claimed to have personally convinced Sir Robert Peel not to push for a tax on cement—were published after the individuals in question were dead.) According to both Isambard Brunel's and Richard Beamish's journals, clay was used to stop the flooding, not cement. The only time during the construction of the Thames Tunnel that cement was not used as mortar was for the steening built after the first flooding, and that undoubtedly came from Francis & White, whose firm produced the cement that Marc Brunel always insisted be used for the project. Also incredible is the claim that his father's Portland cement was “three times stronger” than Francis & White's product. This was quited far-fetched, for William's own product, which was quite good, could be claimed to be only twice as strong—a modern engineer estimates 1.8 times45—but beyond that point we find ourselves in the fairyland realm of sales blarney.
Also untrue is William's assertion that this took place “seven or eight years” after his father began producing Portland cement. This would mean that Joseph Aspdin began producing quantities of Portland cement around 1821, at a time when he was still a poor experimentalist covertly stealing limestone from the Yorkshire roads. Yet this fantastic boast was quoted without comment by a historian in the late nineteenth century and later regurgitated as fact in dozens of books, pamphlets, and, of course, Internet sites. Repeat a falsehood often enough, and it assumes the appearance—though not the substance—of truth.
Sales were brisk for William and his third group of partners. The firm also won a prize for their cement at the famous 1851 Great Exhibition in London. The future looked bright, but no company with William Aspdin on its board of directors could ever enjoy prosperity for long. Shortly after the firm's triumph at the Great Exhibition, William obtained £300 from the firm to purchase a steam engine for the cement works. It was later discovered that the engine had cost only £80 and the receipt for it had been forged. This prompted the directors to launch an investigation into William's other dealings at the company. They discovered that money allocated for rent payments found their way into Aspdin's pocket instead, as did wages paid to fictitious employees. As the investigation probed deeper, things got worse. It seemed that there was hardly any major transaction that was not, in whole or part, confiscated by William. When his partners confronted William with the evidence they had gathered, William cursed them roundly and left the premises. The partnership was legally dissolved on November 7, 1851.
William Aspdin quickly found a new partner, Augustus William Ord, a well-to-do retired army officer. Ord possessed the three qualifications Aspdin deemed necessary for a business partner: money, ignorance of the cement industry, and enough faith in William to allow him full reign in running the operation. The new company, Aspdin, Ord & Co., was formed in 1852 and was producing cement by the end of that year.
Despite William's many outlandish frauds and deceits, most people in the cement industry recognized that he indeed made a superior product. For several years, they could only offer lower prices but never compete with him at the quality level. Now, one of them could: a man working for one of William's competitors, John Bazley White—of Francis & White fame—had rediscovered the secret of clinkering.
Francis & White had amicably dissolved their partnership in 1836, the former forming a family company called Charles Francis & Sons, and the latter doing the same with his new firm, J. B. White & Sons. Isaac Johnson, who had worked since his teens in the earlier partnership, stayed with John Bazley White and soon rose to become the manager of his cement works. White recognized the superiority of Aspdin's Portland cement and offered to sublicense its manufacturing on generous terms. Aspdin refused for obvious reasons: the secret process for making Portland cement was the only thing of value he possessed. After Aspdin's refusal, Isaac Johnson stepped forward and told White that he could probably discover Aspdin's secret.
Isaac Charles Johnson lived to a very old age—he died exactly two months shy of his one-hundred-and-first birthday in 1911. He personally witnessed the growth of the cement industry from a small cottage industry to an international manufacturing behemoth. When Johnson was born, even the use of hydraulic mortar was rare; by the time he died, concrete was being used to build everything from streets to skyscrapers. His personal recollections are valuable but sometimes suspect. Johnson is a perfect example of “the last man standing at a gunfight”—the sole survivor who tells everyone else what happened. His most engaging story is about his espionage efforts to discover William Aspdin's secret manufacturing process. Johnson writes that Aspdin had built a twenty-foot-high wall around the factory, and, as a further precaution, the only entrance was through the offices, so that all those coming in could be screened. Johnson tried to find out from his competitor's employees what was involved in the process. Perhaps he bought them beers at the local tavern or slipped them some money. Johnson does not enlighten us, so that aspect remains a mystery.
Yet William Aspdin was no fool. He used various stratagems to distract attention from the clinkering process and to make it appear as if something else was responsible for the quality of his product. He had a large tray of various chemical powders—apparently labeled for all to see—from which he would take small handfuls to toss into the mix at various stages.46 Although he does not say so, Johnson probably tested these—one was copper sulfate—but he could not obtain any good results. Johnson then acquired a sample of Aspdin's cement, perhaps covertly provided by William through one of his employees. Johnson had it analyzed by a chemist, who found that 50 percent of it consisted of calcium phosphate (then called “phosphate of lime”). Johnson felt that he had now discovered Aspdin's secret, for calcium phosphate is the most common chemical component of bones.47 Johnson went to the local butcher shops and bought as many pig and cattle bones as he could, and then began his experiments to replicate Aspdin's secret formula. He spent considerable time testing different proportions of bone dust before realizing that he had been fooled once again. Johnson then tried slurry mixing a formula of two parts ground chalk (a limestone rich in calcium carbonate) to one of clay. This attempt also looked like it would be unsuccessful, since he still could not produce a cement as good as Aspdin's. One day he overcooked the paste, producing hard, “useless” clinker instead. He was about to throw it away when curiosity prompted him to pulverize the clinker and try using the resulting powder as cement. It worked. Until the day he died, Johnson claimed that it was he who had discovered true Portland cement. In fact, it was the same accidental breakthrough that William Aspdin had stumbled upon years earlier.48 Johnson also claimed that “the Portland cement of Aspdin was no more like the cement that is made today as chalk is like cheese!”49 This is nonsense, for Aspdin's cement was held in high regard, and the independent tests conducted by Grissell & Peto certainly confirmed its superiority. While improvements would be made over the coming years to various brands of Portland cement, Johnson's early formula for White's product was probably no more “cheese” than Aspdin's.
Whatever the case may be, the upshot of all this was that William Aspdin now had serious competition from J. B. White & Sons, and it would not be long before other firms also discovered clinkering. The process was no longer a secret held by one man.
As is so often the case when an established brand finds generic versions of its product being offered at the same or lower prices, Aspdin placed advertisements warning the public to be suspicious of such cements and hinted at skullduggery by asserting that his competitors employed manufacturing methods “bought or borrowed.” He also published “tests results” comparing his Portland cement to others. Unlike before, when the tests were conducted by a respected third party, Aspdin oversaw the testing—that is, if we assume any testing was actually conducted. Of course, the results were impossibly skewed in his favor. Aspdin must have realized that the end was near for his Portland cement, as it was no longer the only one bearing that name or offering such quality. He scrambled to find another cement-manufacturing process that would again give his product an edge. In December 1851, he was granted a patent for “the manufacture of Portland and other cements from alkaline wastes.”50 In other words, William was claiming he had found a way to reprocess the waste products from soap manufacturing to create cement. By 1854, he was producing such cement in the Newcastle area to supplement his Portland product.
We cannot gauge the success of this new cement, as the same irrepressible and self-destructive duplicity in William's character broke to the surface again. Aspdin refused to pay rent for his manufacturing premises or make payments for his leased equipment, claiming them to be “unsatisfactory.” The more likely reason for his refusal is that he absconded with the money set aside for these purposes. In February 1855, William Aspdin was arrested for unpaid debts. Although he was able to borrow enough money to obtain his release, William would be involved in one lawsuit after another for the next couple of years. Since he had burned too many people in Britain to ever again do business there, William decided to leave his homeland.
TAWDRY LAST YEARS
The third and final act of William Aspdin's life finds him in Hamburg. Thanks to the meticulous record keeping of the Germans, it is easy to track Aspdin's actions there. A residency form filed with the local authorities shows that he arrived alone on May 22, 1857. He wisely stated his profession as “Buyer” (Kaufmann—all governments back then preferred their foreign visitors to be buyers rather than sellers).
Hamburg and London had been major trading partners since the days of the Hanseatic League, and William made sure that the advertisements he placed in the British construction periodicals were translated and printed in German trade journals as well. William Aspdin's various companies had sold much Portland cement to dealers in the major cities of northern Germany, and his name and brand were well known there.
The political situation in the area around Hamburg was complicated at the time. Hamburg was a self-governing “free city” (Freistadt). Across the Elbe River to the south was Prussia, and to the west, north, and east was Holstein, a German-speaking region of Denmark that nevertheless belonged to the German Customs Union (Zollverein). William's activities would take him to three distinct regions in this one, rather small area—a particular advantage for someone wishing to flee debt collectors or contractual lawsuits. It is as if he had planned an exit strategy years in advance.
We do not know how fluent William's German was, but even at a basic conversational level it would have somewhat curtailed his natural persuasiveness. Perhaps it was for this reason that Aspdin sought out those of his countrymen who had already established themselves in the area. He found an expat named Robert Fawcus, who had come to Hamburg from Hartlepool, England, a few years earlier. Fawcus, along with Alfred Buschbaum, had purchased Klueudgen & Co., a small firm they quickly transformed into a successful coal-importing business. Fawcus and Buschbaum had contracted Aspdin to build their company a Portland cement plant, and it was the fee from this arrangement that financed Aspdin's move to Hamburg.
Either Aspdin had moved fast, or he was already in correspondence with Fawcus before coming to Hamburg. The site for the cement plant, located at Bill Horner Kanalstrasse 10, was purchased exactly one week after William's arrival (May 30, 1857), and the city's planning commission granted their construction application less than three weeks later. The completed plant was inspected on October 4 and was allowed to begin operations. By this time, William had brought his wife and six children over from England and installed them in his new residence in Bille Waerder (now Billwerder), an island on the Elbe River in southwest Hamburg, close to the new factory.
In the rush to build the cement plant, either Aspdin or his partners had clearly not done their homework. Instead of locating the factory near limestone or clay deposits, he decided to import both from England (were kickbacks involved?), even though good sources for these minerals could be found in nearby Prussia and Holstein. Also, his plant was upstream on the Elbe, south of Hamburg's main shipping harbor. According to the regulations established by that city and the Zollverein, this required his company to declare the imported goods twice: the first time, when they arrived at the plant; the second time, when the manufactured cement was “exported” back to Hamburg. The company eventually filed for and was granted a remission from the double duties, but by then they had already produced 89,000 pounds of Portland cement for which nonrefundable import duties had been paid. Five years would pass before the firm would see a profit, but by that time Aspdin was long gone. He had agreed to build the plant and oversee its initial production runs, but nothing more.
In April 1860, a prominent acquaintance of Aspdin's, Adolph Tesdorpf, a member of the Hamburg senate, arranged a meeting between the Englishman and Carl Ferdinand Heyn, a businessman in Lüneburg, a town 45 km (30 miles) southeast of Hamburg in Prussia. Heyn and his brother owned a successful sugar refinery there, as well as nearby land that contained a substantial outcrop of high-quality chalk, the perfect stone for cement production. An agreement was soon reached that called for Aspdin to build a cement plant in Lüneburg for the Heyn brothers. He would also serve as the plant's manager. We do not know if his role as the factory superintendent was to be a permanent position, but Aspdin, then forty-five years old, must have thought about ending his peripatetic existence and settling down.
The Gebrüder Heyn Portland cement plant was up and operating by early 1861. Initially, things seemed to go well, and the factory produced eighteen thousand barrels of quality cement in its first year. However, as was always the case with William Aspdin, the same dark, self-destructive impulses emerged. Despite his success—or to spite his success—Aspdin began drinking heavily and, as a result, quality control at the factory slipped dramatically. Barrels of cement began bursting in the firm's warehouse, and the company had to dispose of their entire stock by dumping it into a pit. Either Aspdin was buying inferior clay, or the problems were due to a secret invention Aspdin developed to test the readiness of the kilned cement. According to coworker Carl Heintzel, no one but Aspdin was allowed to inspect the device. Now that most people in the industry knew the process of making Portland cement, Aspdin apparently felt that he had to have some kind of confidential and proprietary process to call his own and use as leverage. Instead, it caused the Heyn brothers to doubt his competency. Carl Heyn later wrote that, despite his manager's boasting about having been in the business since childhood, “he really doesn't know what he's doing.”51 After eighteen months at the Lüneburg facility, Aspdin either resigned or was fired.
Aspdin moved with his family from Lüneburg to Altona, now a suburb of Hamburg but then a town in Holstein. One report has it that he changed his son's name from “William Aspdin” to “William Altona Aspdin.” He may have written down such a name in a residency form to curry local favor, but Danish and German officials were (are) hesitant to legally alter birth names, so the change was probably unofficial.
While in Altona, Aspdin looked around for other business opportunities. He evidently thought that Holstein was a good place to scout out prospects, since his reputation in Hamburg and Prussia was no longer held in high regard.
William soon found another potential partner, Edward Fewer, an Englishman of Irish extraction. Fewer insisted on contractual protections and an equal say in the running of the business. That William agreed to these terms indicates how desperate he must have been at the time. In early 1862, a contract was drawn up and signed by the two men in Altona. The cement company Edward Fewer & Co. began operations in 1862 at a plant in Lägerdorf next to a virtually inexhaustible outcrop of high-quality Holstein chalk.
Of course, any company with which William Aspdin was involved would experience problems, but this time, the outcome would be very different. After just six months, Aspdin was kicked out of the partnership and given a small compensation check for his trouble. William immediately moved to the small town of Itzehoe, near Lägerdorf, where he published a notice in the local newspaper, the Itzehoer Nachtrichten. This is an English translation of the German text:
After the dissolution of the business relationship in Lägerdorf between Mr. Edward Fewer and myself, I can no longer bear any responsibility for the quality and worthiness of the cement that will henceforth be produced by Edward Fewer. Nor in the smallest degree may he associate my name with his brand. Itzehoe, July 9, 1863.52
It is almost comically ironic that “henceforth” (fortan) Edward Fewer's cement business would thrive.53
Aspdin, already a heavy drinker, drank more. One spring day in 1864, while walking down a street in Itzehoe—or perhaps stumbling along in a drunken stupor—he fell and most likely struck his head on a paving stone. He died soon thereafter, on April 11, 1864. He was forty-eight years old. William Aspdin lies buried in the town's Protestant cemetery.
Had he been an honest individual, Aspdin might have used his superior product to become the dominant player in the cement industry, enriching himself, his partners, and their shareholders. Instead, his serial swindling left nothing in its wake but ruined fortunes, estranged family members, and no one whom he might rightly call “friend” (there is no evidence that he ever owned a dog). One cannot but feel acute compassion for his wife and children, who disappeared from the public records in Germany and presumably moved back to England.
Upon his retirement in 1889, Edward Fewer sold his large and prosperous cement plant to the Alsen'sche Portland Cementfabrik. This would later become the international cement company Alsen, which is now part of the even larger Swiss firm Holcim, one of the largest concrete cement manufacturers in the world. Its success serves as an object lesson for “what might have been.” Had a virtuous version of William Aspdin existed in a parallel universe, he would have achieved more. And had this alternative Aspdin lived as long as Isaac Johnson, and then suffered the same mishap, he might have been killed by his own product.
So, did William Aspdin discover clinkering and, thus, true Portland cement? The research compiled by the esteemed British engineering historian Major A. C. Francis seems to suggest that credit should go—however grudgingly—to Joseph Aspdin's wayward son. I would tend to agree, but a curious discovery made several years ago presents us with a puzzle. In April 2008, archaeologists working at the dockyards in Bristol, England, uncovered the concrete floor of a factory building designed by Isambard Kingdom Brunel to manufacture the engines used for his ship, the SS Great Britain, the world's first propeller-driven, oceangoing vessel. After the Thames Tunnel was bricked up in 1828, Sir Marc Brunel's son shifted much of his attention to solving mechanical engineering challenges in the growing rail and shipping industries. (His contributions in these fields were substantial and later earned him a second-place position—Winston Churchill was first—in the BBC's program 100 Greatest Britons, which polled the UK public to determine the greatest people in British history.)54 The massive concrete floor using heavy aggregate, measures 20 m wide by 50 m long (ca. 66 ft by 164 ft) and 400 millimeters thick (ca. 1.3 ft). The metric measurements appear like something Brunel fil would use—he studied engineering in France and saw the utility and common sense of the new system. However, the concrete seems a product of another era, for, according to Professor Geoff Allen of the Interface Analysis Centre at the University of Bristol, Portland cement was used in its construction. Where did it come from? It certainly did not originate from William Aspdin or his son, since both were then incapable of producing and/or delivering it, especially in such quantities. If William Aspdin had been involved, he certainly would have told the world about it, as he had about so many other things he did and did not do. The quality of Roman cement varied greatly, and some was quite good. Chemical analysis of early Portland cement—like the kind made by William Aspdin and Isaac Johnson—would show the presence of lime, aluminosilicates, and so on, but so would Roman cement made with limestone adulterated with the right amount of clay. Whatever the case may be, the old factory floor at the Great Western Dockyard in Bristol presents us with a mystery requiring more investigation.
At the same time John Smeaton was investigating the hydraulic properties of concrete mortars, some unknown Briton had already rediscovered Roman caementis or, rather, lime concrete. It was a simple mixture of gravel combined with lime that a Neolithic builder or Cato would have immediately recognized. Called “grouted gravel,” it was being used as a foundation material in Britain by the end of the eighteenth century. Although Portland cement concrete would eventually replace the decidedly non-hydraulic grouted gravel, use of the latter for foundation work persisted until the dawn of the twentieth century.
If one were to accept that Joseph Aspdin's 1824 patent for Portland cement describes the process of slurry mixing, he would still be far from the first person in Britain to have used this method. Englishman James Frost was certainly employing the process around the same time Joseph Aspdin filed his patent, and it's possible that he was using such methods earlier, though they are not described in a patent. James Frost began experimenting with hydraulic cements as early as 1810, but he was not satisfied with the results. He traveled to France in 1821 to study under Louis Vicat, the French engineer who was the first person since Smeaton to conduct tests of various limestones to gauge their hydraulic properties. Vicat recognized that clay played an active role in the special characteristics exhibited by natural cements, and he conducted a series of tests to determine the ideal amount of clay to limestone for producing the best results. France has an abundance of clay limestone deposits from which good Roman cement can be produced. The deposits of such limestone in Britain—almost all of it near the coasts of England and Wales—were limited and close to exhaustion by the middle of the nineteenth century. Indeed, it was common in the 1850s to see hundreds of boats employed at dredging clay limestone up from the seafloor just off south England's shores, the land portions of the same outcrops having already been removed to make Roman cement. This scarcity drove up the price of Roman cement. Since limestone rich in calcium carbonate—including chalk—and clays with high aluminosilicate content are quite common on the island, clinkered Portland cement probably saved the British cement industry from disaster. This also explains why Roman cement remained popular in France for a longer time than it did in Britain. It was not only cheaper to manufacture, but its source materials were—are—locally abundant. Quality production of Roman cement is still carried out in France by Vicat S.A., founded in 1853 by Louis Vicat's son, Joseph.
Louis Vicat's experiments, more extensive and detailed than Smeaton's, would have tremendous influence on the French cement industry, which he, in part, fathered. Vicat also discovered that the proper admixture of clay to limestone was between 15 to 20 percent, while the English often employed 30 percent or more in their Roman, and some early, Portland cements. He also began early experiments with artificial cements, by which the amounts of lime and clay are controlled; a method employed by Frost, Dobbs, and Joseph Aspdin. Vicat's architectural masterpiece was the Souillac Bridge in southeastern France, the world's first concrete bridge. Vicat had more faith in the strength of concrete than most of his British contemporaries. Vicat's work inspired many of his countrymen to explore new formulas and applications for the material.
Under Vicat's mentoring, Frost realized all the mistakes he had been making in his earlier experiments and returned to England the following year to set up a cement plant. Strangely, he filed a patent in 1822 that makes even less sense than Joseph Aspdin's. In it, he describes a cement that can be made “without alumino (sic),” something that is impossible, since alumina is a critical ingredient.55 One's first reaction to this patent is to dismiss Frost as someone who was hopelessly behind in his basic chemistry. However, if one takes into account his knowledge gained in France, and the report by a later eyewitness of his manufacturing process, it becomes clear that the patent was simply a device to throw off his competitors, many of whom did have a limited understanding of chemistry. Frost knew exactly how to make good cement, but he was also aware that industrial rivals would subject an Englishman who had studied under the renowned Louis Vicat to extra scrutiny. In tribute to his mentor in France, Frost would name his product “British cement.” (Nationalism and marketing considerations usually trump gratitude.)
In 1828, Charles William Pasley visited Frost's cement factory, by which time it had been in operation several years. Pasley was a highly respected military engineer who was investigating the hydraulic qualities of the various cements then being produced by firms throughout Britain (his notes make no mention of Joseph Aspdin's product). For some reason—perhaps the high regard he held for Pasley—Frost opened up to the engineer and showed him his process for making cement. Pasley's notes show that Frost was practicing slurry mixing, though there is no mention of kilning the paste until vitrification to make clinker. Pasley describes Frost grinding the chalk into a powder and mixing it with water and clay and “by opening a small sluice, [the mixture] was allowed to flow into a…reservoir where it usually remained some months and acquired the consistency of a stiff paste. In this state the material was cut out of the back in lumps and laid on open shelves to dry. When dried, the lumps were broken into smaller pieces and burnt in a kiln of the common inverted cone-like form and in the same manner as lime with alternate layers of fuel and cement.”56
Pasley's description is the earliest of slurry mixing observed in practice. James Frost would later introduce another product that he called, appropriately enough, “British marble,” which was created by crushing chalk and flints to make cement that was quite white when it dried. However, Frost was not happy with the slim profits he was realizing in his cement business. He sold his plant to Francis & White and immigrated to the United States, where he enjoyed a successful career as a civil engineer.
Edgar Dobbs is another figure who evidently used mixing. Whether it was the wet or dry process, we do not know for certain. However, the patent he filed in 1811, while more coherent in its description than many other cement patents of the day, also includes a few red herrings to throw off competitors. He specifies mixing the lime with one or more of the following ingredients, most quite fishy: clay, shale, road dirt (?), mud (?), sandstone, earths (?), and so on. The only component that makes any sense is clay and shale (if the latter was ground). The components were then mixed and kilned. Dobbs seems to have been in business for only a few years, for his company disappeared from the local directory by 1817.57
Another person mentioned in the chronicles and timelines of concrete's progress is William Jessop, whose West India Docks in London were reportedly built of hydraulic cement. However, Jessop used standard lime mortar to build the docks. Apparently, some historian simply assumed that he had used the then-available hydraulic mixes, either Roman cement or trass. In fact, Jessop ordered six thousand tons of Dorking limestone to make his non-hydraulic mortar for the brickwork at the West India Dock.58
The key milestones in the first half of the nineteenth century were the discovery of the properties of natural cement, followed by wet (slurry) mixing, and then clinkering. The other advances are tied to the recognition that hydraulic concrete cement could be used in more ways than simply serving as a waterproof mortar.
NO LONGER JUST A MORTAR
By the early nineteenth century, clay and plaster of paris (the latter made from gypsum) had long been used with molds to cast decorative fixtures or busts of famous individuals. Unfortunately, neither material holds up well to the elements, especially plaster of paris, so such products were restricted to indoor displays. It was not long before people began experimenting with a mixture of cement and sand to create concrete castings that could hold up well outdoors. The first person to do this was James Pulham, a talented artist who worked for cement dealer William Lockwood. (Lockwood would later produce his own cement under the brand name “Portland cement” several years before Joseph Aspdin filed his patent.59) By 1802, Pulham was casting concrete vases, coats-of-arms, pilasters, friezes, architraves, cornices, and sculptures.60 A few years later, Lockwood used Pulham's gifts to construct a house resembling a Gothic castle that incorporated large portions of cast concrete.61 Pulham's talent contributed immeasurably to Lockwood's success in the cement business. More than anyone else at the time, they demonstrated that concrete could do more than just bind masonry blocks. Sadly, both James Pulham and William Lockwood are rarely mentioned in modern histories chronicling the material's progress, although their influence on the early nineteenth-century building industry was substantial. Not only had their house demonstrated that concrete could be used as a monolithic building material, but their cast outdoor ornaments were direct precursors of the concrete objects d'art—and kitsch—that now grace millions of gardens around the world.
Although largely ignored by most people during much of the nineteenth century, the idea of using concrete to cast walls and floors to make houses was an appealing challenge for a few brave souls active in the cement industry. Besides Lockwood, William Aspdin attempted to build a mansion using his Portland cement, but only a third of the structure was completed before financial problems with his last English firm forced him to stop construction. Perhaps a dozen concrete houses were built in England in the 1850s, and a few still remain.
Only with the introduction and wide-scale use of iron, and then steel, reinforcement would monolithic concrete construction finally take wing. By that time, Britain, home to so many innovations associated with the “new” building material, would be left behind by other countries.