Distillations magazine

Unexpected Stories from Science’s Past

Hard-Headed Man

When William Aspdin stumbled on the secret to modern concrete, it was the first and one of the few fortuitous steps in an unsteady life.


Innovators are often celebrated by later generations for their genius, their fortitude, their strategic thinking, or at least the perspicacity that led them to make the most of a piece of good luck. Occasionally, though, a person who makes a world-changing discovery completely flubs his big chance. Such was the case with the London cement manufacturer William Aspdin, who sacrificed a unique triumph to his own greed, crookedness, and ineptitude and has all but disappeared from history.

Aspdin’s commercial debut was promising enough. In 1843 he came out with a wondrous new version of Portland cement, which stood out from other materials being sold under the same name. When mixed with sand and water and allowed to dry, Aspdin’s product hardened into a concrete that was almost twice as strong as blocks made using standard cements of the time.

Testing found that it took a load of more than five hundredweights—more than 600 pounds—to break a beam of the new concrete, compared with less than three hundredweights for the older product. One competitor later recalled “the flourish of trumpets that was then being made about the new cement.”

The new product appeared at the tail end of the Industrial Revolution, a period of ambitious infrastructure projects, such as the Thames River tunnel in London and the Erie Canal in the United States, both of which made extensive use of cement. But Aspdin discovered a crucial step in manufacturing what came to be considered modern concrete—the ubiquitous material that would be used in future years to build canyon-soaring bridges, colossal dams, millions of miles of sidewalks and roads, and countless sewers, museums, government buildings, and other structures.

Despite the obvious importance of Aspdin’s discovery, it’s difficult to stir up admiration for the man or even to understand how he made his discovery. He had little or no science education; he likely stumbled on his discovery by accident; he deliberately cloaked his work in mystery; and through swindling or incompetence he ruined several business partnerships. He never filed a patent on his cement, using instead an older patent belonging to his father, Joseph. As a result Joseph is often incorrectly credited with his son’s crucial innovation—an ironic outcome given that the elder Aspdin had kicked William out of the family business, apparently after one of William’s many financial missteps.

“I think it right,” Joseph wrote in an 1841 newspaper notice, “to give notice that my late agent, William Aspdin, is not now in my employment, and that he is not authorised to receive any money, nor contract any debts on my behalf or on behalf of the new firm.”

Having banished his son from the family cement works near Leeds, Joseph went on making his same old cement. Like many others, he used a version of an ancient method in which limestone, which is mostly calcium carbonate, is burned to make powdered lime, mixed with clay and water, fired again, and pulverized into cement powder.

William Aspdin, however, had realized the usefulness of “clinker”—hard, overburnt rocks of lime-clay mixture that were considered useless for cement and thrown out. It turns out that higher firing temperatures produce calcium silicates that, when mixed with water, give cured concrete much greater strength. Aspdin ground up the clinker, packed the powder in casks, and founded the modern cement business.

Patenting and marketing a brand-new material would have been far too risky financially, according to Arthur James Francis, a civil engineer and historian who researched Aspdin’s career. Instead, Aspdin moved to distant London, found a financial backer, and started advertising his product as an improved version of his father’s Portland cement.

“In consequence of improvements introduced in the manufacture,” an advertisement said, the product was “infinitely superior to any cement that has hitherto been offered to the public. . . . It is stronger in its cementative qualities, harder, more durable, and will take more sand than any other cement now used.”

Competitors took notice and started sniffing around. Lacking patent protection for his clinkering process, Aspdin went to great lengths to hide it, using misdirection and tight security.

Isaac Charles Johnson, the rival cement maker who noted the “flourish of trumpets” over the new product, recalled that Aspdin’s cement works “was closely built in, with walls some 20 feet high, and with no way into the works, excepting through the office.” Johnson later learned from one of Aspdin’s partners that Aspdin personally supervised the production of his cement.

“The process was so mystified that anyone might get on the wrong scent—for even the workmen knew nothing, considering that the virtue consisted in something Aspdin did with his own hands,” Johnson wrote years later. “Thus he had a kind of tray with several compartments, and in these he had powdered sulphate of copper, powdered limestone, and some other matters. When a layer of washed and dried slurry and the coke had been put into the kiln, he would go in and scatter some handfuls of these powders from time to time as the loading proceeded, so the whole thing was surrounded by mystery.”

Johnson’s recollections should be read with a critical eye, as he would contend for the rest of his life that he was the creator of “true” Portland cement due to improvements he had made in the manufacturing process. But his narrative fits the historical record; he describes conducting months of experiments and his own eventual discovery of the value of clinker. And the firm he worked for did start selling higher-strength clinkered Portland cement by 1845.

The new competition rattled Aspdin. In 1847 his firm went bankrupt, and he had to find new backers. He started fabricating claims about his product and attacked his rivals.

In one preposterous series of ads he claimed his father’s cement had been used by the engineer Isambard Kingdom Brunel to end an 1827 flood during construction of the first Thames River tunnel. “A large quantity of this Cement was thrown into the river which effectually stopped up the cavity,” Aspdin wrote in an advertising pamphlet. This is almost certainly untrue, as Brunel himself said he used clay and gravel, and there is no record of Joseph Aspdin himself ever trumpeting what would have been a remarkable selling point for his cement. Even if true, the material the elder Aspdin was manufacturing in the 1820s was not clinkered Portland cement.

As the cement produced by Johnson’s employer gained prominence, Aspdin sought to remind potential buyers that he had been there first. “They cannot claim any invention of their own in cement,” he complained in another ad. “Their knowledge of manufacturing has been either bought or borrowed and no merit is due to them in the manufacture of the article.”

Aspdin continued manufacturing, but his own actions hampered his ambitions. He started building himself a sprawling mansion encased in Portland cement even as he accumulated hundreds of pounds of debt. Court summonses piled up. A partner alleged that Aspdin embezzled cement and lime revenues, as well as money Aspdin had claimed was needed to pay workmen and buy a steam engine.

When a judge ordered the partnership dissolved, Aspdin found yet another backer and occupied a grand, new cement works in Gateshead, “crowned by a colossal figure of Hercules vainly endeavouring to break upon an anvil a beam of bricks united by the Patent Portland cement of which he is himself made,” a local newspaper reported. Aspdin even finally obtained a patent, not for Portland cement but for a process of extracting lime from soap factories’ alkali wastes. Over the next few years his company released new testing results for its concrete, some of them credible and some later described as “fantastically high” by one researcher.

For a time Aspdin appeared successful again. In 1854 he was elected to Gateshead’s town council as a business-friendly candidate. But he had dodged paying rent on his elaborate new cement works, claiming its machinery was unsatisfactory, and the owner pursued a case against him. Isaac Johnson again served as Aspdin’s nemesis, examining the facility and reporting that its machinery was fine. Aspdin was then arrested for a separate unpaid debt, his company was declared bankrupt, and he was removed from office. He tried selling his partly built mansion but failed and lost the property.

Aspdin’s career was winding down. He formed one more brief partnership in England before decamping to Germany with his family in the late 1850s. He started up another cement works that soon failed, then another that split up over disagreements between the partners. He died in 1864 at the age of 48.

Johnson eventually took over the Gateshead cement works and found great success, becoming the town’s mayor and later a county magistrate, obtaining three patents, and disparaging Aspdin’s cement for decades to come.

William Aspdin’s name largely faded from cement’s official origin story, with his father being credited for his groundbreaking product. He was survived and eclipsed by successors who greatly improved cement manufacturing through systematic scientific study and the introduction of innovations such as the rotary kiln. But despite Aspdin’s deep flaws, his discovery reserves for him an undeniable role in the development of a crucial building block of the world’s infrastructure.

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