Portside

An innovation that propelled Britain to become the world’s leading iron exporter during the Industrial Revolution was appropriated from an 18th-century Jamaican foundry, historical records suggest.

The Cort process, which allowed wrought iron to be mass-produced from scrap iron for the first time, has long been attributed to the British financier turned ironmaster Henry Cort. It helped launch Britain as an economic superpower and transformed the face of the country with “iron palaces”, including Crystal Palace, Kew Gardens’ Temperate House and the arches at St Pancras train station.

Now, an analysis of correspondence, shipping records and contemporary newspaper reports reveals the innovation was first developed by 76 black Jamaican metallurgists at an ironworks near Morant Bay, Jamaica. Many of these metalworkers were enslaved people trafficked from west and central Africa, which had thriving iron-working industries at the time.

Dr Jenny Bulstrode, a lecturer in history of science and technology at University College London (UCL) and author of the paper, said: “This innovation kicks off Britain as a major iron producer and … was one of the most important innovations in the making of the modern world.”

The technique was patented by Cort in the 1780s and he is widely credited as the inventor, with the Times lauding him as “father of the iron trade” after his death. The latest research presents a different narrative, suggesting Cort shipped his machinery – and the fully fledged innovation – to Portsmouth from a Jamaican foundry that was forcibly shut down.

The Jamaican ironworks was owned by a white enslaver, John Reeder, who in correspondence described himself as “quite ignorant” of iron manufacturing, noting that the 76 black metallurgists who ran the foundry were “perfect in every branch of the iron manufactory”, and, through their skill, could turn scrap and poor-quality metal into valuable wrought iron.

Some of these workers are named in records, and include Devonshire, Mingo, Mingo’s son, Friday, Captain Jack, Matt, George, Jemmy, Jackson, Will, Bob, Guy, Kofi and Kwasi.

Their innovation came after the workers introduced the use of grooved rollers into the foundry to mechanise the formerly laborious process of hammering out impurities from low-quality iron. The same kind of grooved rollers were used in Jamaican sugar mills.

“It’s like a mechanical alchemy,” said Bulstrode. “You’re taking essentially rubbish and turning it into something of very high value through this process.”

By 1781, the Jamaican ironworks was turning an impressive profit of £4,000 a year, equivalent to about £7.4m today. Meanwhile, Cort was facing bankruptcy, after taking over a client’s ironworks in 1775 and laying out substantial sums to win a Royal Navy contract to process its scrap iron, before realising he stood to make a huge loss.

The paper, published in the journal History and Technology, traces how Cort learned of the Jamaican ironworks from a visiting cousin, a West Indies ship’s master who regularly transported “prizes” – vessels, cargo and equipment seized through military action – from Jamaica to England. Just months later, the British government placed Jamaica under military law and ordered the ironworks to be destroyed, claiming it could be used by rebels to convert scrap metal into weapons to overthrow colonial rule.

“The story here is Britain closing down, through military force, competition,” said Bulstrode.

The machinery was acquired by Cort and shipped to Portsmouth, where he patented the innovation. Five years later, Cort was discovered to have embezzled vast sums from navy wages and the patents were confiscated and made public, allowing widespread adoption in British ironworks.

Bulstrode hopes to challenge existing narratives of innovation. “If you ask people about the model of an innovator, they think of Elon Musk or some old white guy in a lab coat,” she said. “They don’t think of black people, enslaved, in Jamaica in the 18th century.”

Dr Sheray Warmington, an honorary research associate at UCL, said the work was important for the reparations movement: “It allows for the proper documentation of the true genesis of science and technological advancement and provides a starting point for how to quantify and repair the impact that this loss has had on the developmental opportunities of postcolonial states, and push forward the discourse of technological transfer as a key tenet of the reparations movement.”

[Hannah Devlin is the Guardian's science correspondent, having previously been science editor of the Times. She has a PhD in biomedical imaging from the University of Oxford. Hannah also presents the Science Weekly podcast.]

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