According to historical records, an innovation that played a pivotal role in propelling Britain to become the world's leading iron exporter during the Industrial Revolution was actually appropriated from an 18th-century Jamaican foundry. The widely attributed Cort process, credited to Henry Cort, a British financier turned ironmaster, enabled the mass production of wrought iron from scrap iron for the first time. This innovation not only established Britain as an economic powerhouse but also transformed the landscape of the country, leading to the construction of iconic "iron palaces" such as Crystal Palace, Kew Gardens' Temperate House, and the arches at St Pancras train station.

However, a recent analysis of historical documents, including correspondence, shipping records, and newspaper reports, has shed new light on the origins of this innovation. It appears that the Cort process was initially developed by 76 black Jamaican metallurgists working at an ironworks near Morant Bay, Jamaica. Many of these skilled metalworkers were enslaved individuals who were trafficked from thriving iron-working regions in west and central Africa. Dr. Jenny Bulstrode, a history of science and technology lecturer at University College London (UCL) and the author of the study, emphasized the significance of this innovation, stating that it was one of the most crucial advancements that shaped the modern world and catapulted Britain into a major iron producer.

While Henry Cort is commonly credited as the inventor of the Cort process and obtained a patent for it in the 1780s, this new research presents an alternative narrative. It suggests that Cort transported his machinery, along with the fully developed innovation, from the Jamaican foundry that was forcibly shut down. The Jamaican ironworks were owned by a white enslaver named John Reeder, who admitted to being "quite ignorant" of iron manufacturing and acknowledged the expertise of the 76 black metallurgists in running the foundry. These skilled workers were capable of transforming scrap and poor-quality metal into valuable wrought iron, thereby revolutionizing the iron industry.

The innovation introduced by the Jamaican workers involved the use of grooved rollers in the foundry, which mechanized the previously laborious process of removing impurities from low-quality iron. These grooved rollers were similar to those employed in Jamaican sugar mills. Dr. Bulstrode described this process as a kind of "mechanical alchemy," whereby worthless materials were transformed into highly valuable wrought iron.

By 1781, the Jamaican ironworks had become highly profitable, generating an impressive annual profit of £4,000, equivalent to approximately £7.4m in today's currency. In contrast, Henry Cort was facing bankruptcy after taking over an ironworks and incurring substantial expenses to secure a Royal Navy contract for processing scrap iron. However, it was discovered that Cort learned about the Jamaican ironworks through a visiting cousin, a West Indies ship's master who regularly transported seized vessels, cargo, and equipment from Jamaica to England. Shortly after this revelation, the British government declared martial law in Jamaica and ordered the destruction of the ironworks, claiming that it could be used by rebels to manufacture weapons and overthrow colonial rule.

This groundbreaking study, published in the journal History and Technology, challenges the traditional narrative surrounding the Cort process and highlights the crucial contributions of the black Jamaican metallurgists whose ingenuity and expertise paved the way for Britain's iron industry dominance.