A metallurgical process that was crucial to the Industrial Revolution was invented by Black metallurgists, many of whom were enslaved – and not by British entrepreneur Henry Cort, who took the credit.
“This innovation is the basis of suspension bridges, iron ship building, textile mills,” says historian of science at University College London. “This innovation was in fact stolen by Henry Cort.”
Despite his importance to the Industrial Revolution, Cort is a mysterious figure; even his birthdate is unknown. He was a banker who in 1775 took over a Portsmouth foundry owned by one of his debtors, and lost a lot of money. Then, in 1780, he secured a contract with the Royal Navy to supply iron hoops for barrels.
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However, the contract was a bad one. “Basically, they’d screwed him,” says Bulstrode. Cort had agreed to take on large quantities of the Navy’s scrap metal, but there was no profitable way to turn this into high-quality iron on a large scale to make the hoops.
Then, in 1783, Cort patented a process in which bundles of iron were heated in a modified furnace and fed through grooved rollers. The individual processes and elements already existed, but they were combined in the patent in a wholly novel way. While the resulting metal was still fairly impure, it was far stronger and could be used to build huge structures.
Cort’s plan didn’t work out. He had funded the business through a loan from a Navy employee, Adam Jellicoe, who had embezzled Navy funds. When Jellicoe died in 1789, Cort was held liable for his debts, went bankrupt and lost control of the patents. “An extremely valuable process that was patented in Cort’s name is suddenly free to use and you suddenly get it taken up all over Britain,” says Bulstrode.
How Cort devised the process has always been a mystery. “There is absolutely no sign of any experiments, of what work he did to get there,” says Bulstrode.
Jamaican foundry
The answer, Bulstrode says, is theft. She came across an archaeological report of a foundry site in Jamaica that was doing the Cort process before he was supposed to have invented it. After trawling through records, she has assembled a hitherto-unknown sequence of events.
In 1772, an Englishman named John Reeder established a foundry in Jamaica, then a British colony. “Reeder’s Pen” supplied equipment for the sugar trade and was operated by 76 Black metallurgists. Many were taken from Africa by the British and enslaved, although some were Jamaican Maroons, a group who had freed themselves from slavery decades earlier.
According to Reeder’s account, the foundry workers’ “perfect” skills enabled them to convert 3000 tonnes of scrap metal into bar iron, using furnaces and rolling mills. The grooved rollers they used were standard in sugar cane processing but hadn’t previously been used for metalworking.
The foundry was illegal under British colonial law, because previous anti-slavery rebellions had relied on weapons forged illicitly in such foundries. As a result, a decade later it was shut down.
Taken to England
Bulstrode also found a link from the foundry to Cort. In spring 1781, his cousin John Cort arrived in Jamaica. At the time, the biggest news on the island was that a freedom fighter named Three-Finger Jack had been killed – by Kwasi, one of the Maroons working in the foundry. John Cort almost certainly heard the story.
Later that year, John Cort’s ship ran into difficulties and was forced to divert to Portsmouth, where he arrived in November 1781 and found his cousin Henry floundering. There is no record of their conversations, but in spring 1782, Reeder’s foundry was dismantled and loaded onto ships headed for Portsmouth. “And the next thing you get is sugar rollers in Henry Cort’s foundry in Portsmouth,” says Bulstrode.
The story reflects an under-appreciated aspect of the trade in enslaved African people, says Bulstrode: it exploited their expertise and inventiveness as well as their physical labour. The regions of west and west-central Africa targeted by the British slave trade are “some of the most significant iron-working regions in world history”, she says.
“If you are someone enslaved, then your labour, your intellectual inputs, your knowledge, your skills and everything, they are owned by the person that owns you,” says at the University of Oxford, who wasn’t involved in the study.
This was a recurring pattern, says Chirikure. Some of the people enslaved from what is now Angola were chosen for their skills in copper smelting. “They made significant contributions to copper mining in Cuba, copper mining in Brazil and in other places,” he says.
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