By reinterpreting a mysterious recipe for bronze in a 2300-year-old text, researchers say ancient foundries in China relied on pre-prepared alloys—which points to vast supply chains supporting an even more complex bronze industry than previously suspected.
In 1976, archeologists excavated more than 1.5 tons of bronze from the 3000-year-old tomb of Fu Hao, a Chinese general in the Shang dynasty. The number of artifacts reflected the scale of bronze production in imperial China, which far outstripped anything occurring in Europe at the time.
“China was producing hundreds of tons of bronze a year,” says Mark Pollard, an archaeologist at the University of Oxford and co-author of the new study. “It’s a massive scale and it’s a really important part of the imperial economy.”, a technological encyclopedia with parts that originated some 2500 years ago. It contains instructions on how to make carriages and musical instruments, and even holds rules for building a city.
To get a better sense of what jin and xi might be, Pollard and Ruiliang Liu, an early-China curator at the British Museum, decided to look for clues in previous chemical analyses of ancient bronze coins. The majority of such coins could be made byPollard and Liu propose these two alloys, which could have been prefabricated as ingots and distributed to bronze foundries, are jin and xi.
Jianjun Mei, an archaeo-metallurgist at the University of Cambridge, is skeptical. “There is no convincing analytical evidence to support their claim that jin and xi are not pure copper and tin, but pre-prepared alloys,” he says. He says the presence of lead in some bronzes can be explained using the theory that thewas written by administrative officials and not craftsmen. “These officials might only pay attention to the most important materials–copper and tin.
Yet Mei still welcomes the paper’s attempt to reinterpret the recipes. He says knowing how the ancient bronze artifacts were made helps researchers understand the civilizations that used them. “We have no idea where these objects–the statues or vessels–were made, who made them, and where the material came from,” he says. “The first step is to understand the technology that was used” to make the bronze.