Coal and iron took off together. One well-documented foundry, at Qicunzhen, employed three thousand workers to shovel 35,000 tons of ore and 42,000 tons of coal into furnaces each year, harvesting 14,000 tons of pig iron at the other end. By 1050 so much coal was being mined that householders were using it too, and when the government overhauled poor relief in 1098 coal was the only fuel its officials bothered to mention. Twenty new coal markets opened in Kaifeng between 1102 and 1106.
