The boom times at Minera lead mines started in the 18th century.
Prospectors had learned how to find the underground reserves of lead. However, deep mining had its problems. The lead veins (1) are in limestone. Limestone means underground rivers so flooding in the mines was always a problem. Pumping this water out was costly and a major obstacle to any successful deep mining for lead.
The man with the solution in the late 18th century was John Wilkinson, entrepreneur and the brains behind Bersham Ironworks. Wilkinson's steam engines were the best yet at keeping the mines free of water. Lead mining was once again profitable. Unfortunately, Wilkinson did not tell Boulton & Watt about his pirated copies of their steam engines. They found out and Wilkinson had to pay up.
Those pumping engines were vital. When problems with the pumps and disputes over paying for the engines led to the pumping stopping, the mines once again closed.
In 1845 John Taylor & Sons, mining agents from Flintshire, formed the Minera Mining Company. They had the experience. They knew Minera's lead mines had potential. They consolidated the mining leases, put in a new drainage level from Nant Mill to get water out of the mines and invested in new engines and a new railway line. In 1852 lead ore was, once again, being mined at Minera.
The miners discovered new reserves of lead deeper underground. It was boom time. The Taylors had started off with £30,000 to invest in their mining venture; the profits for 1864 alone were over £60,000.
The good times continued into the 1870s, but there were problems ahead. The price of lead started to fall, while the price of coal to keep the pumping engines running rose. Reserves of lead were starting to run low. Zinc, the other metal mined at Minera, also fell in price. By the late 1890s, mining at Minera no longer made much economic sense.
In 1909 the mining company decided the pumping engines were too expensive to run. The mines started to flood. In 1914 lead mining stopped. The machinery was sold and the last few miners helped the owners salvage the remains of the business. It was the end of an era for Minera.
(1) The lead ore runs in veins underground. Lead veins, unlike coal deposits, are nearly vertical in this area, and run roughly west to east across the landscape.