An isolated upland area, nine-and-a-half miles east-south-east of Aberystwyth, is the site of one of Wales’ richest mines, with a combined output of over 100,000 tons of lead and zinc ores. The near vertical veins occur in grey or greenish-grey shales, flags and mudstones of Silurian age.
There had been some mining before 1792, when John Probert was developing what became Frongoch, but not much. Probert worked until around 1818 when low lead prices all-but closed the mine. When the market recovered in 1824 Lord Lisburne’s mines, including Frongoch, were leased to the Williams brothers of Scorrier House in Cornwall. Unfortunately for them lead prices fell sharply in the late 1820s and early 1830s, and they gave up the mines in 1834.
Their successors, John Taylor & Sons, had much more luck with prices and finding ore. They worked as the Lisburne Mine Co. which included a number of other mines as well as Frongoch. Their first company report, with understatement not typical for such a document, stated that “a more spirited mode of working has been adopted”. Pumping was done by a 40 foot waterwheel, but a steam engine, for winding and crushing, was bought in 1841. A large new reservoir was built and the old ones improved in order to maintain a supply of water for the wheel. By July 1863, however, the mine was 103 fathoms deep and the bottom levels were stood because of a shortage of water for the pumping wheel.
As was the Cornish custom, the deep shafts were sunk down the line of the vein. This was cheaper, but it made them irregular and inefficient for modernisation.. In 1875, therefore, a deep vertical shaft was begun. Called Vaughan’s New Shaft, it intersected the lode at the 90 fathom level.
Under the Taylors, the mine made £600,000 profit over 44 years, but in 1878 it made a loss. The first since 1842. Nevertheless, they decided to let the mine go and it passed John Kitto. As well as lead ore, he also worked the zinc blende, which the Taylors had practically ignored. Because some stopes were very large, a system was developed for backfilling them with crushed waste, the size of coarse sand, poured through square pipes.
Working costs were still too high, and ore prices were low. Kitto kept Frongoch working until 1897 when he was nearly 70 years old and retired. The mine, which was now 154 fathoms deep, passed to the Society Anonyme Des Mines De Frongoch. The shafts etc were repaired down to the 90 fathom level, and lower levels were allowed to flood. A modern dressing plant was built to deal with the zinc and stopes for that metal begun. Old pillars were worked for lead. Most drilling was still by hand and was, therefore, slow and expensive. Because the company could not afford to install compressed air plant, electric drills were tried, but were found wanting and the mine closed in December 1902. The mill worked dump material until August 1903, and then the mine closed.
- Bick, D. Frongoch Lead & Zinc Mine (British Mining No.30, 1996)