Gunpowder magazine at Llywernog Mine

Cadw's description

Location

Situated on slope at NW corner of lead-mine site reached by track from main mine buildings past ruin of late C18 mine office.

History

Powder magazine for Llywernog mine, probably mid-C19. Llwyernog mine was discovered in the C18, said to have been worked as opencast by Lewis Morris c1744-56. Two mines were noted by Meyrick in 1810, one worked by Sir Thomas Bonsall (Powell's Mine S of A44), the other by W. Poole ( the present Llywernog). Leased in 1825 to Williams family of Scorrier House, Cornwall, and references to other lessees in 1840 and 1852, before Llywernog United Mining Co.. formed in 1858 (also working the Ponterwyd and Bog Mines), bought out by Clara United Mining Co.. in 1859. Pumping problems were not solved until a 40' (12.2m) water wheel was bought in 1861 from Bodcoll Mine. Worked successfully to c. 1873 but with constant problems with water supply for draining the workings. There were 14 men working in 1867, 24 in 1872. Captain John Davis was mine manager 1867-72, Captain John Evans 1872. John Balcombe was manager of the Llywernog Mining Co.., formed 1868. Steam power was installed in 1870 and the new main building dates from 1869-70. In 1871 the mine reached its greatest depth at 72 fathoms (132m) but problems with finance led to the lease being sold in 1872. In 1874-5 Balcombe bought a 50' (15.25m) wheel to replace the 40' (12.2m) wheel, one of the largest in the region. New leats of some six and a half miles (10.5km) were built to bring water from the upper Rheidol valley but returns ceased about 1875. Sporadic work c1882-91 is recorded. Reopened again 1907-10 by the Scottish Cardigan Mines Ltd but nothing was produced. The giant wheel was scrapped in 1953. The site was restored from 1973 by Peter Lloyd Harvey as a museum.
A 1949 photograph shows the office building, the giant waterwheel in its raised wheel-pit to left, adjoining the rubble stone square base of the rock-crusher house. On the hill behind is the roofless ore-dressing shed. The powder magazine was built away from other buildings for risk of explosion, and is like those at Cornish mine sites, circular with a corbelled stone roof.
The building is in poor condition with steel hawsers binding the exterior stonework.

Exterior

Powder magazine, rubble stone, circular with row of projecting stones under corbelled stone low conical roof of flat stones with circular top stone. The only entry is to the N, full-height, square-headed with timber lintel.

Interior

Circular interior with roof springing from a wall-head of overhanging stones. Corbelling of rings of flat stones.

Reason for designation

Included as a rare surviving lead-mine powder magazine of group value with other listed buildings at this well-preserved mine, a Scheduled Ancient Monument.