Casgliadau Arlein

Jympar from Chwarel Gorseddau, Cwmystrallyn. Despite this jympar’s shorter length being worn away / shortened, as one of the only surviving objects from Chwarel Gorseddau it is a unique object.

In the slate quarrying industry, a jympar was a specialized tool used to bore shot holes into the rockface before blasting. It was essential in the days before pneumatic drills and modern explosives (used during the late eighteenth century – mid nineteenth century). A jympar is double ended with a swelling about a third of the way along its length, the shorter length used for starting a hole, and the longer for completing it.

The now disused Gorseddau Slate Quarry was first opened 1807, as a small concern, but its main period of working was between 1854 and 1857 (the ‘golden age’ of the slate industry) when it was developed by the Bavarian mining engineer Henry Tobias Tschudy von Ulster. The quarry was a complete commercial failure. Despite massive capitalisation and investment in milling, water courses and reservoir, workers' housing and railway to Porthmadog, returns were minimal. By 1859, its 200 men were producing less than 1400 tons per annum - seven tons per man year. Output peaked at 2140 tons in 1860. The quarry closed in 1867, possibly with some later sporadic working.

Its development testifies to the fact that everyone that invested in the slate industry expected to make a fortune. Huge sums of money were invested in the quarry, but it failed within a few years of opening because of the poor quality of the slate.

Gorseddau is an outstanding example of a mid-nineteenth century slate quarry landform and tells a story of over-ambitious investment and financial disaster.