Slate was extracted from five underground chambers which were below the water table and were pumped using a waterwheel.

[1] Cymerau had several private wagons which it used to haul slate along the Ratgoed Tramway and on down the Corris Railway to Machynlleth.

[4] Cymerau and Ratgoed were worked as a single operation immediately before the First World War.

Cymerau re-opened on a smaller scale after the conflict, owned by the Inigo Jones company of Groeslon.

[7] Slab from the quarry was roughly shaped and planed in the Cymerau Mill, before being shipped out by the Ratgoed Tramway to Aberllefenni, then the Corris Railway to Machynlleth, before being transferred to the main line and shipped to Groeslon for finishing and enamelling.