Initially, the smelting works concentrated on copper. Coal was brought down to them by waggonways and tramways; copper ore was brought on ships which could sail right up to the works; and the resulting copper was exported out again the same way. Swansea became known as Copperopolis; and the lower Tawe valley became a mass of industry. In the wake of the copper and coal industry followed pottery-making (another industry which requires large amounts of coal, together with clay and flint, which could be shipped in from the West Country); the alum industry (based on pyrites found with coal); and the manufacture of fire-clay, which was used to line furnaces.