The last smelter to work in Cornwall, at Seleggan, which closed in 1931, still adhered to the traditional reverberatory practice to the end, although a small blast-type furnace may have been used at times to remelt slags. There was a great air of secrecy about Seleggan, and those who worked there were enjoined: 'never ask any questions'. A photograph of the works appears in Barton, but it must have been taken early on as it shows multiple, rectangular stacks. A huge system of large-diameter circular pipes leading from every furnace to a big ‘bag house' was in place by the 1930s, as it was found there were considerable losses in the flues in the older furnaces. The cloth bags were cleaned off from time-to-time, yielding much valuable tin as oxides, indeed this was the last example of dust collection first seen in the large 'room' above the ancient hearth blowing furnaces. The reverberatories were 'flat topped', of brick and bound with iron bars. Latterly, the firing was by burners entering the side of the furnace over the hearth, some furnaces using powdered coal, others oil fuel which proved to be the best. The metal was tapped into the usual large hemispherical iron basins and, after purification, cast into rectangular iron moulds, one of which is to be exhibited at the Camborne School of Mines museum at King Edward Mine. A mason in Camborne was employed full-time on rebuilding the furnaces, which sometimes collapsed sending tons of tin metal into the ground beneath the crude collecting pit. Two large circular brick stacks were all that was left of the works by the 1960s, its slag dumps having been reworked by smelters 'up country'.72