Vivian’s works, the most important of the establishments of Swansea, are situated in a vale a couple of miles from the town. A maritime canal enables brigs to sail at high tide up to the smelting furnaces, whence a second canal leads to the coal-pits, ascending the hill by a succession of locks. Although in the building of this huge factory not a thought was given to grace or beauty of form, utility being the sole aim in view, still its vast extent leaves on the mind a certain impression of grandeur. The whole smelting process is carried on in reverberatory furnaces.[49] In order to disengage the sulphur and other volatile impurities, the ore is first roasted in at least sixteen of these powerful ovens, each of which holds forty hundredweight, and performs its office in six hours. The smoke of all these furnaces collects in a huge chimney, which, after climbing the hill for about six hundred feet, ends in a mighty column two hundred feet high. The roasted ores are then mixed with a certain proportion of fluor spar, and smelted in twenty smaller reverberatory furnaces. A ton is introduced at a time, and in each oven seven tons can be smelted in twenty-four hours. It would lead me too far were I to enter into more minute details. I will therefore briefly state that the copper is still obliged to pass four times through differently constructed furnaces before it is sufficiently pure to be rolled into sheets or to be granulated, a condition in which it is used for the fabrication of brass, as it then presents more surface to the action of the zinc, and combines with it more readily. To produce this granulation, the metal is poured into a large ladle pierced with holes, and placed above a cistern filled with water, which must be hot or cold according to the form of the grains required. When it is hot, round grains are obtained, analogous to lead shot, and the copper in this state is called _bean shot_. When the melted copper falls into cold water perpetually renewed, the granulations are irregular, thin, and ramified, constituting _feathered_ shot. Footnote 49: A reverberatory furnace is a furnace in which intense heat is produced by a flame which, while passing through a furnace, _reverberates_ from the roof over the substance to be fused, the draught being created by means of a lofty chimney.