Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne 1838 Vol.2.djvu/173

Rh and m, Fig. 3, with the flame and blast principally issuing between the forestone and workstone, as at m, a stratum of ore is spread upon the horizontal surface of the brouse, at l, and the whole suffered to remain exposed to the blast for the space of about five minutes. At the end of that time, one man plunges a poker into the fluid lead, in the hearth bottom below the brouse, and raises the whole up, at different places, so as to loosen and open the brouse, and in doing so, to pull a part of it forwards upon the workstone, allowing the recently added ore to sink down into the body of the hearth. The poker is now exchanged for a shovel, with a head six inches square, with which the brouse is examined upon the workstone, and any lumps that may have been too much fused, broken to pieces; those which are so far agglutinated by the heat, as to be quite hard, and further known by their brightness, being picked out, and thrown aside, to be afterwards smelted in the slag hearth. They are called Grey Slags. A little slaked lime, in powder is then spread upon the brouse, which has been drawn forward upon the workstone, if it exhibit a pasty appearance; and a portion of coal is added to the hearth, if necessary, which the workman knows by experience. In the mean time, his fellow workman, or shoulder-fellow, clears the opening, through which the blast passes into the hearth, with a shovel, and places a peat immediately above it, which he holds in its proper situation, until it is fixed, by the return of all the brouse, from the workstone into the hearth. The fire is made up again into the shape before described, a stratum of fresh ore spread upon the part I, and the operation of stirring, breaking the lumps upon the workstone, and picking out the hard slags repeated, after the expiration of a few minutes, exactly in the same manner. At every stirring a fresh peat is put above the nozzle of the bellows, which divides the blast, and causes it to be distributed all over the hearth; and as it burns away into light ashes, an opening is left for the blast to issue freely into the body of the brouse. The soft and porous nature of dried peat moss, renders it very suitable for this purpose; but, in some instances, where a deficiency of peats has occurred, blocks of wood of the same size have been used with little disadvantage. As the smelting proceeds, the reduced lead,