[Fig. 1015.] is the front elevation of the twin furnaces, built in one body of masonry; [fig. 1016.] is a plan taken at the level of the tuyères, in the line v, l, 6. of [fig. 1017.]; [figs. 1017.] and [1018.] exhibit two vertical sections; the former in the line A, B, the latter in the line C, D, of [fig. 1016.] In these four figures the following objects may be distinguished.
a, b, c, d, a balcony or platform, which leads to the place of charging n; e, f, wooden stairs, by which the charging workmen mount from the ground p, q, of the works, to the platform; g, h, brickwork of the furnaces; i, k, wall of the smelting-works, against which they are supported; l, upper basin of reception, hollowed out of the brasque (or ground charcoal bed) 6; m, arch of the tuyère v, by which each furnace receives the blast of two bellows; n, place of charging, which takes place through the upper orifice n, o, of the basin n, o, v, t, of the furnace; t, a slab of clay, placed in such a way that, during the treatment of the lead, a little metallic zinc may run together in a sloping gutter, seen in [fig. 1001.], formed of slates cemented together with clay.
In [figs. 1015] and [1017.], l, z, is the brickwork of the foundations; m, conduits (called evaporatory), for the exhalation of the moisture; 4, a layer of slags, rammed above; 5, a bed of clay, rammed above the slags; 6, a brasque, composed of one part of clay, and two parts of ground charcoal, which forms the sole of the furnace.
