SILVER 



813 



purpose, with three tuyeres, and a cylinder bellows ; /, the large furnace of fusion, also 



with three tuyeres ; g, a furnace with seven tuyeres, now seldom used ; /;, low furnaces, 



like the English slag-hearths 



(Krummbferi), employed for 



working the last mattes; k, 



slag-hearths for reducing the 



litharge ; m, the area of the 



liquation ; , n, cupellation 



furnaces. 



x, y, a floor which separates , _ 



the principal smelting-houses (I ,-T-^V ^J \\ 



into two stories ; the mate- J 

 rials destined for charging 

 the furnaces being deposited 

 in beds upon the upper floor, 

 to which they are carried 

 by means of two inclined planes, terraced in front of the range of buildings. 



Fig. 1805 represents such wooden bellows, consisting of two chests or boxes, fitted 

 into each other ; the upper or moving one being called the fly, the lower or fixed one 

 the seat (gite). In the bottom of the gite there is an orifice furnished with a clack- 

 valve, d, opening inwards when the fly is raised, and shutting when it falls. In order 

 that the air included in the 



capacity of the two chests 1805 



may have no other outlet than 

 the nose-pipe m, the upper 

 portion of the gite is provided 

 at its four sides with small 

 square slips of wood, c, c, c, 

 which are pressed against the 

 sides of the fly by strong 

 springs of iron wire, b, b, b, 

 while they are retained upon 

 the gite by means of small 

 square pieces of wood, a, a, a, a. 

 The latter a, a, are perforated in the centre, and adjusted upon rectangular stems, 

 called buchettes ; they 

 are attached, at their L_I_I s_ 

 lower ends, to the up- 

 right sides of the gite 

 G. p is the driving- 

 shaft of a water-wheel, 

 which, by means of 

 cams or tappets, de- 

 presses the fly, while 

 the counterweight Q, 

 raises it again. 



Figs. 1806 to 1809 

 represent the mode- 

 rately high (dcmi- 

 Jiauts, or half-blast) 

 furnaces employed in 

 the works of the Lower 

 Hartz, near Goslar, for 

 smelting the silvery 

 lead ore extracted 

 from the mine of 

 Eammelsberg. 



Fig. 1806 is the 

 front elevation of the 

 twin furnaces, built in 

 one body of masonry ; 

 fig. 1807 is a plan 

 taken at the level of 

 the tuyeres. 



Figs. 1808 and 1809 

 exhibit two vertical 

 sections ; the former in the line A, B, the latter in the line c, D, of fig. 1 807. In these 

 four figures the following objects may be distinguished : . 



