938 



IRON 



1214 



The second operation is executed by cleaning the basin, removing the slags, cover- 

 ing the basin anew with 2 or 3 brasqucs (coats of pounded charcoal), and piling up to 

 the right and the left two heaps of charcoal-dust. Into the interval between tin-so 

 conical piles two or three baskets of charcoal are cast, and on its top some c;i' 

 the reduced crude metal being laid, the blast is resumed. The cakes, as thoy heat, 

 undergo a sort of liquation, or sweating, by the action of the earthy glasses on the 

 unreduced black oxide present. Very fusible slags flow down through the mass ; and 

 the iron, reduced and melted, passes finally through the coals, and falls into the slag 

 basin below. To the first parcel of cakes others are added in succession. In pro- 

 portion as the slags proceeding from these run down, and the melted iron falls to 

 the bottom, the thin slag is run off by an upper overflow or chio hole, and the reduced 

 iron kept by the heat in the pasty condition, remains in the basin : all its parts get 

 agglutinated, forming a soft mass, which is removed by means of a hooked pole in 

 order to bo forged. Each lump or bloom of malleable iron requires 3 hours and a half 

 for its production. 



The iron obtained by this process is in general soft, very malleable, and but little 

 steely. In Corsica four workmen are employed at one forge. The produce of their 

 labour is only about 4 cwts. of iron from 10 cwts. of ore and 20 of charcoal, mingled 

 with wood of beech and chestnut. Though their ore contains on an average 65 per 



cent, of iron, only about 40 parts are 

 extracted ; evincing a prodigious waste, 

 which remains in the slags. 



The difference between the Corsican 

 and the Catalonian methods consists 

 in the latter roasting the ore at a 

 distinct operation, and employing a 

 second one in the reduction, aggluti- 

 nation, and refining of the metal. In 

 the Catalonian forges, 100 pounds of 

 iron are obtained from 300 pounds 

 of ore and 310 pounds of charcoal; 

 being a produce of only 33 per cent. 

 It may be concluded that there is a notable loss, since the sparry iron ores, which 



are those principally smelted, 

 contain on an average from 54 

 The 



to 56 per cent, of iron. 

 same ores smelted in the ordi- 

 nary blast-furnace produce 

 about 45 per cent, of cast iron. 

 In some parts of America, 

 particularly in the States of 

 Vermont and New Jersey, the 

 Catalan forge was at one time 

 employed for smelting the rich 

 magnetic ores which there 

 abound. The form of this fire 

 (which is nearly imiform every- 

 where), and the manipulation 

 with it in America, is" thus 

 described by Overman : The 

 whole is a level hearth of stone- 

 work, from 6 to 8 feet square, 

 fig. 1214, at the corner of which 

 is the fireplace, , from 24 to 30 

 inches square, and from 1 5 to 1 8, 

 often 20, inches deep. In>i<!c it 

 is lined with cast-iron plates, the 

 bottom plate being from 2 to 3 

 inches thick. Fig. 1215 repre- 

 sents a cross section through 

 the fireplace and tuyere, commonly called tue iron ; d represents the fireplace, -which, 

 as remarked above, is of various dimensions. The tuyere b is from 7 to 8 inches 

 above the bottom, and more or less inclined according to circumstances. The blast 

 is produced by wooden bellows of the common form, or more generally by square 

 wooden cylinders, urged by water-wheels. The ore chiefly employed is the r 

 lised magnetic ore. This ore very readily falls to a coarse sand, and when ; 

 varies from the size of a pea to the finest grain. Sometimes the ore is employed 

 without roasting. In the working of such fires much depends on the skill and 



