"In this manner ore and fuel is supplied, and the bellows are urged for three or four hours, when the process is stopped: the temporary wall in front being broken down, the bloom is removed by a pair of tongs from the bottom of the furnace. It is then beaten with a wooden mallet, to separate as much of the seorim as possible from it, and. while still red-hot, it is cut through the middle, but not separated, in order merely to show the quality of the interior of the mass. In this state it is sold to the blacksmiths, who make it into bar iron. The proportion of such iron made from 100 parts of ore is about 15 parts."* From this iron the celebrated wootz steel is made by the natives of India in a manner equally rude and primitive. But their production has no superior, if it is equalled, and for the purpose of fine cutlery it is infinitely superior to the best English cast steel.
The Damascus blades, so renowned even in the Middle Ages, and still so much sought for by military men, are produced from bigots, like those of wootz, which come from Golconda. They are small and oblong, and when cut in two form two swords.
The blast-furnace for the production of pig iron does not seem to be of ancient inven tion. Though the air or wind furnaces of the early Britons produced cinder in abun dance, and perhaps as full of iron as the scoria; of wootz, the iron obtained from both was malleable. It does not appear where or when the blast-furnace was first made use of; but the frequent irregularity of the ancient forges or the present bloomery would naturally suggest the use of cast iron for many uses, since it often happens that those forges become deranged through the change of workmen, ores, or some other cause, and "pot-metal" is produced, which, of course, may be cast in almost any form by remelting, and can only be reduced to wrought iron by reheating, and the process used in bloomeries to reduce pig iron to bar. This, however, is not the invariable result of " green hands" or derangement. Sometimes nothing but a mass of cinder or " burned iron" is produced, of no value.
Whatever might have been the ancient mode of producing iron,—by the wootz oven, the wind-furnace, the Corsican hearth, or the Catalonian forge, the,forges allemandes of the French, or the Stuck-ofen of the Germans,—the mode most general in use during the modern ages and up to the present time, for the production of wrought iron direct from the ore, is that of the Catalan forge, and improvements on the same.
All other ancient methods of which we have any definite knowledge produce less iron from the same quantity of ores, and at a greater expense of labor.
The Corsican hearth produces a very soft, malleable iron, but a little steely. Four workmen are required at one forge. The product of their labor is only four hundred weight of iron from ten hundredweight of ore, and twenty hundredweight of charcoal mingled with wood of beech and chestnut, or about 40 per cent. from rich ores con taining 60 to 70 per cent. metallic iron.
The yield of the Catalan forge is much greater from the same amount and character of ores, with loss labor and fuel. Two men attend each forge, and produob four to five hundred pounds per day, with an equal amount of charcoal, and double the amount— or eight to ten hundredweight—of rich magnetic ores.
With good hematite ore, of about 50 per cent. average yield, a good blast and fair
charcoal, two good workmen will produce four hundred pounds of iron per day; but their average production will be about 300 pounds.
The common Catalan forge, or bloomery in general use, is usually a rude structure of coarse masonry, built without any regard to the economy of fuel, ore, or labor. If properly built, and operated by careful workmen, double the usual results might be produced.
As before stated, the exact date of the discovery of the use of cast iron cannot be definitely fixed. According to Dr. Percy, the first cannons of cast iron were manu factured in Sussex, in England, by Ralph Hogge, in 1543. But Hogge was assisted by a Frenchman named Peter Baude, who, it appears, had learned the art of producing cast iron in France. Rogge, assisted by one of his servants,—Johnson by name,—after wards made cannon of 6000 pounds weight.
Agricola, who died in 1555, wrote that "iron, smelted from iron-stone, is easily fusible, and can be tapped off." The elevation of the bloomery into the blast-furnace appears to have been first ac complished in England. It was probably in the early part of the sixteenth century. Mushet, however, concludes that the old blast-furnaces of the forest of Dean were erected in 1550.
Up to 1621, charcoal was used exclusively in the blast-furnace. But about this date Lord Dudley obtained a patent for smelting iron with mineral fuel. It was not, how ever, much used until tho discovery of its conversion to coke in 1730-35, when Abraham Parley, of Colebrook Dale, first used coke with success in the blast-furnace. But in 1740 during the change from charcoal to coke, the production of the English furnaces fell from 180,000 to 17,500 tons per annum.
The best yield of an improved and well-built blast-furnace, using charcoal with hot blast, is one ton of pig metal to every three cords of wood or 120 bushels of charcoal. But we have seen many instances where ten to thirteen cords of wood were used to pro duce a ton of iron in the rude Southern blast-furnace, and one instance where thirty cords were used! In the first case, where 120 bushels of charcoal are produced from three cords of wood, the charring or " coaling" is done in kilns, and 40 bushels of coal produced from one cord of wood ; but in the second the coaling is done in open " charcoal pits," in which an average production of 33 bushels per cord is considered a good yield, particularly when a limited number of " pits" can be coaled on the same "hearth." This expenditure of fuel is simply in the production of pig metal: to reduce it to bar iron nearly a third more coal is consumed than in the elaboration of the pig. That is, if 120 bushels produce one ton of cast metal, it will require 180 bushels to convert the metal to malleable iron under the same degree of improvement. But if it requires 333 bushels of charcoal to produce a ton of metal in the rude mountain-furnaces, it generally requires 500 bushels to elaborate the metal into bars under the same rude style of manufacture.
Under these circumstances, the improved Catalan forge is equal to the blast-furnace. But as improvements in the blast-furnace are now far in advance of the ancient forge, and likely to remain so, any comparison must be unfavorable to the latter, except in peculiar localities.