Page:The American Cyclopædia (1879) Volume IX.djvu/404

390 IRON MANUFACTURE and describe the method of melting it. Inihe time of ^Eschylus (born in 525 B. 0.) the Cha- lybes were famous workers in iron, and Cha- lybia was called the mother of iron. Strabo, writing about the beginning of the present era, speaks of the iron mines of Chalcis in Eubooa as almost exhausted by the extensive mining operations of the Athenians. He also mentions iron brought from Britannia, and speaks of the mines of Elba, famous to this day, then called by the Greeks, from the blazing lire of its iron works, ^Ethalia. Pliny the Elder devotes two chapters of his " Natural History " (xxxiv. 14, 15) to an account of iron, its uses and manu- facture. He speaks of an iron statue of Her- cules by Alcon at Thebes, and bowls of iron in the temple of Mars at Rome ; of different qual- ities suited to different purposes, some being adapted for hardening into steel, or else pre- pared in another manner for making thick an- vils or heads of hammers ; and of the Serican, Parthian, and Norican irons. He was aware of the magnetic property of iron, and speaks of an iron statue of Arsinoe, sister of Ptolemy Philadelphus, which it was proposed to suspend in air, in a temple, by means of a vaulted roof of loadstone. Iron of great antiquity has been found in eastern countries. Belzoni describes the discovery, under the feet of one of the sphinxes unearthed by him at Karnak, of an iron sickle, which he considers to be at least as old as the age of the Ptolemies. It was of the same form as those depicted in the tombs at Memphis. At Memphis iron has been found in the ancient structures, and two pieces have been taken from the great pyramid of Gizeh. Layard discovered at Nimrud a large num- ber of articles showing great knowledge and skill in working this metal possessed by the Assyrians. Most of them, having been whol- ly converted into oxide, fell to pieces when touched. Among the objects found were ar- mor scales, daggers, shields, heads of spears and arrows, a pick, a double-handed saw, arti- cles of combined bronze and iron (the former having been cast around the latter), part of a stand consisting of an iron ring with three feet of bronze, &c. Iron ornaments of the ancient Chaldeans have been discovered, but no implements, showing that with them iron was still a precious metal. The most remark- able evidences of the progress made by the an- cients in iron metallurgy are found in India, although, strangely enough, the art as prac- tised in that country at the present day is ex- tremely rude and simple. In the remains of temples are found iron beams, one of which measures 24 ft. in length and 8 in. in section. The famous Delhi wrought-iron pillar, called Cuttub Minar, at the mosque of the Cuttub Shaw, is upward of 48 ft. long. Its lower di- ameter is about 16$ in., its upper diameter 12 in. It contains upward of 80 cubic feet of metal, and weighs 17 tons. It is supposed to have been erected A. D. 319. How such a forging could have been effected is a mystery. The only probable suggestion hitherto brought forward is, that it was made by welding each bloom directly to the previously made bloom, and that as the column grew in height the furnace was elevated by throwing up a mound of earth, so that the top of the pillar formed the bottom of the furnace, and the blooms as soon as formed were directly welded to the top of the still glowing pillar. From some obscure remarks by ancient writers it has been inferred that cast as well as wrought iron is of great antiquity ; and it has been suggested that the ancients practised the art of steel making described by Vanoccio Bizingucco in 1540 and by Agricola shortly after, which consisted in im- mersing pieces of soft iron in a bath of molten iron. This we can only conceive possible by sup- posing the metal bath was well carbonized. The evidence for this is however very slight. Aris- totle writes : " Iron may be cast so as to be made liquid and to harden again ; and thus it is they work to make steel." Pliny in describing the process of iron smelting says : " It is a remark- able fact that when the ore is fused, the metal becomes liquefied like water, and afterward ac- quires a spongy brittle texture." This may re- fer, however, to the liquefaction of the cinder. Diodorus gives a clearer and more comprehen- sible account of the smelting process on the island of Elba, and says nothing about molten metal : " The workmen employed first cut the stone in pieces, and then melt them in furnaces built and prepared for the purpose. In these furnaces the stones, by the violent heat of the fire, are melted into several pieces in form like great sponges." This description might equally apply to the bloomary practice of the present day. Though so little is known of the .meth- ods employed by the ancients for the reduction of iron from its ores, it is not improbable that they were similar to those still in use in east- ern countries, which have been practised from time immemorial. A low stack, either built of clay or excavated on the hillside, with open- ings at the bottom for draught of air or for an artificial blast, is all the apparatus required for the successful manufacture of iron. The fur- naces of India are usually from 3 to 6 ft. high and from 10 to 18 in. in diameter. The blast, supplied by bellows made of skins, is forced into the furnace through clay tuyeres. The furnace is charged with ore and charcoal alter- nately, until the requisite amount of ore has been added. After a blast, varying from 3 to 4 up to 18 hours, a mass of soft malleable iron mingled with cinder is removed from the fur- nace, either by breaking away the lower part of the stack, or by lifting the bloom out of the top with tongs. The weight of the iron bloom varies from 4 or 5 up to 200 Ibs. It is hammered while still hot, reheated and again hammered, until the greater part of the cin- der is expelled. The knowledge of the meth- od of reducing iron was probably introduced into Europe from the East, but when and by whom is unknown. Traces of early workings