History of Iron
History of Iron
|The important part played by iron in the development of modern civilisation renders a study of the history of iron one of peculiar interest. In whichever direction we turn we are confronted by articles of iron, large and small, essential and ornamental. It is iron in some form or other that constitutes the framework both of our railways and of our mercantile marine. Without these rapid means of transport the huge populations of London and our larger cities could not be fed and supplied with the necessaries of civilised life as we know it to-day. Again, reinforced concrete, the building material of the future, owes what strength and adaptability it possesses almost entirely to its iron frame, and as our supplies of building stone become depleted we shall be driven to placing increased reliance upon this material. Of all the metals known to science, iron takes the foremost place in the service of man. Indeed, the wonderful progress that has been made during the last hundred years would not have been possible had not the earth possessed an abundant supply of iron or its ores.|
At the dawn of the human era man would seize upon any stones, branches, or other hard materials lying at hand for purposes of offence, defence, or the chase. Later on it would occur to him to improve upon the natural shapes by chipping, and he would soon discover that flint is particularly amenable to such treatment. Thus would originate the flint weapons and tools which have been discovered in large quantities in modern times, and which antiquaries have made use of to throw interesting light upon the manner in which primitive man lived during what has been aptly termed the Stone Age.
In all probability during his search for suitable stones early man occasionally stumbled across meteoric iron. Finding that it did not crack on being hammered, that it possessed great tenacity and admitted of being rubbed to a fine, hard edge, he would prepare from it his most valued weapons.
This does not constitute the beginning of what antiquaries term the Iron Age, for man at this period did not recognise any relationship between metallic iron and the red or brown earthy haematites around him. He regarded the iron merely as a particularly useful but unfortunately rare kind of stone, and not as a substance that he could manufacture for himself.
Interesting side-lights on the customs of prehistoric man are afforded by the behaviour of his modern representatives in uncivilised countries. Thus Ross in his Arctic explorations in 1818 came across certain Eskimos who carried knives consisting of blades of meteoric iron set into bone handles. The pieces of metal had been detached with great labour from the softest of three masses of metal of meteoric origin at Melville Bay, and had then been cold worked with stone hammers.
It has been urged that meteoric iron is too scarce to have ever been used to any appreciable extent by prehistoric man. This is hardly the case, however, for some 246 tons of the metal are known to science, and in prehistoric times meteoric iron would be even more plentiful than now inasmuch as the accumulations derived from meteoric showers of the previous ages could be drawn upon. As the metal, owing to its nickel content, is usually highly resistant to corrosion, it would not decay so rapidly by exposure as the ordinary manufactured metal.
Ages elapsed before man discovered that certain " stones," on being heated in a fire, yielded a new " stone " capable of being hammered into useful shapes, and differing from the original stone in most of its other properties. This new product is now called copper or bronze, according to its composition. At first, no doubt, it was a matter of accident whether bronze or copper was produced. In districts such as Cornwall, where copper and tin ores occur in association, they would be reduced together as one and the same, yielding what may be termed a " natural bronze." In Hungary, where copper ores are associated with those of antimony, early implements consist of an alloy of copper containing up to 4-5 per cent, of antimony. Similarly Egyptian implements contain arsenic, whilst those from Germany contain nickel.
The discovery that bronze is not obtained from a single ore but from a mixture of at least two ores represents a high standard of metallurgical knowledge, soon to be followed, if not indeed already preceded, by the discovery of iron. The question now arises as to how many years iron - whether native, meteoric, or manufactured - has been known to and used by different peoples. Just as the nations to-day differ in the relative degrees of their civilisations, so in past ages some of the peoples were living in their stone age whilst others were using implements of bronze and yet others had become familiar with iron. Thus Britain was passing through her stone period at a time when iron was already known in Assyria, in Egypt, and probably also in China. Again, at the time of the Roman invasion of Britain the southern tribes used bronze implements and were familiar with iron, whilst the northern tribe of Brigantes was still in their stone age. Iron was known in Egypt at least some 3500 в.с., although it did not come into common use probably until the fifth or sixth century в.с. Possibly the iron found its way thither from Ethiopia, where iron smelting was probably practised at an earlier date than in Egypt. During blasting operations within the Great Pyramid at Gizeh in 1837, an iron tool was found, which, if coeval with the pyramid, proves that history of iron starts in Egypt at the time of the Fourth Dynasty - that is, some 5500 years ago.
The first general group of iron tools found in Egypt dates back to the time of the Assyrian Invasion of 666 B.C., and was found at Thebes. The Assyrians themselves appear to have made chain mail about 900 в.с.
The Israelites were familiar with iron, and several interesting allusions to the metal occur in Holy Writ. Og, King of Bashan, с. 1200 в.с., is stated to have had an iron bedstead. It is generally accepted that iron was introduced into Palestine about this time by the Philistines, who were a far more cultured race than the Israelites, with whom they were constantly coming into conflict.
The oldest examples of iron used in Palestine are two wedge-shaped lumps found in the famous water passage at Gezer. The passage was sealed up about 1450 to 1250 в.с., several hundred years before the use of iron became general in Palestine; but although these are simply stray pieces of metal, they show that iron was known prior to these dates. Excavations at Gezer, Lachish, and Megiddo have brought to light numerous tools, weapons, and ornaments of iron, dating in some cases as far back as the time of David, namely, about 1000 в.с. An interesting example is that of a ring cemented to a finger-bone by rust, showing that it had been used for personal adornment.
It is not improbable that India acquired her knowledge of iron from Babylon; at any rate iron was worked in India at an early date. From a passage in the Black Yajuveda it would appear that some form of iron cannon was used in the Vedic Age, namely between 2000 and 1000 в.с. Between 500 and 200 в.с. iron appears to have been in quite common use, particularly for war weapons.
The famous pillar at Delhi has frequently been described, and owing to a regrettable series of errors the date of 912 в.с. has repeatedly been assigned to it. In reality it only dates back to about a.d. 300. It is 23 feet 8 inches in height, 22 feet being vertically above ground and 20 inches below. Its upper diameter is 12½ inches; its lower, 16½ inches; whilst its total weight is approximately 6 tons. The legend connected with this famous pillar asserts that the metal had been driven so deep into the ground that it had pierced the head of the king of serpents who supports the earth. It had thus a remarkably sure foundation. A Rajah doubted this and ordered the pillar to be dug up, with the result that its end was observed to be moist with the serpent's blood. On attempting to replace the pillar, however, it was found impossible to transfix the wily reptile, and the pillar, in consequence, remained loose and shaky, symbolic of the Rajah's faltering faith. It has been suggested that the city of Delhi owes its name to the pillar, the Hindoo term being Dhelli, or unstable. Sanskrit authorities are inclined to the opinion, however, that the word Delhi means the Heart's Delight, and has nothing whatever in common with the pillar. A remarkable feature of the pillar is its freedom from rust. This is no doubt due to some peculiarity of its surface layer, for pieces broken away appear to rust with ease. Hadfield analysed one such sample, and found it to contain: -
The high phosphorus and low carbon, sulphur, and manganese contents all tend towards reduction of corrodibility, but do not suffice to explain the general immunity of the pillar from corrosion. It has been suggested that the employment of stone anvils may have siliconised the surface and thus rendered it less susceptible to corrosion.
Turning now to Europe, it appears that Greece was the first country to use iron, namely, about 1400 в.с. Homer (в.с. 880) was thoroughly familiar with the metal, and frequently alludes t6 it in both his Iliad and Odyssey. Iron, gold, and bronze are repeatedly mentioned as indicative of wealth at the time of the Trojan war, which was fought at the transition of the Grecian bronze and iron ages, namely, с. 1400 to 1200 в.с.
It is an interesting observation that although Homeric agricultural implements were made of iron, the weapons were made of bronze with but two exceptions. The explanation appears to be that when iron was first made its quality was uncertain. Warriors, therefore, refrained from using it until artificers had gained sufficient experience to produce a reliable metal.
It is said that Pheidon deposited in the Herseum certain iron bars that had, prior to his time, namely, в.с. 600, served as money; and Waldstein, during his excavations at this site, discovered a bundle of iron rods which are believed to be the remains of Pheidon's gift.
The close of the Minoan age in Crete, c. 1400 to 1100 B.C., was the period of transition from bronze to iron in that island, and coincides with the Homeric age referred to above.
The Romans, several centuries later, were skilled metallurgists, and developed to a remarkable extent the iron resources of their empire. The Roman history is closely related to the history of iron. Pliny, who compiled his famous Natural History nearly two thousand years ago, gives a considerable amount of information relative to the ores of iron and the properties of the metal. He discourses at considerable length upon the tendency of the metal to rust. " Nature," he writes, "in conformity with her usual benevolence, has limited the power of iron by inflicting upon it the punishment of rust, and has thus displayed her usual foresight in rendering nothing in existence more perishable than the substance which brings the greatest dangers upon perishable mortality."
Pliny was also aware of the fact that some kinds of iron are less resistant to corrosion than others, and specifically mentions a species that "is more particularly liable to rust." He further states "that there is in existence at the city of Zeugma, upon the Euphrates, an iron chain by means of which Alexander the Great constructed a bridge across the river; the links of which that have been replaced are attacked with rust, while the original links are totally exempt from it."
This passage is remarkable as being a very early, if not indeed the earliest, statement of the relative corrodibilities of two kinds of iron.
The Britons were familiar with iron for at least a century prior to the Roman invasion of 55 b.c., South Wales being regarded as possibly the early home of the iron trade. Caesar mentions that the Britons used iron bars for currency, probably employing them for purposes of exchange, marriage portions, etc., in a similar manner to that in which the loggoh kullutty (iron spade-like articles) of the natives of Central Africa or the iron ingots of Cambodia are used at the present day. Some of the bars may be seen in the British Museum, whilst others, found near Worcester, are lodged in the Museum of that city. In appearance they resemble swords, having a flat and slightly tapering blade, with blunt edges, and a rude kind of handle formed by turning up the edges at one end. Two of the bars were examined by Gowland, who gives the following analyses: -
|Bar A.||Bar B.|
|Silicon||0.09 %||0.02 %|
|Phosphorus||0.69 %||0.35 %|
Bar A, examined under the microscope, revealed a structure similar to that exhibited by meteoric iron, whilst Bar В resembled iron produced by direct reduction from ore and forged from a bloom.
The bars have lost somewhat in weight in consequence of rusting, but, making allowances for this, the weights appear originally to have approximated to 309 grams or to some multiple or sub-multiple of this amount. In all, six different denominations have been found, of the following presumed standard weights: -
|Quarter unit||77 grams|
|Half unit||154.5 grams|
|Unit and one half||463.5 grams|
|Double unit||618 grams|
|Quadruple unit||1236 grams|
The reason for choosing the third weight, namely 309 grams, as the unit, and not the smallest weight, namely 77 grams, lies in the fact that in the Cardiff Museum is a bronze weight, which was found in association with enamelled bronze ornaments of Late Celtic character, near Neath in Glamorganshire. On the top of this weight is engraved the figure 1, and it weighs 309 grams. Another similar weight made of basalt, and also marked with a 1, is to be found (or was, prior to 1914) in the Mainz Museum.
These relics suggest that not merely was there a standard British weight corresponding to 309 grams, but that the same standard had been adopted throughout a large portion of Europe.
Boadicea was familiar with the use of iron, and the wheels of the early British war chariots were encircled with iron tyres, as is proved by remains found in Yorkshire, although it is very doubtful if they were fitted with scythes for laming hostile infantry, as was at one time believed. Undoubtedly many of the weapons wielded by Boadicea's troops against the Romans, a.d. 61, were also made with or strengthened by iron.
History of iron in England was developed during Roman times with a considerable iron trade was established in Britain. In a.d. 120 Hadrian established an arms factory at Bath, where iron from the Forest of Dean was worked. But in the unsettled periods immediately succeeding the Roman occupation the industry lapsed, to be revived again shortly before the Norman Conquest. This latter invasion produced such an upheaval in the country that the trade again declined until about the fourteenth century.
In 1350 or thereabouts cast iron was produced in Sussex, which county was at that period one of England's most important centres of the iron industry. The introduction of cast iron made it possible to utilise our ores to far greater advantage than would otherwise have been the case, and constituted an important advance in the metallurgy of iron. It was in the little Sussex village of Buxted that "Master Huggett and his man John, They did cast the first cannon," and many of the village churches and churchyards are graced by iron tombstones which date back several centuries.
Prior to 1653 there were 42 iron forges in Sussex, and 27 furnaces. The industry employed some 50,000 men and furnished the main supply of ordnance for national defence. About this time, however, the fuel shortage began to be serious, the supply of charcoal becoming very scarce. Before 1664 the number of furnaces was reduced to 11, and in 1667 the forges numbered only 18. It was not until 1809, however, that the last Sussex forge was extinguished, namely at Ashburnham.
Towards the close of the eighteenth century there was considerable improvement in the trade in other parts of the country, for coke was now being used. In 1790 England possessed no fewer than 81 coke and 25 charcoal furnaces. In 1917 the total number of blast furnaces was 496, and of these an average of 324 were in blast at any moment during the year. The enormous growth in the output of pig iron since 1740 is well illustrated by the following table.
Production of Pig Iron in the United Kingdom
|Year.||Pig Iron. Tons.||Year.||Pig Iron. Tons.|
The output for 1913 constituted a record up to the outbreak of war in 1914, in which latter year the production fell by about 10 per cent, and remained at approximately 9 million tons until 1919 - the latest returns available at the time of writing, - in which year there was a marked decline in production.
The world's production in tons of coal, iron ore, pig iron, and steel for 1913 - the last year for which complete records are available - is given in the following table, and indicates the enormous quantities of fuel, ore, and metal annually handled, and their consequent importance to modern civilisation.