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History of Copper

Copper has been an essential material to man since pre-historic times. In fact, one of the major "ages" or stages of human history is named for a copper alloy, bronze. Copper and its many alloys have played an important role in many civilizations, from the ancient Egyptians, Romans to modern day cultures around the world. Here, you will find a number of reference materials detailing the role that copper has played throughout human civilization for thousands of years.
Resources

60 Centuries of Copper: Intended for the reader who is interested in the general history of copper mining, the development of metal-working processes and the uses of copper through the past six thousand years. Based on Sixty Centuries of Copper by B Webster Smith which was published by the UK Copper Development Association in 1965.

The History of Copper in the U.S. covers the history of copper production and consumption throughout American history to present day.



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60 Centuries of Copper

By B Webster Smith

The story of copper and its principal alloys, bronze and brass, is virtually a chronicle of human endeavor since man emerged from the Stone Age. The ubiquity of the copper metals and their contribution to every civilization since Sumeria and Pre-Dynastic Egypt gives them a unique position in the history of technology.

This section is based on Sixty Centuries of Copper by B Webster Smith which was published by the UK Copper Development Association in 1965. Based on another UK CDA publication, Copper Through the Ages, Sixty Centuries of Copper is intended for the reader who is interested in the general history of copper mining, the development of metal-working processes and the uses of copper through the past six thousand years. The scope of the subject is so enormous that some sections have been covered only briefly, but it is felt that the book will be a useful introductory guide to students of history, particularly since the teaching of history has been broadened to embrace the origins of applied science. It should also help metallurgists, architects, industrial designers, engineers and other technologists to appreciate the part played by the copper metals in the past and recognize their potential contribution to future advances in civilization. The book traces the links between man's early uses of copper and the applications of today, and thereby outlines a continuous record of satisfactory service in which new uses for copper have been found in practically every century.


Introduction

Copper was the first metal used by man in any quantity. The earliest workers in copper soon found that it could be easily hammered into sheets and the sheets in turn worked into shapes which became more complex as their skill increased. After the introduction of bronze, a wide range of castings also became possible. Many of the illustrations on this site serve to show man's progress as a metal-worker, culminating in the priceless inheritance of the Renaissance craftsmen. But copper and its principal alloys, bronze and brass, have always been more than a means of decorative embellishment. Although iron became the basic metal of every Western civilization from Rome onwards it was the copper metals which were used when a combination of strength and durability was required. The ability to resist corrosion ensured that copper, bronze and brass remained as functional as well as decorative materials during the Middle Ages and the successive centuries through the Industrial Revolution and on to the present day.

Watt's steam engines, which ushered in the modern world, depended largely on iron and coal, with copper and its alloys making a lesser yet significant contribution, but with the subsequent development of electrical power copper proved to be the metal par excellence. The early decades of the 19th Century saw the foundation of the Electrical Age and thereafter the demand for copper increased tremendously. Britain was the major producer for much of the 19th Century but new mines were opened up in U.S.A., Chile, and later in Africa, until in 1911 the world's output of smelted copper for the first time exceeded a million tons per annum. With the increase in all branches of human activity which followed the Industrial Revolution new important uses were found for copper and advances in metallurgical knowledge led to the introduction of many new copper alloys.

Today more than 5 million tons of copper are produced annually and the copper metals are playing an increasingly vital part in many branches of modern technology. The ductility of copper, which led to its use for water piping in ancient Egypt, is illustrated by the countless thousands of miles of copper tube in contemporary plumbing and heating systems: the corrosion resistance of copper, which induced the Romans to use it for sheathing the roof of the Pantheon, is today verified by the thousands of copper roofs on modern buildings large and small; and the electrical conductivity of copper, which was utilized by Michael Faraday in his epoch-making experiments, remains the key to modern power generation.

These are but three of the examples outlined on this site where present applications are indissolubly linked with the past, but copper is also an essential material of the future. Solar heating, large-scale desalination of water, the linear motor are all innovations where copper will make an increasingly important contribution. The known reserves of copper ore are ample for all envisaged requirements, and continuous metallurgical research promises to provide new alloys possessing even superior properties to meet the exacting demands of the technology of the 21st Century.

Man Becomes Metal-Conscious

In the New Stone Age men first learned to live peaceably together in pastoral and agricultural communities, from which fixed settlements arose, long before they became metal-conscious. They practiced agriculture, had numerous domestic implements and were skillful potters, artists and artisans in bone and certainly also in wood, when somewhere they became attracted by the shining particles of free gold in shallow riverbeds. They seem to have quickly discovered that this remarkable stone, as they regarded it, could be beaten into thin plates and even fashioned into pins; and perhaps these discoveries started an inquisitive search which led them to find, first the curious lumps of native copper, although it was probably always scarce, and then the much more abundant bright green 'stone' malachite and its close blue associate azurite. Both these copper carbonates not only catch the eye but are also easily detachable from the ground. No doubt men also learned early to distinguish "fool's gold"* the bright yellow iron pyrites and the very similar yellow copper ore, copper pyrite* from the true gold with which they may excusably have mistaken it at first. Our knowledge of Man's earliest interest in metals in the dawn of prehistory will never be more than hypothetical, but it can be asserted more confidently that, so far as copper is concerned, these events occurred during the Fifth Millenium B.C.; hence Man's knowledge of copper must date back for at least six thousand years.

During that period, two great rivers, the Euphrates and the Nile, each nourished a considerable civilization near its mouth. The former was probably of greater antiquity, since it was responsible among other things for developing the art of brick manufacture which was originally unknown in Egypt. There were two kingdoms on the lower Nile, Upper and Lower Egypt. In general terms the date of the early Sumerian civilization, which clustered around Ur and other cities, can be set at 3500 to 4000 B.C., and Pre-Dynastic Egypt covered the same period or possibly a little later. King Menes, from whose reign all Egyptian chronology* is taken, conquered Lower Egypt and welded the two parts of the Nile people into one nation, around 3200 B.C.

A whole series of other but less important centers of early civilization in the Near and Middle East has been unearthed by archaeologists during recent decades, but they are certainly younger and their dates extremely hypothetical.

Two other major centers of mankind lay farther afield, in Hindustan and China. With immense populations and abundant agricultural resources, these civilizations also have their origins in the distant past; but the Chinese records cannot be definitely dated earlier than the Third Millenium B.C., and the civilization of India probably first began to flourish during that period. Neither appears to have derived much from the Sumerians or Egyptians, since geographical barriers, particularly in the case of China, precluded any interchange of culture.

It is against this historical background that one must try to unravel the earliest history of copper.
* In this publication, the chronology at present adopted by the British Museum is followed.

The Sumerians and Chaldeans

Copper probably first came into use as the earliest non-precious metal employed by the Sumerians and Chaldeans of Mesopotamia, after they had established their thriving cities of Sumer and Accad, Ur, al'Ubaid and others, somewhere between 5,000 and 6,000 years ago. These early peoples developed considerable skill in fabricating copper and from these centres the rudiments of craftsmanship spread to the river-dwelling people of Egypt, where it continued to flourish for thousands of years long after their own civilization had degenerated.

Although the Sumerian art-forms were rather crude, many of the objects they produced were wonderfully life-like. In other respects this group of city states was at first more advanced than those of the Nile. They had a system of writing, an art which the Egyptians only acquired late in their history. They made surveys, kept exact land records, and were capable mathematicians. If we accept the chronology which is favoured at present by the British Museum, their greatest period ranged between 2800 and 2000 B.C. Bronze pots and mixing trays have been found at al'Ubaid, near Ur (c. 2600 B.C.), also silver ones of the same date, besides silver-spouted bronze jugs, saucers and drinking-vessels which were probably used for ceremonial purposes. Still earlier are some copper chisels and other tools from Ur, likewise copper razors, harpoons, cloakpins and other small articles. Far older than any of these are some copper arrows and quivers, together with prehistoric Sumerian copper spearheads, all of which have successfully survived the test of time.

The Sumerians were masters of sculpture and some splendid examples of their art may be seen in London. Thin copper sheets were beaten and shaped on a wooden background with a bitumen lining-a favourite design was a bull's head. These figures were attached by copper clamps to the walls of buildings, notably at al'Ubaid (c. 2800 to 3000 B.C.); sometimes they were fastened by nails or copper wires set in bitumen. To this stage belongs the magnificent Imdugud Relief (Fig. 1) which represents a lion-headed eagle holding two stags by their tails. The whole relief is of beaten copper within a copper frame and on a wooden background, the overall dimensions being 7 ft 9.5 in. long and 3 ft 6 in. high. The stags' antlers, which are in high relief, were made of wrought copper and then soldered into their sockets with lead.



Even at such an early date, these people adopted the practice of burying under the foundations of buildings a record concerning the builder. Small bronze or copper figurines were likewise buried there at the same time. One such record, in the form of a copper or bronze peg 12 in. long, relates to a king of the First Dynasty at Ur. A more remarkable one shows a god holding a peg about 6 in. long; this came from the temple at Ningursu (c. 2500 B.C.).

Another proof of the indestructibility of copper is connected with a Sumerian wooden sled which was intended to run on the sands; it is picturesquely known as 'The Queen's Sledge'. This sled was drawn by two oxen wearing large copper collars, while the reins had copper studs. A Sumerian soldier who presumably marched alongside this equipage wore a copper helmet.

The Ever-Changing Pattern

As civilization progresses new materials are developed but older ones are rarely discarded; rather are they used more for specialized purposes, particularly if they are comparatively scarce. This was the fate of bronze in Rome, after the introduction of iron smelting about 600 to 700 B.C. In this case the durability of copper and its principal alloy, bronze, and their attractive appearance, ensured continuing use of both metals although on a more limited scale. Moreover, the discovery soon afterwards of a new copper alloy, brass, opened up endless fresh opportunities for the coppersmith's art.


The Background

Ruined by its own prosperity and universal dominion, the later Roman Empire fell into inevitable decline. Under the growing onslaughts of the northern barbarians, the weak and degenerate Western Empire tumbled into ruins and carried the wreckage of its civilization with it. For nearly a thousand years the world witnessed the slow transformation of the newcomers from forest tribes and raiding nomads into organized states, who eventually became the dominant powers of the Middle Ages - the French, Germans, Burgundians, Lombards, Anglo-Saxons, Danes and Northmen. It was the Normans, the strong and able successors of the Northmen who had settled in Northern France, who eventually established their customs and feudalism over most of Europe from Britain to the southernmost tip of Sicily and even into the Near East. Only the Church continued to grow and to flourish throughout this long period, firmly held together by monasticism, and retaining within its bosom many relics of the old learning and the seeds of many trades. For the monks were not mere saints, but very practical people, with a keen eye for their own interests, a subtlety of mind that was quite beyond the mental range of their nominal rulers, a genius for picking out the best sites and acquiring the most valuable lands for their abbeys, and the highest talent in church building that the world has seen. It is amusing to note how the Venerable Bede, after upbraiding a drunken monk for his misbehaviour, excused him because he was a first-class smith!

Such were the Middle Ages, a time when bronze had given place very largely to iron, when agriculture was paramount, when internecine wars were common, and industries few and comparatively simple.

In Britain the Anglo-Saxons, who were skilled woodworkers, especially in oak, and also highly skilled blacksmiths, took little account of metals other than gold, silver and iron. During many centuries their basic currency was the silver penny, although a few copper coins were occasionally struck, notably in Mercia during the 8th Century. Inevitably in this period the art of coppersmithing declined, even on the Continent.

The impact of the Norman Conquest profoundly altered the English way of life. The feudal system, with its highly organized scale of duties; the institution of settled King's Laws and their savage enforcement; and the acquisition of power by individual barons, around whose castles clustered all the people who sought their protection, encouraged the growth of towns and a middle class of traders and guildsmen who steadily forced their way to independence. The tremendous impact of the Mediaeval Church, with all its panoply of ceremony, colour and wealth, encouraged certain trades and stimulated arts and crafts though not learning. Nevertheless for a long time England depended mainly upon wool, beef and mutton, and drew most of her metals from the Continent. Brass, in particular, was regarded with great favour in this country, and was known for a long time under its French name of 'Latten'.


Its Effect on Copper Mining

The Industrial Revolution brought about a tremendous change in the production of copper and its alloys. In the first place, an insistent demand arose for more and better raw material. In 1586 Ulrich Fosse, a German who was working the Cumberland copper mines, boasted that he could smelt 560 tons of copper ore in forty weeks. The 17th and 18th Centuries saw a vast improvement in this rate of output, largely arising from a quicker removal of impurities from the ore. By 1717 the Landore Works at Swansea comprised three large buildings, one of which was devoted solely to calcining. There were also thirty smelting furnaces for copper, lead and silver, a refining house, a test house and other outbuildings. (20)

In 1794 the Mines Royal at Neath Abbey were smelting 230 tons of copper ore per week to give 18 tons of copper. They used thirty-eight furnaces which consumed 315 tons of coal in the operation. The presence of good coal, in fact, was one of the reasons why the Swansea district became the centre of this industry; charcoal had been used right down to 1688 although as early as 1632 Edward Jorden discovered a new method of smelting by using pit coal, peat and turf as a fuel, and four years later Sir Philip Vernatt was granted a patent for the use of coal alone for that purpose.

Swansea was also an excellent seaport and was accessible to ships from all parts of the world which could bring ore from mines abroad.

During the 18th Century production in the nearby Cornish mines increased and a high output was sustained due to the introduction of steam pumps to remove the water from the diggings. This was the first use of steam power in mining and arose from the inventive mind of Thomas Newcomen, a Dartmouth blacksmith. Thus the Swansea district with its coal and commanding position became the greatest centre in the world of copper smelting and refining, a distinction which it retained until the latter part of the 19th Century. But a terrible price was paid; the local atmosphere in what had formerly been the beautiful green valleys became so foul with sulphurous fumes that it was said that if the Devil were to pass that way he would think he was going home. (21)

The cost of copper, in those days, was very great. In 1714 cake copper, unrefined, fetched £100 per ton, and plates as they came from the battery works cost £140 to £150 per ton. In 1694 Swedish copper, which was then regarded as high quality, cost £168 per ton. These figures, currency for currency, far exceed modern prices. On the other hand, the entire English output of English copper at that date was only about 100 tons per annum.
20 ALEXANDER, W.O. Development of the Copper, Zinc and Brass Industries in Great Britain from A.D. 1500 to 1900 Murex Rev. (1955), 1, (15), p. 399.

21 Ibid. p. 408.

Dawn of a New Science

When the great Elizabethan experimenter William Gilbert, after many years' work, published his book De Magnete, and first defined scientifically a number of fundamental ideas about magnetism and electricity, he started a chain of operations that eventually led to the vast, dynamic and complex electrical engineering industry of today which consumes two million tons of copper annually. It was Gilbert incidentally who coined the word 'Electrica' from the Greek word elektron, meaning amber, a substance which featured in his experiments.

Electrical engineering in the industrial sense is only about a hundred years old and followed from Faraday's epoch-making discovery of electromagnetic induction in 1831; its roots, however, extend back much earlier, even before Volta's famous 'pile' of 1800, when the relative values of metals as conductors of electricity were well known. The success achieved by using copper in these classic experiments led to its general use in this field long before the theoretical reasons were understood. Hence all the early experimenters soon found themselves using copper sheets and wires whilst brass, because of its non-magnetic properties and ease of working, was specified for structural parts.

A notable milestone in early electrical research was the invention of the Leyden jar in 1745. Two years later Sir William Watson, who was deeply interested in electrical phenomena, succeeded in transmitting a current 2410 feet across Westminster Bridge, using the River Thames as the return circuit. He also noticed that the effect was apparently instantaneous. Stephen Gray had already found that some bodies conducted electricity well, whereas others did not, the first conception of dielectrics; and in 1729 he used brass wire for the first known attempt to transmit an electric current. Thus began a series of experiments by a number of investigators to determine which were the best transmitters of the 'electric fluid', as it was called: it was soon proved that metals were the most successful and that of these, copper, even in its relatively impure state, was superior to all others except silver.

The Raw Material

At the beginning of the present century the world's annual demand for copper was about half a million tons; the United States produced about half this total, whilst Britain's output had fallen to a mere token figure. Today the annual consumption is now more than nine times as large. This dramatic rise in the intervening sixty years can be attributed partly to population growth but mainly to the tremendous technological advances which have received impetus from two World Wars. In the Second World War the demand for copper most certainly could not have been satisfied, but for an invention in 1921, when Perkins patented his process of chemical flotation. This made it possible to mine ores which, up to that time, had been regarded almost everywhere as worthless. Some attempts at flotation of crushed ores had been made ever since 1860, but the process only became commercially important after the 1914-18 war. 29
29 NEUBERGER, A. The Technical Arts and Sciences of the Ancients. (1930), p. 37.