INTRODUCTION.

The Bronze Age

Mining

Brass.

Products in the House.

Design Implementation – Production Methods.

Uses of Copper and its Alloys.

New, Reproduction, Fake or Original?.

Analysis of Composition.

Dating Copper and Brass.

Registered Designs

INTRODUCTION

Copper and brass have been used for centuries for the production of functional, attractive items for the home.  These started with cookware and lighting products and soon included large quantities of useful, decorative items for all rooms.  The colour and comfortable warmth of the metals were highlighted by attractive, stylish designs that caught the imagination of the householders and the eyes of visitors.  Design trends have varied with fashion and have been frequently revived.  Today’s designers do well to study and perhaps obtain inspiration from products that are still appreciated years after they were made.

Pre-dynastic Egyptians knew copper very well and in hieroglyphs copper was represented by the ankh symbol also used to denote eternal life, an early appreciation of the lifetime cost-effectiveness of copper and its alloys.  The Greeks adopted a similar symbol  for copper as perhaps the most important of the thirteen elements that they knew.

The Copper Age

The earliest copper smelting furnace and workshop found so far is at Timma in Southern Arabah, Israel and dates from the Chalcolithic period in the 5^th millennium BC.  It has been accurately dated to 4460 BC and is near a site still used for mining.[i]

Pre-dynastic Egyptians knew copper very well and in hieroglyphs copper was represented by the ankh  symbol also used to denote eternal life, an early appreciation of the lifetime cost-effectiveness of copper and its alloys.  The Egyptians obtained most of their copper from the Red Sea Hills.

The older civilisation based on the Euphrates also new copper and well developed smelting techniques.  The earliest known artefacts made from smelted metal were copper, and excavations at Catal Huyuk near Konya in Southern Anatolia, showing slags derived from the smelting of copper, have been provisionally dated to as early as 7,000 BC.  Other civilisations in the Near and Middle East, Hindustan and China also developed the use of the vital metal.

Homer referred to the metal as ‘Chalkos’; the Copper Age is therefore referred to as the Chalcolithic Age.  Roman writings refer to copper as ‘aes Cyprium’ since so much of the metal then came from Cyprus.

The Bronze Age

Early workers knew that the addition of quantities of tin to copper would result in a much harder substance.  This alloy, bronze, was probably the first alloy made and found particular favour for cutting implements.  Many finds have proved the use of both copper and bronze for many purposes before 3,000 BC.

Some of the earliest bronzes known come from excavations at Sumer, and are of considerable antiquity.  The co-smelting of ores of copper and tin to make bronze would have been either accidental or the outcome of early experimentation to find out what kinds of rock were capable of being smelted.

An appreciation of quality in bronze depending on the tin content emerged only slowly.  Consistency of composition of bronzes dates back to about 2,500 BC at Sumer, with bronzes commonly containing 11 - 14% tin - reasonable evidence both of technological forethought and the appreciation of metallurgical and founding properties.  Indications of bronze production as far back as 2,800 BC come from places as far apart as India, Mesopotamia and Egypt, and make a single origin for bronze smelting significantly further back in time a strong possibility.

Trade by land and sea, and the succession of cultures and empires, had dispersed knowledge of the copper-based metals slowly but surely throughout the Old World.  By 3,000 BC it had spread across Europe and North Africa to the British Isles, and in other directions as far as India and China.  Copper, bronze, copper-arsenic, leaded copper, leaded bronze and arsenical tin bronzes were all known by this date in most parts of the Old World.

‘Oetzti’, the 5,000-year-old mummified man found in 1991 high in the Alps on the Italian-Austrian border was found with many implements including an excellent arsenical copper axe.  It seems that he was probably a coppersmith himself, since his hair had high concentrations of copper and arsenic, which could probably have come from no other source.

Alloys containing zinc were also emerging at this time, from Cyprus and Palestine, though the alloying is believed to have been natural in origin, due to the local ore containing some smeltable zinc minerals.  Alloys similar to modern gunmetals were being cast before 1,000 BC, though the proportions of copper, tin, zinc and lead were not well established.  Following the emergence of true brasses in Egypt in the first century BC, possibly from Palestine, the industrious and methodical Romans rapidly consolidated the knowledge and usage of copper, bronzes, brasses and gunmetals.

Bell founding originated in China before 1,000 BC and in time Chinese bell design attained good technical sophistication.  The technology spread eventually through Asia and Europe to Britain, where early evidence of bell making has been dated to around 1,000 AD, through excavation of a bell casting pit at Winchester.  Several important books were written during the Middle Ages concerning the extraction, smelting, casting and forging of copper.  These established that the casting and working of copper and its alloys had its origins in craft traditions and practices that had developed over several thousand years.  How much of this was originally handed down in writing is not known, since it is only from medieval times that the written tradition in technology is unbroken.  It is through the Christian monastic and Islamic cultural traditions that detailed accounts of these early technologies have survived.  The writings of the monk Theophilus in the 11th Century and of Georgius Agricola and Johannes Mathesius in the 16th Century, all describe in detail the metal producing technologies of their day.  Often these had changed little for centuries.

The output from the Bronze Age mines was considerable - an assessment based on old mine maps and studies of prehistoric workings at Mitterberg in the Austrian Alps indicated that about 20,000 tons of black copper had been produced there over the period of the Bronze Age.  In Britain, the most important Bronze Age mine was probably at the Great Orme near Llandudno in North Wales.  The earliest mines in Britain were in the Cork-Kerry area of Ireland, there were several more in Wales and important mines in England were at Alderly Edge, near Manchester.  Judging by the artefacts found, reserves in Scotland may also have been worked in Bronze Age times.  Many of these were in and near the Western Isles and the ease of shipping meant that this was the commercial centre of Scotland at this time

Black copper was the usual product of ancient smelting and contained about 98% copper.  It was traded as flat cakes weighing a few kilograms for later refining to purer copper by ‘poling’.

Significant engineering uses had been found for copper as early as 2,750 BC, when it was being used at Abusir in Egypt for piping water.  Copper and bronze were employed for the making of mirrors by most of the Mediterranean civilisations of the Bronze Age period.  Legend has it that the Greek goddess of Love, Aphrodite, appeared out of the sea of Cyprus looking at her reflection in a copper mirror.  This has been said to show that the oldest profession is, in fact, metallurgy.

The obliteration of Carthage by the Romans has obscured developments in Northern Africa at that time.  It is only quite recently that evidence of the considerable engineering skills of the Carthaginians has emerged, including the earliest known use of gear wheels, cast in bronze.  Bronze was used in many of the artefacts of every day Roman life - cutlery, needles, jewellery, containers, ornaments, coinage, knives, razors, tools, musical instruments and weapons of war.  The Roman invasion of Britain was probably strongly influenced by the need to secure the resources of copper and tin in Cornwall and copper North Wales at the Great Orme, Parys Mountain and elsewhere.  The pattern of use tended to be repeated wherever the smelting of bronze and copper was introduced, though necessarily on different time scales.  The New World and Africa lagged in these developments by 3,000 - 3,500 years because of the distance and isolation of these areas from the trade routes that loosely bound the ancient world.  In America, native copper was found in the Great Lakes region and was being worked and used by the locals long before the Europeans arrived.

Mining

The oldest methods for removing rock from underground mines were the sledgehammer and wedge and the equally ancient technique of fire setting. In the latter case a fire set up against a rock face would produce thermal stresses - the rock would either crumble naturally or could be shattered by water quenching. It was some time after the Islamic world introduced blasting powders to Europe in the 13th century, from China, that explosives were first used specifically for mining.

Middle Ages and Beyond

In Britain, some rich mines near Keswick in Cumberland were worked as early as 1250 and no doubt production continued in Cornwall and North Wales although not again of great importance to the economy until the early 18^th century.  The invention of printing increased the demand for copper because of the ease with which copper sheets could be engraved for use as printing plates.  In Germany, playing card designs were engraved on copper as far back as 1430.  Copper plates have long been adopted as the best means of engraving maps.  The first known maps printed from copper plates are two Italian editions, dated 1472, by the geographer Ptolemy. 

To reduce dependence on European copper and brass, the Society of Mineral and Battery Works was established in 1565 for the production of copper and brass artefacts in Britain.  They set up factories at sites throughout the country.  Besides naval needs for cladding and cannon, the main demand was for wire for the combs vital to the wool trade.  In 1568 a monopoly organisation, The Mines Royal, was set up by Queen Elizabeth I to undertake mining and extraction of copper in England and Wales.  Mining was re-developed in Cumberland at Keswick and in Westmorland.  The intention was to make the Country self sufficient and by 1625 it was possible to recognise this with a heavy duty on imports.   

Copper had been extracted at Parys Mountain in Anglesey since before Roman times.  The body of ore was so rich that water flowing from the mountain was rich in copper.  As early as 1579 there was an experiment to win this at low cost by the use of settling basins loaded with iron scrap.  This precipitated the copper very successfully and later became a standard technique.  Extraction of copper from sites on Parys Mountain was developed successfully by local and other businessmen.  In 1775, James Watt patented his design of steam engine.  This made it possible to pump water from mines much more economically.  It also increased demand for copper for boilers.  In 1787 a consortium was formed including Thomas Williams (Anglesey), John Vivian (Cornwall), Matthew Boulton and James Watt (Birmingham).  Their aim was the joint marketing of copper from Anglesey and Cornwall so that the price would provide venture capital to cover further exploration and extraction.  During the years 1819 to 1826 the output from Parys Mountain was over 9,000 tons of ore per year, yielding 600 tons of copper.  This made it the biggest copper mine in the world at that time.  The ore was initially shipped to Swansea for refining but as competition developed, also to Cheadle in the Peak District where Thomas Patton had set up in 1734 to refine the local ore from the land of the Duke of Devonshire.  Later it became economic to establish a new refinery near the docks at Liverpool.  Initially this dealt with ore from North Wales but later from other imports.

Copper has other important uses at sea, as copper sheathing of the hulls of wooden ships was introduced in the middle of the 18th century.  This was intended to protect the wood against shipworm when in warm seas.  It was found that it also kept the hulls free of barnacles and other marine growth, preventing the consequent severe drag that slowed the ships.  This enabled Nelson’s ships to spend many months on blockade duty and still be swift when battles commenced.  The tonnage of copper needed had a significant effect on the price in Britain and the prosperity of the industry.  Now, copper-nickel cladding can be applied to wood, polymer or steel hulls to prevent the fouling of ships operating at higher speeds. 

In the early 18th century Swansea was becoming a major copper centre and by 1860 was smelting about 90% of the world’s output.  Much of this was controlled by the Cornish Vivian family.  At first, Swansea obtained most of its ore from many mines in Cornwall and also Anglesey.  Mining of the rich deposit in the Great Orme at Llandudno was restarted.  Eventually the shafts went down to six levels.  The spoil heaps that were formed obscured evidence of the earlier Bronze Age workings but these have now been re-excavated and are an interesting visit.  Workings of a similar period have also now been found at Parys Mountain despite the large open pit resulting from 19^th Century extraction.  These are not easily available because of the very acidic nature of the mine water.

Around 1800, Morwelham on the River Tamar was the world’s largest copper port, exporting copper from Cornwall and Devon to South Wales.  Ireland has several significant copper deposits that were developed at this time.  Scotland also has sources of copper but they were a long way from the refineries.  They were not long commercial except where the copper was found with silver, as up in the Ochills outwith Stirling.  As industry developed and other sources were found abroad, almost all ores were imported.  The smelting of the ores subsequently moved nearer the sources of supply.

During the 19th century Birmingham became the main centre for fabricating non-ferrous metals in Britain, a position that is still held.  Many major developments in the copper industry emanated from the Birmingham area. 

·        In 1832 George Muntz patented a process for the manufacture of brass consisting of 60% copper and 40% zinc.

·        A method for the application of electrolysis to the refining of crude copper was invented by a Birmingham silver-plater, James Elkington, in 1864 and led to the establishment of the first such plant in Swansea in 1869. 

·        Towards the end of the 19th century Alexander Dick introduced the fundamental new process of hot extrusion for making brass rod from billet.  This was originally by the River Thames in Greenwich, London but the process wasthen rapidly developed in Birmingham and surrounding districts.

By far the greatest extension in the use of copper resulted from Michael Faraday’s discovery of electromagnetic induction in 1831 and the subsequent development of the electrical engineering industry.

The use of copper as a roofing material will continue to grow.  In many countries it is well accepted as a standard material needing only basic support structures for its low weight.  The colour of the patina developed is much appreciated and the long maintenance-free lifetime much valued.  Until recently the low lifetime cost had not been quantified, but now that authoritative figures are available it is being appreciated as much as an economic roofing material as for its looks.

Brass

Brass has been made for almost as many centuries as copper but has only in the last millennium been appreciated as an engineering alloy.  Initially, bronze was easier to make using native copper and tin and was ideal for the manufacture of utensils.  While tin was readily available for the manufacture of bronze, brass was little used except where its golden colour was required.  The Greeks knew brass as ‘oreichalcos’, a brilliant and white copper.

Several Roman writers refer to brass, calling it ‘Aurichalum’.  It was used for the production of coinage such as sesterces and many Romans also liked it especially for the production of golden coloured helmets.  They used grades containing from 11 to 28 per cent of zinc to obtain decorative colours for all types of ornamental jewellery.  For the most ornate work the metal had to be very ductile and the composition preferred was 18%, nearly that of the 80/20 gilding metal still in demand.

Before the 18th century, zinc metal could not be produced in Europe, since it melts at 420oC and boils at about 950oC, below the temperature needed to reduce zinc oxide with charcoal.  In the absence of native zinc it was necessary to make brass by mixing ground smithsonite ore (calamine) with copper and heating the mixture in a crucible.  The heat was sufficient to reduce the ore to metallic state but not melt the copper.  The vapour from the zinc permeated the copper to form brass, which could then be melted to give a uniform alloy.

Up to Elizabethan times most supplies came from Cologne (Cullen Plate) on the Rhine since there were good copper deposits in the Harz Mountains and Calamine, the zinc ore, up the Mosel River at Aachen.  Cast brass plates were poured to 3 to 5mm thickness with a composition approximately 66/34.  These were hammered and planished to give a smooth surface for engraving and enamelling on plates up to 900 x 900mm (3ft square).  Larger monuments were made by matching plates side by side with care for continuity of the artwork.  By the end of the 16^th century supplies of plate were available from Bristol.  This was thinner, and slightly softer, than imported supplies.  On occasions, some were recycled by being turned over and re-cut.

In Mediaeval times there was still no source of pure zinc.  When Swansea, in South Wales, was effectively the centre of the world’s copper industry, brass was made by direct cementation from calamine found in the Mendip hills in Somerset.

One of the principal users of brass was the woollen trade, on which prosperity depended prior to the industrial revolution.  In Shakespearean times, one company had a monopoly on the making of brass wire in England.  This caused significant quantities to be smuggled in from mainland Europe.  Later the pin trade became very important, about 15-20% of zinc was usual with low lead and tin to permit trouble-free cold working to size.  Because of its ease of manufacture, machining and corrosion resistance, brass also became the standard alloy from which were made all accurate instruments such as clocks, watches and navigational aids.  The invention by Harrison of the chronometer in 1761 depended on the use of brass for the manufacture of an accurate timekeeper that won him a prize of £20,000.  There are many examples of clocks from the 17th and 18th centuries still in good working order.

With the coming of the industrial revolution, the production of brass became even more important.  In 1738, William Champion was able to take out a patent for the production of zinc by distillation from calamine and charcoal, a process carried out in a closed, reducing atmosphere so that the zinc did not re-oxidise.  This gave great impetus to brass production in Bristol.  Incidentally, it is probable that distillation was in use in India during the 8^th-10^th centuries and also in China, well before the practice was in use in Europe.

Wire was initially produced by hand, drawing it in many stages from strips cut from plate made by ‘battery’ in stamp mills.  Although the first rolling mill in Swansea was installed at Dockwra in 1697, it was not until the mid-19th century that powerful rolling mills were generally introduced.  The Dockwra works specialised in the manufacture of brass pins, the starting stock being a plate weighing about 30kg.  This was cut in to strips, stretched on a water-powered rolling mill and given periodic inter-stage anneals until suitable for wiredrawing.

With the invention of 60/40 brass by Muntz in 1832, the higher zinc content made it possible to make cheap, hot workable brass plates.  These supplanted the use of copper for the sheathing of wooden ships to prevent biofouling and worm attack.  Muntz was one of the small number on inventors who have made good money after patenting their ideas.  His family continued the business after his death.

With improvements in water communications, the centre of the trade moved to Birmingham to be nearer to fuel supplies and to facilitate central distribution round the country.  With the invention of the extrusion press in 1894, Alexander Dick revolutionised the production of good quality cheap rods.  

Products in the House

In the kitchen are found kettles, saucepans, skillets, strainers and other tools.  The fireside is frequently the focal point of the décor of a living room and can be equipped with fire surrounds, firescreens, andirons, trivets bellows, toasting forks and ale warmers.  Much lighting equipment is made of brass whether the light comes from gas, oil, candles or electricity.  Tableware needs trays, food warmers, gongs, stands, jugs, dishes, tea and coffee pots, flatware and many other accessories from corkscrews to nutcrackers.  The home office uses paper knives, penstands, inkwells, paper weights, paper clips, letter racks, tobaccanalia and money boxes.  In the bedroom there can be brass beds, candlesticks, water cans, warming pans, toilet items, buttons, buckles, curtain rails and metal framed mirrors.  In sitting rooms can be found many types of copper and brasswares such as jardinières, bookends and decorative souvenirs and ornaments with sentimental attachments.  All round the house can be found architectural hardware including hinges, knobs, knockers, finger plates, locks, stair fittings and window furniture.  Some products have been marked by their proud makers and where available the marks have been listed.  Marks List

Design Implementation - Production Methods

Besides the influences of fashions, the design of the domestic copper and brasswares just mentioned has altered as production methods have changed and become more economical.  With care it is possible to update production methods and still maintain the qualities for which the metals are chosen so that items are still satisfying for the user.  Metal Working and Finishing

Casting has always been the most obvious way of making shaped articles and is usually an essential preliminary to subsequent forming.  Good quality sand and lost wax casting methods were well established prior to 1820.  Since then die casting in permanent moulds and continuous casting techniques have been developed to give a wider range of precision production techniques. 

Forging started as the first method of forming metal to shape.  Large reductions were not possible until heavy hot stamping hammers were powered by water mills but hand hammering was and still is used for many finishing processes such as planishing to a very pleasant appearance.

Rolling mills had been introduced during the 17^th century when they were mostly powered by water wheels.  Capabilities increased with the introduction of steam power followed by the introduction of electric motors.  This process has seen many comparatively recent improvements such as full electronic control of front and back tension on feed rolls, roll grinding and mill stressing techniques for the precision control of gauge and roll surfaces.  Finishes can now be offered to suit requirements from retention of drawing lubricants to a fully reflective mirror finish.

A stamping machine was patented in 1769 for the production of items such as coinage, buttons, buckles and similar items.  With the introduction of steam powered presses from 1789 and the use of collared dies, coining became a precision process.  Coining was developed by the Chinese and was in use in Europe by the Celts and Greeks well before Roman times.

Spinning is a craft that developed when it became possible to keep a lathe revolving in one direction rather than use a bow string to drive it in alternate directions.  After polishing, little evidence of forming marks is retained.  Deep drawing is now used to produce many straight-sided vessels. 

Wire drawing was developed in Nürnburg during the 14^th century.  Initially it was needed for the production of comb wire for preparing wool fleeces for spinning.  By 1820 it was also well established for the production of the brass chains used to suspend fittings for lighting and similar application. 

Lathe turning has long been used for the manufacture of shaped knobs and threaded fasteners.  With the introduction of NC controlled machining the economics of production have improved the competitivity of brass.  

Tube drawing was only possible in 1806 after forming and joining strip but the techniques used were very effective.  Seamless tube drawing techniques were introduced during the 19^th century, which made possible the production of long lengths of precision solid drawn tube with no risk of seam failure.  Tube Mill

Extrusion was introduced in 1894 by Alexander Dick and opened up possibilities for the design of many more products in a more adventurous way. 

Electroplating was introduced commercially in the 1830’s.  Initially this was used for plating copper alloys with a decorative silver coating but was soon used for refining copper and the production of art metalware by electrotyping.  Nickel plating was introduced in the 1870’s and chromium plating soon afterwards to provide a cheaper and more durable surface finish than silver.  From the 1930s the use of surface coatings has frequently hidden the warmth and friendliness of the underlying copper and brass products.  Where the warm copper surface is showing, some owners like it polished while others prefer it with a patina that may be either naturally formed or an applied coating. Electrotypes

Uses of Copper and Copper Alloys

Copper possesses the highest conductivity of any of the commercial metals.  Hold a piece of copper and may will feel cold, an indication of how quickly hand heat can be conducted away.   Each time you press a switch to light a room, think of the high electrical conductivity and reliability of the copper in the circuit that makes that simple operation possible.  We take for granted the electrical power and also the metal essential for its efficient arrival at our homes.  

The surface lustre and warm colour of copper and copper alloys makes them beautiful to look at and this means they find widespread use in architecture.  The attractive green surface patina enhances the appearance of copper roofing.  Bronze sculpture may have exquisite toning or patination.  Jewellery and household ornaments and fittings gleam satisfyingly.  If you look no further than your domestic surroundings, you will start to appreciate the huge role played by copper in the production of useful, attractive items that enhance our lives. 

As an assurance of long-term reliability, the word copper is used in everyday speech in the expression "a copper-bottomed guarantee" amongst others.   

The table shows some of the reasons why copper and its alloys are vital to  major types of application that depend on combinations of the great many properties available. 

Some Copper and Copper Alloy Properties and Uses 

 New, Reproduction, Fake or Original?

‘Original’ items may be hand-made by craftsmen coppersmiths and appropriately marked.  Any patina will be genuine and realistic for the age. 

 Original items may also be made largely by machine in the factories of the original designers and show the quality typically expected and a trade mark or registered design mark.  Such positive identifications are now rare in items commonly available.  Most copper and brass in Europe was not marked, though rather more in the USA.  Judging whether a piece is ‘right’ is then a matter of experience.

 ‘Fake’ is a word that is used very loosely.  Strictly it should apply only to items made to the same design and quality as the originals such that they are meant to be as good as the genuine articles.  Such good quality deserves recognition and may command a reasonable price that will depend on whether the perceived value of the original is dependant on craftsmanship and quality or age and rarity.

 ‘Reproduction’ is another very loose term.  In quality items may be as good as originals, but were or are made to a design decades or centuries after it was first produced.  Alternatively the term is sometimes used to describe items that are a pathetic shadow of the original design.  They may use much lighter gauge copper or brass, be shoddily manufactured and bear only a passing resemblance to the original style being reproduced. 

 The production of ‘reproduction’ designs is nothing new.  Most carriage clocks that are already a century old are reproductions of earlier designs.  During the 1920’s and 30’s there was a thriving market in the manufacture of goods using well tried and proven Victorian designs.  These are all collectible.  Reproduction items are described as ‘good’ or ‘poor’ or otherwise as appropriate.

 ‘Imitation’ is a term that can be taken to cover the bottom end of the reproduction market.

 During an inspection, consider some of these points:

·         Evidence of production methods used.

·         Care and pride in manufacture to give pleasure to the user.

·         Evidence of use for original purpose.

·         Patina developed through age.

·         Evidence of damage or wear through over-cleaning.

But not:

·         Analysis of the metal.

 As a broad generalisation, almost anything previously designed and made in copper or brass could then be made at any subsequent date and can still be produced today.  Manufacturing methods can be the same as those used previously or ‘improved’ using more modern equipment.  The craft skills that were used in the manufacture of the domestic items described are still available, albeit in very short supply.  Being labour-intensive, they are also expensive.  Where products have been made in quantity using machines such as lathes, presses and other forming machines, such manufacturing methods may still be valid.  A successful, good design will find a market for years, subject only to cyclical fashion trends. 

 Many manufacturers of the 1920s and 1930s were making ‘reproduction’ copper and brassware in ‘Victorian’, ‘Edwardian’, ‘Oriental’ or other styles that may, or may not, be exact copies of originals from earlier dates.  Back numbers of catalogues produced by manufacturers can give a mine of information.  As an example, between the wars, Pearson Page (later Peerage) produced a vast amount of excellent useful and decorative copper and brassware.  The catalogues of big stores, such as the Army and Navy Stores, are also being reprinted occasionally and are very useful. 

 The cost of making something using craftsmanship can be much higher than the use of modern mass production equipment.  The results are by no means the same.  The work of the craftsman is evident when copperware is examined.  Similar products made by cheaper techniques generally lack the obvious quality and evidence of care in manufacture.  Their quality may be good but each item is substantially identical to every other one coming from the production equipment.

 When something has been wrought by a coppersmith, it will usually not sound ‘tinny’ when tapped by a finger nail.  This is because the coppersmith has to work the metal in a soft condition and soft copper does not resonate.  Even after finishing with a planishing hammer to increase hardness, copper does not become as hard as some currently produced.  New items are generally produced from thinner, hard rolled, copper or brass.  This is lighter and hence cheaper than thicker metal and also harder and stronger.  Hard copper and brass does resonate and will give a recognisably ‘tinny’ answer to your finger ‘ping’. 

 Surface marks may show on items made from sheet, being left after production methods.  Modern rolling mills produce sheet that is uniform and free of blemishes.  The equipment displaced by the new mills is frequently sold second-hand to small enterprises anywhere in the world, so evidence of rolling defects is no guarantee of age.  Marks left by spinning or drawing dies can also be evident and are evidence of rapid, cheap production with insufficient finishing and quality control.  Surface Finishing

 A patinated finish can come out of a bottle buy just like the dyes used for human hair the effects can be equally as good or as disastrous.  Statues are always carefully patinated before leaving the foundry, this being a costly, lengthy process.  Modern cheap production items, for example tankards or sundials, can easily be patinated before leaving the factory but the results, although usually decorative, are difficult to make to resemble the effect of years of ageing of unpolished copper or brass.  Patina Finishes

 Evidence of use can be important for most of the items described were not originally made as decorative ornaments.  Most domestic copper and brass will have been cleaned regularly during years of use, and may have lost some original surface features.  During a lifetime in service, some hard knocks may have been taken and the effects will show.  With the mortar and pestle this would have been intentional.  If a purchase does not look as though it has just come out of the showroom and is even looking somewhat the worse for wear, then enjoy thinking of the useful life that it has had so far.  Since much copper and brassware is now bought only for its good looks, restoration is often welcome and items that look well cared for can command better prices.

 Castings can be difficult to date if as much care has been taken in making reproductions as was for the original.  However, effective fettling of castings is expensive, as is the hand chasing in of fine detail.  Cheaply finished castings, of whatever age, will show evidence of mould joint lines, pouring runner connections and heavy-handed polishing.  If castings have been made using an original as pattern, fine detail is likely to have been lost.  Because of solidification shrinkage, the casting will also be slightly smaller than the original though this may not be easily obvious.  Casting Fabrication

Analysis of Composition

Many papers have been published on the production techniques used from the copper age through to medieval times and the compositions of the alloys typical of many areas and epochs.  There is no difficulty in taking small samples of swarf from drillings and getting them analysed for both alloying additions and impurities.  However, the cost is significant and the results generally inconclusive for most of the types of objects discussed in this book. 

 Since copper is now refined by similar methods in most countries the purity produced can be routinely very good and is typical only of the quality control methods used.  There are only a few exceptions where copper ores from some mines contain unusual trace elements that persist detectably through refining.  Copper and brass have been traded round the world for centuries and recycling has been an essential part of the copper economy since long before the scrapping of such wonders as the Colossus of Rhodes or the Panthenon roof.  With a few exceptions, copper and brass products of the types described can be made from metals that are a mixture of new and recycled materials from many sources.  It is therefore very difficult to relate a metal composition to a given area or epoch.

 Dating Copper and Brass

It is generally difficult to absolutely sure of the date of manufacture of any particular object.  Unlike the systems in compulsory use for silver and gold, there was no requirement to hallmark copper or brass.  Early products made by members of the Worshipful Company of Braziers, (latterly the Worshipful Company of Armourers and Braziers) do frequently carry a makers mark.  Many of these and others have been described by Hornsby (see References).

 In the 20^th century, some products were made with the manufacturers’ identity clearly and proudly displayed.  However, even some of the best products are incognito, perhaps to avoid confusion when they were marketed in different ways by a variety of big name stores.  Some coppersmiths have marked their work, the majority have not.  Other marks present can be those of the original or subsequent owners.  Where relevant, comments are made throughout this book.

Period

Descriptions of items frequently refer to a period.  This may indicate the age range during which it had been made or just describe the design of the piece as typical of those current during the period.  A table gives a guide to the timescales most likely to be encountered.  Design Developments

Guide to Timescales

If a period description is used on an item it should mean that it was made during that time.  However, it can also be used more loosely to describe a design style for something actually made later.  Look for the word ‘style’ in a period description.  Many styles were in vogue or revived during these periods.  Design Developments

Diamond (or Kite) Registration Mark

From 1842 there was a system of registering design introduced with the aim of giving at least three years’ protection for product designs.  The objects showed a diamond mark that classified the product and identified the registration year, though the product itself may have been made later.  The use of the old ‘Kite Mark’ term should not now be confused with the British Standards Institute mark of assurance of conformance to specification now common on many domestic products.  The first series, from 1842 to 1867 had a letter identifying the year at the top of the diamond.  A second series, from 1868 to 1883 had the year letter in the right hand quarter of the diamond.  Even though these marks were introduced to cover items in quantity production, few products now available show them.   Registered Designs

Registered Design Numbers

The system of registering designs with a specific number was introduced at the end of 1883.  Where used, such Registered numbers (Rd No.........) give an accurate date for when a design was first produced.  Such designs could then be produced in quantity for as long as needed or fashionable and numbers therefore only give the earliest date in which an object could have been produced.  Since improvements in design have always been a driving force in the industrial societies, many of the numbers would only have been used for a few years and therefore do give a helpful guide.  They are found on many commonly seen domestic items, especially pieces that were meant to be both decorative and useful.  Nominally utilitarian products such as kettles and pans rarely show the numbers unless incorporating an unusual design feature such as those boosting efficiency.  Registered Designs

Special Topics