São Julião da Barra Pewter

Four of the 27 areas identified in São Julião da Barra as having relevant archaeological interest have yielded cultural materials dating from the late 16th and early 17th centuries, presumably resulting from the shipwreck of the Portuguese Indiaman Nossa Senhora dos Mártires, which was lost against the fortress on September 15 1606. In three of these four areas pewter artifacts have been found.

ShipLab Report - S. Julião da Barra Pewter

 


 

 

 

Introduction

The earliest pewter pieces in the archaeological record date from the Roman period - from the 3rd century onwards - and amount to only a few hundred in number. It is not known how pewter was utilized through the early Middle Ages, except for some chalices and patens found at Metz, France, in priests' tombs dating from the 11th and 12th centuries.

It is thought that pewter may have been used in poor churches as a substitute of silver for the liturgical tools. Anyway, its production developed during this period and by the 13th century the production of pewter utensils was a well organized craft in France. In the 14th century its production was regulated in England, suggesting that also there it was a developing craft.

During the 15th and 16th centuries, as the houses of the growing middle classes became more comfortable and domestic life more pleasant, pewter became a suitable material for daily use. First used mainly for kitchen utensils, it soon became a widely used material, replacing wood and coarse pottery in the fabrication of dishes, trays, measures, flagons, jugs, tankards, and mugs, but also of spoons, candlesticks, boxes, and other household utensils.

In the 16th and 17th centuries it became decorated with cast motifs, particularly on the lids and handles of tankards; in Germany, Switzerland, and Scandinavia incised decoration and undulating lines made with a wheel became fairly popular.

Although many metalic alloys do not survive well in marine environments, pewter performs quite well. Even after several centuries on the sea, both pewterer marks and possession marks are frequently preserved on the surface of pewter ware. This is the case of the large pewter collection of 269 artifacts recovered from the sunken ruins of Port Royal by treasure hunter Robert Marx in the 1960s and by a team from Texas A&M University and the Institute of Nautical Archaeology during the 1980s. Besides 155 pieces of flatware this collection includes hollowware, spoons, kitchen utensils, and other artifacts.

Corrosion on marine environments depends greatly on the alkalinity or acidity of the medium surrounding the artifact. The quality of the alloy - in terms of the percentages of the several metals mixed to obtain a certain type of pewter - and the quality of the mixture can influence the corrosion process. Surfaces can present small eruptions or uneven holes, as a result of different rates of corrosion of the metals that form the alloy.

Pewter is not frequently found in terrestrial sites.

Candle holders (Photo: Pedro Gonçalves, CNANS).

On one hand it does not preserve well in contact with most soils in the presence of moisture, and on the other hand pewter objects were generally not discarded because they had a long durability and a fairly high value when sold for recasting.

Nevertheless, pewter ware is by no means rare. Many museums and private collections have large assemblages of pewter ware, unfortunately many times collected piece by piece, frequently without a cultural provenience, almost always acquired from auctions, particulars, and antique shops.

Stack of pewter plates and saucers found in the SJB1 area (Photo: CNANS)

A long list of artifacts can be made with pewter. Museum and private collections frequently include trays, plates, cups, tankards, porringers, bowls, bottles, bottle caps boxes, all sorts of kitchen utensils - such as ladles, funnels, and colanders - but also common house objects like chamber pots, urinals, candlesticks, and oil lamps, picture frames, decorative figures, watch cases, sundials, inkstands and sand casters. Other artifact types include tokens, buttons, buckles, badges, rings, chains, as well as toys, medical instruments, or ecclesiastical wares and religious implements.


 

 

 

Pewter

Pewter is an alloy of tin and lead used at least since the Greek times. When it is new it presents a beautiful silver color, turning darker as it ages and becoming gray with a lustrous shine.

Most items existing today were cast in heavy bronze moulds, sometimes in several pieces that were later soldered together. The composition of the alloys varied according to the items to be manufactured, going from less than 1% to up to 40% of lead. Other metals were added to the alloy, such as copper, zinc, or antimony, these last two utilized only towards the end of the 17th century. When more lead is used in the alloy the mixture is more malleable, and it is easier cast difficult shapes. On the other hand, the smaller the amount of lead used, the stronger and sturdier the resulting alloy is.

Alloys with high contents of lead - up to 40% - were known as "black metal" and generally used in non food-related items, a good practice in view of its very poisonous nature. Alloys with 23 to 30% of lead (and 1 to 2% of copper) were known as "lay metal" and used to cast most hollowware, such as measures, beakers, and candlesticks. Much sturdier was the "trifle metal", a mixture with more or less 10% of lead, used to cast tankards, pots, buttons, buckles, candle moulds, and toys. Finally, "fine pewter" was used to make "solid-ware" or "sadware", the flat and easy to cast flatware to which more strength was demanded. It was a mixture with less than 1% of lead and 1 to 3 % of copper, sometimes hammered after being casted - and before being finished at the lathe - to increase its density.

Tin

Tin was already found in ancient Egyptian tombs, by then considered just a different form of lead. Known to the Greeks, who called the British Isles Cassiterides, tin was widely exported from Cornwall to the rest of Europe during the Roman period.

Tin is a metallic element (symbol Sn), highly ductile and malleable at a temperature of 100° C (212° F). It melts at about 232° C (about 450° F), boils at about 2260° C (about 4100° F), and has a specific gravity of 7.28. Tin's atomic number is 50 and its atomic weight is 118.69. The principal ore of tin is the mineral cassiterite (SnO2) found in Cornwall, England and Germany, but also in the Malay Peninsula, Bolivia, Brazil, Australia, and Alaska. Tin ranks 49th in abundance of the elements in the earth's crust.

Lead

Lead is an exceptionally soft metal and thus very easy to work. It was one of the first known metals, used by the Egyptians, already mentioned in the Old Testament, and utilized by the Romans in many trades, from the making of water pipes, soldered with an alloy of lead and tin, to the casting of statuettes and sounding leads for nautical use.

Lead is a metallic element (symbol Pb), very dense, soft, malleable, and ductile. When gently heated it can be forced through annular holes, making it very easy to cast objects. Lead melts at 328° C (662° F), boils at 1740° C (3164° F), and has a specific gravity of 11.34. Its atomic number is 82 and its atomic weight is 207.20. Lead occurs naturally in eight isotopic forms, of which four are stable and four radioactive. The ore of lead is widely distributed all over the world in the form of a sulfide called galena. It ranks 36th in natural abundance among elements in the earth's crust. As a raw material lead presents a major drawback: it is highly poisonous.


 

 

 

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