Działalność krakowskiej Wielkiej Wagi w kontekście badań metaloznawczych

THE FUNCTION OF THE GREAT SCALES IN KRAKOW IN THE CONTEXT OF METAL SCIENCE The basis for the economic development of Kraków in the Middle Ages was the city’s involvement in wide-ranging trade in metals. Back in the 13th century Kraków was a key player in the sale of Slovakian copper. The main route of exporting that metal passed through the city, from where it was dispatched to Gdańsk and further by sea to the countries in Western Europe. The merchants of Kraków monopolized the trade in that precious metal for more than 300 years. They also controlled the sale of Polish lead, exported from the deposits located between Silesia and Kraków via the lead sale centre in the city to Hungary, Bohemia and Germany. Kraków owed its position in the transit trade to a convenient location at the intersection of trading routes and the privileges received from rulers. The right to store copper was granted to Kraków in 1306, and the corresponding right with regard to other metals was bestowed upon it before 1335. By his privilege of 1358, King Casimir III the Great confirmed the right of Kraków to have two scales, one of them being used to weigh metals. The existence of such a device in the city back in the 13th century was confi rmed during the archaeological survey carried out in Main Market Square (Rynek Główny) in Kraków in the years 2005–2006. Originally located in a wooden structure, the scales were housed by a stone and brick building since the middle of the 14th century. Metals were not only weighed, but also traded in at the Great Scales. The latter activity was evidenced by the historical metal items unearthed during the excavations. Apart from the unique discovery of a huge loaf of lead and an undamaged slice of copper, the finds at the site of the Great Scales included sections of copper, iron and lead slices, and a range of smaller fragments pointing to the practice of dividing pieces of metal intended for retailing. The excavation works also revealed many pieces of metals pointing to the pursuit of production activities at the Great Scales. As was confi rmed by metallographic tests, these activities had most probably been aimed at obtaining silver, and they had been connected with the silver melting shop situated in the western part of the building. The largest amounts of the said postproduction scrap metals were found in the deposits dating back to the 15th and the 16th centuries. It was during that period that the process of extracting silver from copper by way of melting the latter with lead became widely popular across Europe. The new method was brought to Kraków by Jan Thurzo in the second half of the 15th century. It can be assumed that it was applied during the production activities the traces of which were discovered at the site of the former building of the Great Scales. Further research in the area of metal science will defi nitely contribute to gathering more knowledge on that matter.