Journal of Archaeology in the Low Countries 4-1 (October 2012)Thijs Maarleveld; Alice Overmeer: Aanloop Molengat – Maritime archaeology and intermediate trade during the Thirty Years’ War1

3.4 Tin in rolls, packed in barrels

At the southeastern end, a tier of spruce barrels was stacked on top of the wrought-iron bars. These barrels had broken up and their contents had been dispersed, but their bases and some of their contents were still found in their original position at the top of the wreck mound (fig. 21). The barrels contained tin in a typical form of roughly cast sheets, rolled in a rough cylinder, approximately 40 cm long (fig. 22). The weight of the rolls varies considerably and is 4.727 kg on average. Some rolls are preserved in excellent condition, others have decayed and eroded. In total 1514 kg of tin has been excavated, deriving from a minimum number of 359 rolls. An interesting bonus is a few pieces that can be interpreted as quality samples (fig. 23) rather than ordinary production (cf. Reinheckel 2002, 29). The total weight of the shipment, including barrels, must have been at least two tons.

The sheets generally have three marks, applied with a die in a molten appliqué. Twenty-four different dies have been identified (HyperlinkTerhorst). The images include a range of heraldic symbols, years, monograms and words in German, for instance: ‘SEIFFEN*ZIN*VON*DER*PLATEN’. In 1988, the general provenance and probable quality (‘Drei-Zeichen-Zinn’) was established with the help of the Sektion Bergbauforschung des Kulturbundes der DDR, Ortsgruppe Seiffen. ‘Seiffen’ does not refer to the town in Saxony, but ‘Platen’ refers to Horní Blatná on the southern flank of the Erzgebirge/Krušné Hory (Ore Mountains), in the present-day Czech Republic, which was called ‘Platten’ under Bohemian rule. Vítězslav Bartoš (1994), a local historian from the city of Karlovy Vary, correlated the marks with individual mines. Besides the mines of Platten/Horní Blatná, these include the mines of nearby Seifen/Rýžovna, Hengst(er)erben/Hřebečná and Gottesgab/Boží Dar. A smaller portion derives from Eibenstock in Saxony on the northern flank of the Erzgebirge. As five more dies have been recognised since 1994, some tin may derive from other locations that have not been identified.

In the Erzgebirge, tin ore (cassiterite) was primarily extracted from Seifen, a term that refers to alluvial placer deposits (fig. 24). Water was used extensively to sort and rinse the ore. It is the simplest method of extraction and produces the purest ore. Subsurface mining only took place once alluvial deposits were exhausted (Hedges 1964, 13). Operations in the Erzgebirge are extensively and analytically described by Georgius Agricola (1556) (fig. 25), who lived in Annaberg in Saxony and had first-hand knowledge of the works. He does not specifically refer to Horní Blatná, but mentions nearby Joachimsthal/Jachymow. Tin from contaminated ore was usually cast in bun ingots that could be smelted for further refining. This was unnecessary for Seifenzinn: . . . ‘if the metal is pure, it is poured immediately upon thick copper plates, at first in straight lines and then transversely over these to make a lattice’ (Agricola 1556, book IX; transl. Hoover & Hoover 1950, 414). An experienced smelter could separate any contaminations immediately and the quality was tested visually while pouring (pers.comm. Dr Christoph Bartels, 2011). Unrolled sheets from Aanloop Molengat reflect the lattice pattern that Agricola describes (fig. 26). After a sheet was rolled with a wooden mallet, each roll was impressed with an iron die. According to Agricola, low-quality tin had one mark, while Seifenzinn had two. The rolls from Eibenstock reflect this. The rolls from the Bohemian production centres all have three marks: two regional denominations, patented by the crown,^[6] and a producer’s mark (HyperlinkComb). Although the third mark was probably introduced to suggest even better quality, and although that suggestion is attractive to Bartoš (1994, 2), analysis with XRF shows a tin content of more than 99% for Bohemian and Saxon products alike (HyperlinkXRF). This high quality means that the metal could be used for many alloys and purposes, including high-quality cannon bronze and pewter finewares (Kellenbenz 1987; Dubbe 1978).

The stamps feature dates in the range from 1556 to 1630. Evidently they refer to the dates when the patent was established or the trading and production house was founded and the die was made. It is likely that the tin was produced shortly after 1630. As a result of the Thirty Years’ War (1618-1648), production in the area had fallen considerably, but Aanloop Molengat shows that it still had its share of the international market (Kellenbenz 1987). Despite the war that profoundly affected the region in those years, it is likely that the tin was collected in the staples of Nuremberg or Leipzig, where the important entrepreneurs in the German tin trade were established. Prices had risen steeply in response to armament demand (Bartoš 1994). The Peace of Prague (30 May 1635) may have been a good occasion to resume trade, but the Main-Rhine route through to Amsterdam was frequently blocked and continued to be impeded after the blockades of 1634-1635 (Haller von Hallerstein 1975, 63; Israel 1980, 473-475). It is therefore likely that the Elbe route through Hamburg was followed. The fact that this route was not uncommon is illustrated by a decree of 1613 establishing the wages of skippers transporting ‘tin in barrels’ from Hamburg to Amsterdam (van Dillen 1929, 44-47). A source relating to a dispute on tin quality involving Leiden tinsmiths refers to Hengst(erben) as one of the sources of tin in rolls (Anon. 1592). At what point en route the rolls were packed in barrels is unclear. It cannot have been at the site of production. Several assemblages of rolls were found in close association, either with the remains of their barrel or cemented together. Not all rolls in these assemblages had the same marks. They must have been packed at a middleman’s or conveyor’s entrepôt. With 70 to 90 rolls in each barrel, we are dealing with a shipment of four, five or six barrels in total.

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