Daniel Berger
I am a researcher at the Curt-Engelhorn-Zentrumr Archaeometrie in Mannheim. My research interests encompass the analysis of archaeological materials, their manufacturing processes, and the reconstruction of historical trade routes. I utilise scientific methods such as isotopic analysis, chemical analysis, material characterisation, and experimental archaeology to uncover the history of objects, technologies, and materials. My current focus is on determining the provenance of metals (tin, copper, and others) to understand the cultural and economic connections of past civilisations and the spread of metallurgical innovations. Previously, I have investigated ancient metallurgical techniques such as patination, plating and inlaying, pewter casting, and metallurgical and technological aspects of post-medieval book printing. I am open to exploring any aspect of metallurgy, ranging from its beginnings to the post-medieval era.
Address: D6,3
D-68159 Mannheim
Germany
Address: D6,3
D-68159 Mannheim
Germany
less
Related Authors
InterestsView All (45)
Uploads
Books by Daniel Berger
The find of casting moulds belonged to a workshop that was situated in the backyard of a townhouse plot on the old road »Goldschmiedebrücke« (today the northern end of Regierungsstraße) between Magdeburg’s cathedral precinct and the civil town. The property was located only three house numbers away from the former goldsmith’s guild and was demonstrably used from 1284 onwards for church construction purposes. This precise date is thus a terminus ante quem, because the workshop that had probably been in operation since the 11th century had to be removed for this purpose. Despite several ground-level furnace plates of burnt loess and other features, it was not ascertainable whether the workshop had been used for casting the entire time. The furnaces were repeatedly renewed during the long operating period, which resulted in the floor level being raised by more than 1.5 m. In addition to the furnace structures, rectangular borrow pits and pits with wooden bracing had been set up, reaching down into the loess soil almost as far as 2 m. Remains of two pithouses originate from the early period of the recorded area and date before the commissioning of the workshop. Here, remains of bone carvings and pigments were discovered. The casting moulds themselves were found in a rubbish pit specially set up for their disposal at the time of the abandonment of the workshop. Since not all pieces were located in the pit, it can be assumed that originally more rubbish pits existed, which however remained undocumented due to the rather small excavation area.
The moulds were sampled for petrographic analyses and consist of fine-crystalline limestone that was presumably mined in the northern Harz foreland near the town of Thale. Due to its low heat resistance, this particular type of limestone was not suitable for casting non-ferrous or precious metals; however, it was proven by extensive casting experiments that it could be used for casting pewter and lead. By casting pewter and lead, it was possible to use the moulds several, if not countless times, since they were designed as permanent moulds. At the same time they are products of serial manufacturing: Apparently, standardised raw moulds with even mating surfaces were delivered to Magdeburg and used for certain motifs or groups of motifs depending on size, thickness, and shape. Apart from flat moulds, there are also a number of vaulted exemplars for casting objects of a more sculptural shape, like miniature figures and vessels. Moreover, many of these finds have been worked on both sides and could thus be used alternately for the sequential manu-facturing of objects. Stacking moulds for rationalisation, as they are known in England, are however not represented. Quite a number of pieces show nothing but engraved preliminary drawings or fragmentary motifs, which indicates that these were the back parts of multi-piece casting moulds that did not have to be worked in such great detail. In addition to fine cutting tools divider calipers, engraving needles, various kinds of drills (e.g. spoon or spotting drills), milling tools as well as a lathe were standardly used. The fine-grained rock material of the limestone allowed for a highly precise and detailed cutting of the motifs’ mould cavities, which resulted in very complex and elaborately designed objects.
The casting moulds were mainly constructed from two or three components; however, there are several finds that consisted of four, five, or even eight parts. To ensure the accuracy of fit, holes were drilled in the mating surfaces of each matching moulding which then took up tin-lead dowel pins. For a secure fixation additional wires or bandages had to be wrapped around the moulds.
The casting material was poured through a sprue into the assembled moulds and runners or feed sprues led the material directly into one or multiple cavities. In this manner a large number of objects were serially mass-produced. Engraved vent holes or – in the case of complex objects – internally drilled vent channels, which were connected to the mating surfaces, facilitated the escape of air or gases trapped in the mould cavities. The Magdeburg foundry documents the earliest evidence of this venting technology so far, which was then apparently adapted by other foundries across the whole of Europe.
Apart from two moulds for a pilgrim’s amulet and a badge depicting the Crucifixion, motifs of profane nature predominate in the find material. It can thus be assumed that the foundry produced items for common bourgeois households. The range of motifs is extremely extensive and can be divided into following subject groups:
1. Small- and large-sized fibulae or brooches
2. Decorative fittings and mounts
3. Belt and strap buckles
4. Rings
5. Pendants
6. Buttons and beads
7. Toiletry (e. g. mirror cases)
8. Toys (miniature vessels and figures)
9. Spoons and bowls/plates1o. Chapes for the scabbards of knives or daggers
11. Micro scale or candlestick components
12. Box hardware and fittings
13. Miniature hatchets
14. Religious themes
There is a large variety of shapes within the individual groups, especially with the numerically predominant fibulae/brooches and fittings that together make up a total of c. 60 % of all moulds. The remarkably extensive range of motifs, which presumably was even larger originally, demonstrates that in the 13th century almost everything was cast, which was technically feasible and according to the customers’ desires. In doing so, there seem to have been hardly any technical difficulties, since it was possible to even produce the most complicated and sculptural objects by means of chill casting. Here, one was able to draw on long established and well practised techniques like full-mould and core casting, but more rarely used technologies like slush casting were also mastered. What is furthermore notable is that a lathe was used for creating and developing individual motifs (e. g. scale pans).
Of particular importance is the detected casting material, since it enables statements on a commercial orientation of the workshop. Besides a large number of dowel pins, corroded relics of tin-lead metal were also found in the casting cavities or sprues of several mouldings. In addition to this, a particularly high amount of residues was found in the vent channels, where the metal was pressed in during the casting process. Here, too, scientific analyses have revealed alloys of lead and tin, which were occasionally admixed with a little copper for an increase in hardness. In view of this fact it can be assumed that the entire find complex is associated with pewter casting and previously belonged to a tin foundry. This would thus be the earliest evidence of a presumably independent tin moulder. Even if the workshop produced tin objects (or white metal in general) it is still highly likely that many objects, especially the most elaborate and decorative ones, were modelled after precious metal realia. This is indicated among others by the reper¬toire in itself, but also for example by the imitated granulation works, filigrees, and gems at the finds, and the location of the foundry in a district otherwise charaterised by gold- and silversmithing. It may be suggested that all these workshops were part of some kind of pre-industrial production and trading system of a larger scale, which was made pos-sible by or required a correspondingly large urban market like the one in Magdeburg. This means that we are looking at an exclusively commercially oriented craft, which emerged in a completely different environment than the monastic goldsmithery described by Theophilus Presbyter in the early 12th century. In contrast to a serial and profane mass production, the monastic smithery focused on the manufacturing of elaborate and individual objets d’art for ecclesiastical demands. In this context, the above mentioned cast objects contribute to a change of our point of view regarding day-to-day life in the 13th century by means of their quantity as well as their professional, serial standardisation and compilation within a time horizon before 1280. They indicate a much richer everyday material cul¬ture in the urban milieu than was sometimes suspected. At the same time the Magdeburg foundry with its mass production both for a regional and presumably for a supra-regional market, marks an important step in the history of the development of the town and towards the guild-dominated trade structures of the late Middle Ages. Without doubt, this find of casting moulds thus represents a »treasure trove« in various aspects.
Die beiden hier vorzustellenden, zahlenmäßig dagegen eher bescheidenen Letternfunde vom Gelände des ehemaligen Franziskanerklosters übertreffen die Massenfunde an Bedeutung noch einmal beträchtlich, zumal nicht nur eine Zuordnung zu einer sehr früh und erfolgreich produzierenden Wittenberger Offizin möglich erscheint, sondern gleichzeitig auch bislang einmalige Notentypen gefunden wurden. Im Folgenden sollen zunächst die Fundstelle und die Fundumstände beleuchtet werden, bevor die Lettern selbst, insbesondere hinsichtlich ihrer Typometrie, Typografie und Metallurgie, behandelt werden. Aus den aufgefundenen Typen ergibt sich schließlich die Frage nach der historischen Zuweisung des archäologisch geborgenen Materials, zu deren Klärung alle verfügbaren Informationen zusammengetragen werden. Den Abschluss der Arbeit bilden musiktheoretische Betrachtungen sowie einige Bemerkungen zur Musikgeschichte der Reformationszeit, die gerade durch das Wittenberger Themenjahr 2012 »Reformation und Musik« (Abb. 2) im Vorfeld des 500. Reformationsjubiläums 2017 und eine musikgeschichtliche Ausstellung 2012 in den Franckeschen Stiftungen in Halle (Saale) besondere Aktualität besitzen."
and patination technique which are archaeometallurgically
treated within the framework of the Bronze Age
north of the Alps. The aspect of patination is here perceived
as a pure artificial procedure. On the one hand the investigation
should reveal how damascenings were realized on
bronze objects and if the observations provide evidence for
clarifying the provenance of the rarely used inlay technique
– a major question that is still unsolved. On the other hand
authentic methods are to be examined in detail that once
presumably allowed the patination of prehistoric damascened
items for enhancing the weak color contrasts between
base metals and inlays.
First of all the study shows that metal inserts were not
used frequently throughout the whole Bronze Age and in
the different areas north of the Alps. There were longer
gaps between the various stages of the era. In contrast platings
as a special form of damascening (»surface damascening
«) were applied continuously since period Montelius
II, yet this decoration is only a characteristic feature for the
Nordic circle that was not adopted in southern regions.
Using only electron as decoration metal throughout the
entire Bronze Age platings differ from damascenings with
metal inlays (»inlaid damascening«) in another point that
besides gold or electron they mainly availed of unalloyed
copper. Later the spectrum of inlaid damascenings was
enlarged by pewter, bronze, and iron. The investigation
demonstrates furthermore that the cavities for inlays on
most objects were already designed prior casting. However,
multiple evidence is found for reworking cast grooves. Only
in some cases the grooves were made exclusively by chasing
or engraving.
For Late Bronze Age artifacts it becomes clear on account
of stylistic and technical characteristics that the metal inlay
technique was practiced only by few workshops, nevertheless
probably having influenced each other. Such considerations
are much more difficult to proof for the Early and
Middle Bronze Age as there are less damascened pieces. Yet,
similar decoration patterns and techniques suggest interactions
between single craftsmen or workshops. Unfortunately,
the provenance of the damascene technique still
remains unclear despite this new investigation. Though, it
is at least unlikely that the polychrome decoration was
directly adopted from Mediterranean or even Greek prototypes,
but the stimulations rather have to be searched in the
Carpathian region. Finally, also a selfcontained development
somewhere in Central or Northern Europe cannot be
completely ruled out.
On the basis of patination experiments it can be shown
that in fact human urine is suitable for coloration of damascened
objects with copper inlays. Ideally, the medium produces
purple-black patinas on unalloyed copper while the
addition of elements such as tin or arsenic to copper gives
somewhat lighter appearances. High concentrations of tin
result in light yellow or slightly green-gray coatings. Even
these colors may have been desired in prehistory on tin
bronzes as they perfectly contrast with purple-blackish
patinated copper inlays. The investigated method therefore
emerges as a possible and formerly neglected way for patinating
many damascenings of the Bronze Age north of the
Alps. For this, however, some preconditions have to be fulfilled
which are discussed in detail in the following work.
The petrographical examination of thin sections from 15 stone samples with transmitted- and direct-light microscopy and the examination of rock powders has shown the use of a fine-grained Jurassic and/or Cretaceous marly limestone. For it the so called »Plänerkalkstein« of the northern foothills of the Harz Mountains is most probable. But also the »Solnhofener limestone« of the southern part of the Franconian Jura has to be considered.
Because there are no discolorations within the pouring system of all moulds it is clear that they cannot have served for the founding of bronze, gold and silver, which is confirmed by the results of the casting experiments. With energy dispersive X-Ray fluorescence analysis, light and scanning electron microscopy it could be shown reliably that 23 metal specimens of the cast system and several registration holes were made of pewter. Sometimes small amounts of copper might have been added to these tin-lead alloys. Because metal residues were available in the cast system at only six moulds, you cannot conclude on the general use of these metals for all of the 500 moulds. With discolorations outside the cast system and bright, powder like coatings on the complete surface at 60 % of all moulds an indirect reference to their use is given. Both observations indicate a heating of the whole mould. This is reinforced by scanning electron microscopic examination of thin sections and diffraction analysis of powder samples which revealed the »burned« character of the coating. Glowing tests with the Plänerkalkstein and Solnhofener limestone demonstrated that discolorations arise from 300 °C upwards, however, decomposition of calcium carbonate starts at around 700 °C. Thus all moulds with a bright surface coating must have been heated at temperatures of at least 700 °C. Such a measure can only be explained plausibly in connection with the metal cast and furthermore with the casting of pewter under consideration of the missing discolorations in the cast system. According to the results of the casting experiments it is quite improbable that the moulds had been heated at high temperatures like 700 °C before their use. However, a general explanation for the motives of a possible heating after founding cannot be given with the performed examinations. So some questions are still unanswered."
Papers by Daniel Berger
The collection of the Landesmuseum Natur und Mensch in Oldenburg contains seven blades of the Sögel-Wohlde types, which are discussed within the framework of an ongoing research project 'Origin, development and technology of the Bronze Age blades of the Sögel-Wohlde-district'. The aim of the project is to study the cultural and material relationships between the Nordic Circle and potential regions of influence such as the Carpathian Basin and the Northern Alpine region. The finds from Oldenburg, which predominantly consist of Sögel-type blades, form part of the story and are studied to correlate archaeological information such as typology, shape, find location including archaeometric data such as chemistry and isotopic signatures of lead, copper and tin. Even though Sögel-type blades were the most common finds around Oldenburg, they were far from uniform based on a large variation in design and decorations. Similar motifs of incised lines, dots and garlands continuously appear yet in different configurations. This suggests that there were no strict cultural norms that allowed for the fluid adaptation of both Nordic and foreign design elements that may have originated in the Carpathian Basin. Archaeometrically however, the blades are very uniform consisting of chalcopyrite copper containing nickel and arsenic as trace elements, suggesting the use of similar copper deposits that may have come from only a limited number of copper suppliers. However, future isotopic studies are required to make further statements which will provide further insights into the material and cultural interdependencies of the Sögel-Wohlde district.
Der Stellenwert des Magdeburger Komplexes ist aber nicht allein an seiner immensen Fülle zu bemessen. Große Bedeutung besitzt der Fund von steinernen Dauerformen v. a., weil er auf gießereitechnischer und metallurgischer Seite eine Reihe neuer, bisher ungeahnter Einblicke in das hochmittelalterliche Gießereiwesen erlaubt. Außerdem ist die potenzielle Verwendung der Gießformen zur Herstellung von Zinnobjekten bemerkenswert, die in dieser Intensität einmalig wäre und die mittelalterliche Handwerkskultur der Zinngießer – nicht nur derjenigen in Magdeburg – in einem völlig neuen Licht erscheinen lassen würde.
Im Gegensatz zum vorangegangenen Kapitel stehen im Folgenden vorwiegend die gießtechnischen und archäometallurgischen Aspekte der Gießformen im Vordergrund. Dafür war es nicht nur möglich, die Formen eingehend mikroskopisch hinsichtlich der Gesteinsart und auf Gebrauchsspuren hin zu prüfen, sondern auch Metallreste und Gesteinsproben von zahlreichen Exemplaren mit naturwissenschaftlichen Analyseverfahren zu untersuchen. Darüber hinaus wurden Gießversuche mit Vergleichsgestein in die Betrachtungen einbezogen. Diese spezielle Kombination erlaubt es, ein bisher beispielloses, konkretes Verständnis von der Funktion und Geschichte der Gießformen zu erhalten. Bevor jedoch auf die Ergebnisse der naturwissenschaftlichen Untersuchungen eingegangen wird, werden in Ergänzung zu den Darlegungen von G. Ditmar-Trauth (siehe Kap. Der Magdeburger Gießformenfund) zunächst noch einmal technische Kriterien herausgestellt und vertiefend erläutert.
The find of casting moulds belonged to a workshop that was situated in the backyard of a townhouse plot on the old road »Goldschmiedebrücke« (today the northern end of Regierungsstraße) between Magdeburg’s cathedral precinct and the civil town. The property was located only three house numbers away from the former goldsmith’s guild and was demonstrably used from 1284 onwards for church construction purposes. This precise date is thus a terminus ante quem, because the workshop that had probably been in operation since the 11th century had to be removed for this purpose. Despite several ground-level furnace plates of burnt loess and other features, it was not ascertainable whether the workshop had been used for casting the entire time. The furnaces were repeatedly renewed during the long operating period, which resulted in the floor level being raised by more than 1.5 m. In addition to the furnace structures, rectangular borrow pits and pits with wooden bracing had been set up, reaching down into the loess soil almost as far as 2 m. Remains of two pithouses originate from the early period of the recorded area and date before the commissioning of the workshop. Here, remains of bone carvings and pigments were discovered. The casting moulds themselves were found in a rubbish pit specially set up for their disposal at the time of the abandonment of the workshop. Since not all pieces were located in the pit, it can be assumed that originally more rubbish pits existed, which however remained undocumented due to the rather small excavation area.
The moulds were sampled for petrographic analyses and consist of fine-crystalline limestone that was presumably mined in the northern Harz foreland near the town of Thale. Due to its low heat resistance, this particular type of limestone was not suitable for casting non-ferrous or precious metals; however, it was proven by extensive casting experiments that it could be used for casting pewter and lead. By casting pewter and lead, it was possible to use the moulds several, if not countless times, since they were designed as permanent moulds. At the same time they are products of serial manufacturing: Apparently, standardised raw moulds with even mating surfaces were delivered to Magdeburg and used for certain motifs or groups of motifs depending on size, thickness, and shape. Apart from flat moulds, there are also a number of vaulted exemplars for casting objects of a more sculptural shape, like miniature figures and vessels. Moreover, many of these finds have been worked on both sides and could thus be used alternately for the sequential manu-facturing of objects. Stacking moulds for rationalisation, as they are known in England, are however not represented. Quite a number of pieces show nothing but engraved preliminary drawings or fragmentary motifs, which indicates that these were the back parts of multi-piece casting moulds that did not have to be worked in such great detail. In addition to fine cutting tools divider calipers, engraving needles, various kinds of drills (e.g. spoon or spotting drills), milling tools as well as a lathe were standardly used. The fine-grained rock material of the limestone allowed for a highly precise and detailed cutting of the motifs’ mould cavities, which resulted in very complex and elaborately designed objects.
The casting moulds were mainly constructed from two or three components; however, there are several finds that consisted of four, five, or even eight parts. To ensure the accuracy of fit, holes were drilled in the mating surfaces of each matching moulding which then took up tin-lead dowel pins. For a secure fixation additional wires or bandages had to be wrapped around the moulds.
The casting material was poured through a sprue into the assembled moulds and runners or feed sprues led the material directly into one or multiple cavities. In this manner a large number of objects were serially mass-produced. Engraved vent holes or – in the case of complex objects – internally drilled vent channels, which were connected to the mating surfaces, facilitated the escape of air or gases trapped in the mould cavities. The Magdeburg foundry documents the earliest evidence of this venting technology so far, which was then apparently adapted by other foundries across the whole of Europe.
Apart from two moulds for a pilgrim’s amulet and a badge depicting the Crucifixion, motifs of profane nature predominate in the find material. It can thus be assumed that the foundry produced items for common bourgeois households. The range of motifs is extremely extensive and can be divided into following subject groups:
1. Small- and large-sized fibulae or brooches
2. Decorative fittings and mounts
3. Belt and strap buckles
4. Rings
5. Pendants
6. Buttons and beads
7. Toiletry (e. g. mirror cases)
8. Toys (miniature vessels and figures)
9. Spoons and bowls/plates1o. Chapes for the scabbards of knives or daggers
11. Micro scale or candlestick components
12. Box hardware and fittings
13. Miniature hatchets
14. Religious themes
There is a large variety of shapes within the individual groups, especially with the numerically predominant fibulae/brooches and fittings that together make up a total of c. 60 % of all moulds. The remarkably extensive range of motifs, which presumably was even larger originally, demonstrates that in the 13th century almost everything was cast, which was technically feasible and according to the customers’ desires. In doing so, there seem to have been hardly any technical difficulties, since it was possible to even produce the most complicated and sculptural objects by means of chill casting. Here, one was able to draw on long established and well practised techniques like full-mould and core casting, but more rarely used technologies like slush casting were also mastered. What is furthermore notable is that a lathe was used for creating and developing individual motifs (e. g. scale pans).
Of particular importance is the detected casting material, since it enables statements on a commercial orientation of the workshop. Besides a large number of dowel pins, corroded relics of tin-lead metal were also found in the casting cavities or sprues of several mouldings. In addition to this, a particularly high amount of residues was found in the vent channels, where the metal was pressed in during the casting process. Here, too, scientific analyses have revealed alloys of lead and tin, which were occasionally admixed with a little copper for an increase in hardness. In view of this fact it can be assumed that the entire find complex is associated with pewter casting and previously belonged to a tin foundry. This would thus be the earliest evidence of a presumably independent tin moulder. Even if the workshop produced tin objects (or white metal in general) it is still highly likely that many objects, especially the most elaborate and decorative ones, were modelled after precious metal realia. This is indicated among others by the reper¬toire in itself, but also for example by the imitated granulation works, filigrees, and gems at the finds, and the location of the foundry in a district otherwise charaterised by gold- and silversmithing. It may be suggested that all these workshops were part of some kind of pre-industrial production and trading system of a larger scale, which was made pos-sible by or required a correspondingly large urban market like the one in Magdeburg. This means that we are looking at an exclusively commercially oriented craft, which emerged in a completely different environment than the monastic goldsmithery described by Theophilus Presbyter in the early 12th century. In contrast to a serial and profane mass production, the monastic smithery focused on the manufacturing of elaborate and individual objets d’art for ecclesiastical demands. In this context, the above mentioned cast objects contribute to a change of our point of view regarding day-to-day life in the 13th century by means of their quantity as well as their professional, serial standardisation and compilation within a time horizon before 1280. They indicate a much richer everyday material cul¬ture in the urban milieu than was sometimes suspected. At the same time the Magdeburg foundry with its mass production both for a regional and presumably for a supra-regional market, marks an important step in the history of the development of the town and towards the guild-dominated trade structures of the late Middle Ages. Without doubt, this find of casting moulds thus represents a »treasure trove« in various aspects.
Die beiden hier vorzustellenden, zahlenmäßig dagegen eher bescheidenen Letternfunde vom Gelände des ehemaligen Franziskanerklosters übertreffen die Massenfunde an Bedeutung noch einmal beträchtlich, zumal nicht nur eine Zuordnung zu einer sehr früh und erfolgreich produzierenden Wittenberger Offizin möglich erscheint, sondern gleichzeitig auch bislang einmalige Notentypen gefunden wurden. Im Folgenden sollen zunächst die Fundstelle und die Fundumstände beleuchtet werden, bevor die Lettern selbst, insbesondere hinsichtlich ihrer Typometrie, Typografie und Metallurgie, behandelt werden. Aus den aufgefundenen Typen ergibt sich schließlich die Frage nach der historischen Zuweisung des archäologisch geborgenen Materials, zu deren Klärung alle verfügbaren Informationen zusammengetragen werden. Den Abschluss der Arbeit bilden musiktheoretische Betrachtungen sowie einige Bemerkungen zur Musikgeschichte der Reformationszeit, die gerade durch das Wittenberger Themenjahr 2012 »Reformation und Musik« (Abb. 2) im Vorfeld des 500. Reformationsjubiläums 2017 und eine musikgeschichtliche Ausstellung 2012 in den Franckeschen Stiftungen in Halle (Saale) besondere Aktualität besitzen."
and patination technique which are archaeometallurgically
treated within the framework of the Bronze Age
north of the Alps. The aspect of patination is here perceived
as a pure artificial procedure. On the one hand the investigation
should reveal how damascenings were realized on
bronze objects and if the observations provide evidence for
clarifying the provenance of the rarely used inlay technique
– a major question that is still unsolved. On the other hand
authentic methods are to be examined in detail that once
presumably allowed the patination of prehistoric damascened
items for enhancing the weak color contrasts between
base metals and inlays.
First of all the study shows that metal inserts were not
used frequently throughout the whole Bronze Age and in
the different areas north of the Alps. There were longer
gaps between the various stages of the era. In contrast platings
as a special form of damascening (»surface damascening
«) were applied continuously since period Montelius
II, yet this decoration is only a characteristic feature for the
Nordic circle that was not adopted in southern regions.
Using only electron as decoration metal throughout the
entire Bronze Age platings differ from damascenings with
metal inlays (»inlaid damascening«) in another point that
besides gold or electron they mainly availed of unalloyed
copper. Later the spectrum of inlaid damascenings was
enlarged by pewter, bronze, and iron. The investigation
demonstrates furthermore that the cavities for inlays on
most objects were already designed prior casting. However,
multiple evidence is found for reworking cast grooves. Only
in some cases the grooves were made exclusively by chasing
or engraving.
For Late Bronze Age artifacts it becomes clear on account
of stylistic and technical characteristics that the metal inlay
technique was practiced only by few workshops, nevertheless
probably having influenced each other. Such considerations
are much more difficult to proof for the Early and
Middle Bronze Age as there are less damascened pieces. Yet,
similar decoration patterns and techniques suggest interactions
between single craftsmen or workshops. Unfortunately,
the provenance of the damascene technique still
remains unclear despite this new investigation. Though, it
is at least unlikely that the polychrome decoration was
directly adopted from Mediterranean or even Greek prototypes,
but the stimulations rather have to be searched in the
Carpathian region. Finally, also a selfcontained development
somewhere in Central or Northern Europe cannot be
completely ruled out.
On the basis of patination experiments it can be shown
that in fact human urine is suitable for coloration of damascened
objects with copper inlays. Ideally, the medium produces
purple-black patinas on unalloyed copper while the
addition of elements such as tin or arsenic to copper gives
somewhat lighter appearances. High concentrations of tin
result in light yellow or slightly green-gray coatings. Even
these colors may have been desired in prehistory on tin
bronzes as they perfectly contrast with purple-blackish
patinated copper inlays. The investigated method therefore
emerges as a possible and formerly neglected way for patinating
many damascenings of the Bronze Age north of the
Alps. For this, however, some preconditions have to be fulfilled
which are discussed in detail in the following work.
The petrographical examination of thin sections from 15 stone samples with transmitted- and direct-light microscopy and the examination of rock powders has shown the use of a fine-grained Jurassic and/or Cretaceous marly limestone. For it the so called »Plänerkalkstein« of the northern foothills of the Harz Mountains is most probable. But also the »Solnhofener limestone« of the southern part of the Franconian Jura has to be considered.
Because there are no discolorations within the pouring system of all moulds it is clear that they cannot have served for the founding of bronze, gold and silver, which is confirmed by the results of the casting experiments. With energy dispersive X-Ray fluorescence analysis, light and scanning electron microscopy it could be shown reliably that 23 metal specimens of the cast system and several registration holes were made of pewter. Sometimes small amounts of copper might have been added to these tin-lead alloys. Because metal residues were available in the cast system at only six moulds, you cannot conclude on the general use of these metals for all of the 500 moulds. With discolorations outside the cast system and bright, powder like coatings on the complete surface at 60 % of all moulds an indirect reference to their use is given. Both observations indicate a heating of the whole mould. This is reinforced by scanning electron microscopic examination of thin sections and diffraction analysis of powder samples which revealed the »burned« character of the coating. Glowing tests with the Plänerkalkstein and Solnhofener limestone demonstrated that discolorations arise from 300 °C upwards, however, decomposition of calcium carbonate starts at around 700 °C. Thus all moulds with a bright surface coating must have been heated at temperatures of at least 700 °C. Such a measure can only be explained plausibly in connection with the metal cast and furthermore with the casting of pewter under consideration of the missing discolorations in the cast system. According to the results of the casting experiments it is quite improbable that the moulds had been heated at high temperatures like 700 °C before their use. However, a general explanation for the motives of a possible heating after founding cannot be given with the performed examinations. So some questions are still unanswered."
The collection of the Landesmuseum Natur und Mensch in Oldenburg contains seven blades of the Sögel-Wohlde types, which are discussed within the framework of an ongoing research project 'Origin, development and technology of the Bronze Age blades of the Sögel-Wohlde-district'. The aim of the project is to study the cultural and material relationships between the Nordic Circle and potential regions of influence such as the Carpathian Basin and the Northern Alpine region. The finds from Oldenburg, which predominantly consist of Sögel-type blades, form part of the story and are studied to correlate archaeological information such as typology, shape, find location including archaeometric data such as chemistry and isotopic signatures of lead, copper and tin. Even though Sögel-type blades were the most common finds around Oldenburg, they were far from uniform based on a large variation in design and decorations. Similar motifs of incised lines, dots and garlands continuously appear yet in different configurations. This suggests that there were no strict cultural norms that allowed for the fluid adaptation of both Nordic and foreign design elements that may have originated in the Carpathian Basin. Archaeometrically however, the blades are very uniform consisting of chalcopyrite copper containing nickel and arsenic as trace elements, suggesting the use of similar copper deposits that may have come from only a limited number of copper suppliers. However, future isotopic studies are required to make further statements which will provide further insights into the material and cultural interdependencies of the Sögel-Wohlde district.
Der Stellenwert des Magdeburger Komplexes ist aber nicht allein an seiner immensen Fülle zu bemessen. Große Bedeutung besitzt der Fund von steinernen Dauerformen v. a., weil er auf gießereitechnischer und metallurgischer Seite eine Reihe neuer, bisher ungeahnter Einblicke in das hochmittelalterliche Gießereiwesen erlaubt. Außerdem ist die potenzielle Verwendung der Gießformen zur Herstellung von Zinnobjekten bemerkenswert, die in dieser Intensität einmalig wäre und die mittelalterliche Handwerkskultur der Zinngießer – nicht nur derjenigen in Magdeburg – in einem völlig neuen Licht erscheinen lassen würde.
Im Gegensatz zum vorangegangenen Kapitel stehen im Folgenden vorwiegend die gießtechnischen und archäometallurgischen Aspekte der Gießformen im Vordergrund. Dafür war es nicht nur möglich, die Formen eingehend mikroskopisch hinsichtlich der Gesteinsart und auf Gebrauchsspuren hin zu prüfen, sondern auch Metallreste und Gesteinsproben von zahlreichen Exemplaren mit naturwissenschaftlichen Analyseverfahren zu untersuchen. Darüber hinaus wurden Gießversuche mit Vergleichsgestein in die Betrachtungen einbezogen. Diese spezielle Kombination erlaubt es, ein bisher beispielloses, konkretes Verständnis von der Funktion und Geschichte der Gießformen zu erhalten. Bevor jedoch auf die Ergebnisse der naturwissenschaftlichen Untersuchungen eingegangen wird, werden in Ergänzung zu den Darlegungen von G. Ditmar-Trauth (siehe Kap. Der Magdeburger Gießformenfund) zunächst noch einmal technische Kriterien herausgestellt und vertiefend erläutert.
The results of this research will be presented and discussed during four half-day sessions on geology and ore deposits, metallurgy and archaeology. In addition, there will be a welcome meeting on Wednesday evening, 14 March, a symposium dinner on Friday evening, 16 March, and the option for a tour through the Old City of Heidelberg on Saturday, 17 March 2018.
There will be only invited talks, but anyone interested is invited to participate the conference. Use the provided link for downloading the workshop programme and the registration form:
http://www.cez-archaeometrie.de/?p=1528
Neben der Datierung der Bleilettern anhand der Beifunde kann eine zeitliche Einordnung auch anhand typographischer Aspekte, etwa der Schriftart, besonders aber der Schriftausführung erfolgen. Unter den insgesamt 465 bestimmbaren Lettern fanden sich mit Antiqua, Fraktur und Schwabacher drei verschiedene Schriften. Bei erstgenannter gibt es neben den Lettern einer geradstehenden auch solche für eine kursive Form sowie eine Variante mit Kapitälchen. Dem Umfang im Letternkomplex nach zu urteilen dürfte die kursive Variante die Hauptschrift der Druckerei gewesen sein, deren typographische Merkmale sowie die an den anderen Schriften die Datierung der Bleilettern in das 16. bzw. frühe 17. Jh. stützen.
Eine weitere Datierungsmöglichkeit des Fundkomplexes bietet die sog. Graphemik. Hierbei handelt es sich um einen Bereich der Altgermanistik, in der man das Schriftsystem untersucht. Eine Datierung der Lettern allein aus dem Blickwinkel der Graphemik vorzunehmen, wäre sehr vage, da nur einzelne Buchstaben und Satzzeichen vorliegen. Erst gemeinsam mit der archäologischen und typographischen Betrachtung ergibt sich eine relativ sichere zeitliche Einordnung der Lettern. So sind beim Übergang vom Frühneuhochdeutschen (1350 – 1650) zum Neuhochdeutschen (ab 1650) graphemische Entwicklungen zu beobachten, welche beispielsweise die Großschreibung oder die Interpunktion und Kürzelzeichen betreffen. Auch Satz- und Sonderzeichen wie die Virgel (/), das Komma (,), das Fragezeichen oder die et-Ligatur (&), von denen mehrere als Lettern im Komplex erhalten blieben, können zur Datierung herangezogen werden. Das Fragezeichen ist z. B. zwar von Beginn des Frühneuhochdeutschen an bekannt, findet jedoch erst seit dem 16. Jahrhundert häufigere Verwendung. Damit und mit weiteren Aspekten wird ebenfalls eine Zeitstellung der Lettern in das 16./17. Jh. nahegelegt.
Ergänzend zur typografischen und graphemischen Betrachtung wurden die Lettern materialkundlich untersucht. Dazu konnten an 16 Typen Metallanalysen durchgeführt werden, die durchweg quartäre Legierungen aus Blei, Antimon, Zinn und Bismut erbrachten. Möglicherweise wurde dem Metall sogar noch Kupfer zugesetzt. Besonders hervorzuheben ist die Anwesenheit von Bismut, das zum ersten Mal an Lettern nachgewiesen werden konnte. Zuvor war seine Verwendung nicht durch Realien (z. B. Lettern aus Mainz) belegt, sondern nur aus zeitgenössischen Schriften wie Agricolas De natura fossilium bekannt. Vermutlich besteht hier ein Zusammenhang mit den nahegelegenen Bismutgruben im Erzgebirge und es scheint möglich, dass die Erfindung des Letternmetalls mit Bismut von Wittenberg ausgeht.
Die Legierungszusammensetzungen sind unterdessen recht uneinheitlich, dennoch lässt sich die Verwendung bevorzugter Mischungsverhältnisse nachvollziehen, die sich z. T. auch an anderen, unweit auf dem Arsenalplatz in Wittenberg gefunden Bleilettern wiederfinden lassen. Höchstwahrscheinlich lässt sich in den Legierungen eine Herstellung der Typen durch unterschiedliche Schriftgießer fassen, wobei offen bleiben muss, ob dies in einer oder in mehreren Gießereien erfolgte. Da die Typen stark schwankende Signaturhöhen aufweisen, könnte durchaus ein Hinweis auf unterschiedliche Schriftgießereien gegeben sein, zumal die Signaturen ansonsten deutlich einheitlicher wären. Möglicherweise äußert sich hierin aber auch ein chronologisches Kriterium, wonach die Lettern unterschiedlicher Zeitstellung sein könnten. Zum jetzigen Zeitpunkt bleiben die Aussagen jedoch noch beschränkt, da die Untersuchungen (auch an anderen Lettern) andauern.
We provide an overview of archaeometry. Short and crisp. That's boot camp.