Berlin Gold Hat
Encyclopedia
The Berlin Gold Hat or Berlin Golden Hat (German:
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 Berliner Goldhut) is a Late Bronze Age
Bronze Age
The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...

 artefact
Artifact (archaeology)
An artifact or artefact is "something made or given shape by man, such as a tool or a work of art, esp an object of archaeological interest"...

 made of thin gold leaf. It served as the external covering on a long conical brimmed headdress, probably of an organic material. It is now in the Neues Museum
Neues Museum
The ' is a museum in Berlin, Germany, located to the north of the Altes Museum on Museum Island.It was built between 1843 and 1855 according to plans by Friedrich August Stüler, a student of Karl Friedrich Schinkel. The museum was closed at the beginning of World War II in 1939, and was heavily...

 on Museum Island
Museum Island
Museum Island is the name of the northern half of an island in the Spree river in the central Mitte district of Berlin, Germany, the site of the old city of Cölln...

 in Berlin, in a room by itself with an elaborate explanatory display.

The Berlin Gold Hat is the best preserved specimen among the four known conical Golden hats known from Bronze Age Central Europe
Central Europe
Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...

 so far. Of the three others, two were found in southern Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, and one in the west of France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

. All were found in the 19th and 20th centuries.

It is generally assumed that the hats served as the insignia
Insignia
Insignia or insigne pl -nia or -nias : a symbol or token of personal power, status or office, or of an official body of government or jurisdiction...

 of deities or priests in the context of a sun cult that appears to have been widespread in Central Europe at the time..

The hats are also suggested to have served astronomical/calendrical functions (see below).

The Berlin Gold Hat was acquired in 1996 by the Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 Museum für Vor- und Frühgeschichte
Museum für Vor- und Frühgeschichte (Berlin)
The Museum für Vor- und Frühgeschichte , part of the Berlin State Museums, is one of major archaeological museums of Germany, and among the largest supra-regional collections of prehistoric finds in Europe...

 as a single find without provenance
Provenance
Provenance, from the French provenir, "to come from", refers to the chronology of the ownership or location of an historical object. The term was originally mostly used for works of art, but is now used in similar senses in a wide range of fields, including science and computing...

. A comparative study of the ornaments and techniques in conjunction with dateable finds suggests that it was made in the Late Bronze Age, circa 1,000 to 800 BC.

Description

The Berlin gold hat is a 490 g gold hat with a long and slender conical shaft and a differentiated convex foot, decorated all over with traced
Tracing
Tracing may refer to:* Tracing , a process by which a one demonstrates the ownership of property, with the intent to be awarded a claim based on this information...

 motifs, applied with small stamps and wheels. Its composition is very similar to the previously known Golden Cone of Ezelsdorf-Buch
Golden Cone of Ezelsdorf-Buch
The Golden Cone of Ezelsdorf-Buch is a Late Bronze Age artefact discovered in 1953 between the villages of Ezelsdorf and Buch in Southern Germany. A tall , cone-shaped object made of thin sheet gold, it is seen as belonging to a group of artifacts referred to as Bronze Age Golden hats...

.
At the bottom of the cone, the sheet gold of the Berlin hat is reinforced by a 10 mm wide ring of sheet bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

. The external edge of the brim is strengthened by a twisted square-sectioned wire, around which the gold leaf is turned upwards.

The overall height is 745 mm. The hat was hammered from a gold alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

 of 87.7% Au
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, 9.8% Ag
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, 0.4% Cu
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 and 0.1% Sn
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

. It was made of a single piece; its average thickness is 0.6 mm.
The cone is ornamented with 21 zones of horizontal bands and rows of symbols along all of its length. Fourteen different stamps and three decorated wheels or cylindrical-stamps were used. The horizontal bands were decorated systematically with repeated similar patterns.

The individual ornamental bands were optically separated traced ribs and bulges, mostly achieved with the use of cylindrical stamps. The bands of ornaments contain mostly buckle and circle motifs, most with a circular central buckle surrounded by up to six concentric circles.

One of the bands is distinctive: It is decorated with a row of recumbent crescents, each atop an almond- or eye-shaped symbol. The point of the cone is embellished with an eight-spoke star on a background of decorative punches.

An overview of the type and number of stamps used in the ornamental zones is shown on the right.

The meeting of the shaft with the foot is taken up by a wide vertically ribbed band. The foot is decorated with similar motifs to the cone itself. Near the reinforcing bronze band, it turns into a brim, also decorated with disk-shaped symbols.

Calendar

Modern scholarship has revealed that ornaments of the gold leaf cones of the Schifferstadt type
Golden Hat of Schifferstadt
The Golden Hat of Schifferstadt was discovered in a field near the town of Schifferstadt in Southwest Germany in 1835. It is a Bronze Age artefact made of thin sheet gold and served as the external decoration of a head-dress, probably of an organic material, with a brim and a chin-strap.- Cultural...

, to which the Berlin example belongs, represent systematic sequences in terms of number and types of ornaments per band.

A detailed study of the Berlin example, which is the only fully preserved one, revealed that the symbols probably represent a lunisolar calendar. The object would have permitted the determination of dates or periods in both lunar
Lunar calendar
A lunar calendar is a calendar that is based on cycles of the lunar phase. A common purely lunar calendar is the Islamic calendar or Hijri calendar. A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to...

 and solar calendar
Solar calendar
A solar calendar is a calendar whose dates indicate the position of the earth on its revolution around the sun .-Tropical solar calendars:...

s..

The functions discovered so far would permit the counting of temporal units of up 57 months. A simple multiplication of such values would also permit the calculation of longer periods, e.g. metonic cycle
Metonic cycle
In astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of very close to 19 years which is remarkable for being very nearly a common multiple of the solar year and the synodic month...

s.
Each symbol, or each ring of a symbol, representes a single day. Apart from ornament bands incorporating differing numbers of rings there are special symbols and zones in intercalary areas, which would have had to be added to or subtracted from the periods in question.

The system of this mathematical function incorporated into the artistic ornamentation has not been fully deciphered so far, but a schematic understanding of the Berlin Golden Hat and the periods it delimits has been achieved.

In principle, starting with zone Z_i, a sum is achieved by adding a relevant contiguous number of neighbouring sections: Z_i..Z_i+n. To reach the equivalent lunar or solar value, from this initial sum must be subtracted the sum of symbols from the intercalary zone(s) within the area counted.

The illustration depicts the solar representation on the left and the lunar one on the right. The red or blue fields in zones 5, 7, 16 and 17 are intercalary zones.

The values in the individual fields are reached by mutiplying the number of symbols per zone with the number of rings or circles incorporated in each predominant symbol. The special symbols in zone 5 are assigned the value of "38", as indicated by their number.
Example
Zone 12 is dominated by 20 repetitions of punched symbol No. 14, a circular disc symbol surrounded by 5 concentric circles.
Thus, the symbol has the value of 20 x 5 = 100.
The smaller ring symbols placed between the larger repetitions of No. 14 are considered as mere ornaments and thus not counted.


Through this system, the Hats can be used to calculate a lunisolar calendrical system, i.e. a direct reading in either lunar or solar dates, as well as the conversion between them.

The table can be used in the same way as the original Golden Hats. To determine the number of days in a specific time period (yellow fields), the values of the coloured fields above are added, reaching an intermediate sum. If any of the red intercalary zones are included, their sum has to be subtracted. This allows the calculation of 12, 24, 36, 48, 54 and 57 synodic months in the lunar system and of 12, 18, 24, 36, 48, 54 and 57 sun months (i.e. twelfths of a tropical year).
Example
To determine a 54 month cycle in the lunar system, the numerical values of the green or blue zones 3 to 21 are added, reaching a sum of 1,739 days. From this, the values of the red intercalary fields 5, 16 and 17 are subtracted, The result is 1739-142=1597 days, exactly 54 synodic months of 29.5305 days each.


The overall discrepancy of 2 days to the astronomically accurate value is probably the result of a slight imprecision in the Bronze Age observation of synodic and solar month.

Provenance and find history

The Berlin Gold Hat was put on sale in the international arts trade in 1995. In 1996, the Berlin Museum für Vor- und Frühgeschichte bought it as an important Bronze Age artefact. The seller claimed that the object came from an anonymous Swiss
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 private collection which had been assembled in the 1950s and 1960s. It assumed that the Hat was found in Southern Germany
Southern Germany
The term Southern Germany is used to describe a region in the south of Germany. There is no specific boundary to the region, but it usually includes all of Bavaria and Baden-Württemberg, and the southern part of Hesse...

 or Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

. No further details are known. The good preservation of the cone suggests that, like the Schifferstadt example, it must have been carefully filled with soil or ashes and then buried upright in relatively fine soil.

Manufacture

The Berlin Gold Hat is made of a gold alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

 of 87.7% Au
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, 9.8% Ag
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, 0.4% Cu
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 and 0.1% Sn
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

. It is hammered seamlessly from a single piece. The amount of gold used would form a cube of only 3 cm dimensions. The average thickness is 0.6 mm.

Because of the tribological
Tribology
Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear...

 characteristics of the material, it tends to harden with increasing deformation (see ductility
Ductility
In materials science, ductility is a solid material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire. Malleability, a similar property, is a material's ability to deform under compressive stress; this is often characterized...

), increasing its potential to crack. To avoid cracking, an extremely even deformation was necessary. Additionally, the material had to be softened by repeatedly heating it to a temperature of at least 750 °C.

Since gold alloy has a relatively low melting point
Melting point
The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...

 of circa 960 °C, a very careful temperature control
Temperature control
Temperature control is a process in which change of temperature of a space is measured or otherwise detected, and the passage of heat energy into or out of the space is adjusted to achieve a desired average temperature....

 and an isothermal heating process
Isothermal process
An isothermal process is a change of a system, in which the temperature remains constant: ΔT = 0. This typically occurs when a system is in contact with an outside thermal reservoir , and the change occurs slowly enough to allow the system to continually adjust to the temperature of the reservoir...

 were required, so as to avoid melting any of the surface. For this, the Bronze Age artisans used a charcoal fire or oven similar to those used for pottery
Pottery
Pottery is the material from which the potteryware is made, of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a pottery . Pottery also refers to the art or craft of the potter or the manufacture of pottery...

. The temperature could only be controlled through the addition of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

, using a bellows
Bellows
A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location.Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet...

.

Considering the tribologic conditions and the technical means available at the time, the production even of an undecorated Golden hat would represent an immense technical achievement.

In the course of its further manufacture, the Berlin Hat was embellished with rows of radial ornamental bands, chased into the metal. To make this possible, it were probably filled with a putty
Putty
Putty is a generic term for a plastic material similar in texture to clay or dough typically used in domestic construction and repair as a sealant or filler. Painter's Putty is typically a linseed oil based product used for filling holes, minor cracks and defacements in wood only...

 or pitch
Pitch (resin)
Pitch is the name for any of a number of viscoelastic, solid polymers. Pitch can be made from petroleum products or plants. Petroleum-derived pitch is also called bitumen. Pitch produced from plants is also known as resin. Products made from plant resin are also known as rosin.Pitch was...

 based on tree resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...

 and wax
Wax
thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...

 - in the Schifferstadt specimen, traces of this survived. The thin gold leaf was structured by chasing: stamp-like tools or moulds depicting the individual symbols were repeatedly pressed into (or rolled along) the exterior of the gold. At least 17 separate tools (17 stamps and 3 cylindrical stamps) were used.

See also

  • Golden hats
  • Golden Cone of Ezelsdorf-Buch
    Golden Cone of Ezelsdorf-Buch
    The Golden Cone of Ezelsdorf-Buch is a Late Bronze Age artefact discovered in 1953 between the villages of Ezelsdorf and Buch in Southern Germany. A tall , cone-shaped object made of thin sheet gold, it is seen as belonging to a group of artifacts referred to as Bronze Age Golden hats...

    , ca. 1000-800 BC
  • Golden Hat of Schifferstadt
    Golden Hat of Schifferstadt
    The Golden Hat of Schifferstadt was discovered in a field near the town of Schifferstadt in Southwest Germany in 1835. It is a Bronze Age artefact made of thin sheet gold and served as the external decoration of a head-dress, probably of an organic material, with a brim and a chin-strap.- Cultural...

    , ca. 1400-1300 BC
  • Avanton Gold Cone
    Avanton Gold Cone
    The Avanton Gold Cone or Avanton Cone is a late Bronze Age artefact, belonging to the group of Golden hats, only four of which are known so far....

    , circa 1,000-900 BC
  • Nebra skydisk
    Nebra skydisk
    The Nebra Sky Disk is a bronze disk of around 30 cm diameter, with a blue-green patina and inlaid with gold symbols. These are interpreted generally as a sun or full moon, a lunar crescent, and stars . Two golden arcs along the sides, marking the angle between the solstices, were added later...

    , ca. 1700-2100 BC
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