Im Steinbruch der Zeit. Erdgeschichten und die Anfänge der Geologie

Annual Exhibition of the Francke Foundations 2020

[Translate to Englisch:] Ammoniten sind häufig gefundene Versteinerungen.

Fascination of stone

Why is there an exhibition on the early history of geology in the Francke Foundations? There are two reasons for this.
Firstly, there is a cabinet with minerals in the baroque Wunderkammer - and such mineral cabinets belonged in each of these collections at that time, because the stones, the so-called 'inanimate nature', were also considered an important part of nature. Therefore, the exhibition is intended to explore the question of what significance stones and minerals had for the scientific and collecting culture of the early modern period.
On the other hand, the well-known geologist Christian Keferstein (1784-1866) from Halle donated his archive, library and collection of geological maps to the Francke Foundations. This collection has now been inventoried at the Study Center of the Francke Foundations and will be presented to the public in the context of this exhibition.

The exhibition tells the story of the early history of geology, when the natural history scholars became increasingly involved in the »quarry of time« and realized that the earth must be of an age unimaginable at that time. However, at that time they could not determine it exactly. On the other hand, we can find out by a quick look at the corresponding article on wikipedia that our earth is 4.55 billion years old. In determining this age, geoscientists were able to use the most modern technology to measure the radioactive decay of uranium and thus determine the age of meteorites or rocks. The researchers at that time had only their rationality and imagination. The result is a large number of »earth stories« that seem bizarre to us today.

Descend into the »quarry of time« and see the early modern geologists discover in natural history, mining and alchemy, collect and arrange, believe in the story of creation and this belief in nature measure, explore, measure and calculate, understand what their discoveries mean. We release visitors with a thought-provoking impulse to the face of the earth, which for the first time in the Anthropocene changed the face of mankind permanently.

Discover

In the Christian Middle Ages, people believed that the earth created by God was perfect from the beginning and has not changed since then, apart from the devastation once wreaked by the Biblical Flood. The age of the earth was not considered - the chronology of the Bible applied: God created the earth in six days.

Natural history

Although the Bible was the standard of Christian knowledge, one also wanted to experience the perfection of the world established by God through observation of nature, through 'reading in the book of nature'. The first medieval studies of nature were based on the traditional knowledge of antiquity. They were intended to demonstrate the omnipotence of God and remained valid until the early modern age. The scholars of natural history were now also anxious to determine the age of the earth. Their calculations were based on the information in the biblical scriptures, rather than on geological evidence.

The copperplate is showing the water reservoirs of the earth as Kircher imagined them.
Volcanic earth, copperplate in: Athanasius Kircher: Mundus subterraneus. In XII libros digestus. Quo Divinum Subterrestris Mundi Opificium, mira Ergasteriorum Naturae in eo distributio, verbo pantamorphon Protei Regnum, Universae denique Naturae Majestas [et] divitiae summa rerum varietate exponuntur [...]. Tomus 1+2 Amsterdam: Janssonius van Waesberge, ³1678, before 105. Halle, Francke Foundations: BFSt

The Jesuit priest Athanasius Kircher (1602-1680) was one of the most famous scholars of his time. In his work Die unterirdische Welt he speculated about the interior of the earth. According to his imagination, the body of the earth had bowels filled with water and fire. He was not interested in a theory of the origin of the earth, but in a description of the earth as a wonderful creation of God.

First geological findings were published around 1670 by the Dane Niels Stensen (1638-1686), Latin Nicolaus Steno. On hikes in Tuscany he had discovered that earth and rocks are stratified in analogous order over long distances. To explain this, he established the so-called law of storage: Older layers lie below, younger layers above - one of the basic principles of geology.
In addition, he recognized living organisms that were petrified in fossils. While dissecting a shark, he discovered that the so-called tongue stones, which are often found in certain sediment layers in the Mediterranean region, were petrified shark teeth. From this he concluded that these layers must have once been covered with water.

Mining

Further impulses to deal with geological phenomena were given by the mining industry. Since prehistoric times, people have extracted salt or metals from the upper crust of the earth, especially silver, copper, iron, lead and tin ores. Since ancient times, ores have been mined underground, mainly to extract metals. Their great importance for the economy and society led to an expansion of mining and technical innovations since the Middle Ages. It was George Agricola (1494-1555) who first put mining on a scientific basis with his writings around 1550.

The physician Agricola summarized the mining knowledge of his time in his 12 Büchern vom Bergwerck. In addition to the techniques of mining, he systematically described the minerals, their distribution and use, and the geology of deposits. He described how and with which techniques ores can be found and mined in the ground. He also thought about how the substances are formed in the earth's interior and looked for explanations of why and how some of these metals and minerals could reach the earth's surface naturally. The volumes first appeared in Latin and were translated into numerous other languages within a short time, including German in 1557. For over two centuries, it remained the standard work on mining and metallurgical technology.

In the dedication letter Agricola gives a short summary of the books:

»D[as] erste[ ] [Buch] enthält das, was gegen diese Kunst und gegen die Bergwerke und Bergleute […] gesagt werden kann. Das zweite entwirft ein Bild des Bergmannes und geht über zu den Erörterungen, wie man sie gewöhnlich über die Auffindung der Erzgänge anstellt. Das dritte handelt von den Gängen, Klüften und Gesteinsschichten. Das vierte entwickelt das Verfahren des Vermessens der Lagerstätten und legt auch die Ämter der Bergleute dar. Das fünfte lehrt den Aufschluss der Lagerstätten und die Kunst des Markscheidens. Das sechste beschreibt die Werkzeuge, Geräte und Erze. Das siebente handelt vom Probieren der Erze. Das achte gibt Vorschriften über die Arbeit des Röstens, des Pochens, des Waschens und des Dörrens. Das neunte entwickelt Verfahren des Erzschmelzens. Das zehnte unterrichtet die Bergbau Betreibenden darüber, wie man Silber von Gold und Blei von diesem und von Silber scheidet. Das elfte weist die Wege, wie man Silber von Kupfer trennt. Das zwölfte gibt Vorschrift für die Gewinnung von Salz, Soda, Alaun, Vitriol, Schwefel, Bitumen und Glas.«

Insights into everyday life in mining in the 16th century are provided by the pictures of the Annaberg mountain altar, of which you can see a copy in the form of a tapestry. Since the late Middle Ages, silver mining has made the Erzgebirge one of the most flourishing mining regions in Europe. Annaberg-Buchholz also profited from this. After silver deposits were discovered in 1491, the village received its town charter in 1497 and the church was built. Both the village and the church were named after the patron saint of the miners, Saint Anna.

Alchemy

Alchemy was also concerned with stones. In early modern times, alchemists were convinced of the idea that there was an anima mundi, a world soul, which controlled all growth and transformation processes in nature. In their view, metals and other substances also had their own soul. All things in nature, they believed, always strive for perfection. They regarded the interior of the "living earth" as a kind of womb, a place of constant growth and development, in which metals and minerals mature. The alchemists asked about the properties of these and were especially interested in the preparation and transformation of simple metals into higher-valued ones, for example into gold. The alchemists also explored the importance of the stone world for the production of medicines. In order to be able to produce medicines from metals, minerals or substances extracted from them, alchemists such as the physician Paracelsus (1493/94-1541) developed special processes. Thus alchemy became the basis for later chemistry and pharmacy.

Jasper is a quartz to which health protecting properties have been attributed since the Middle Ages. The natural scientist Conrad Gessner (1516-1565) wrote: »Jasper is a shield in front of the chest, the sword in the hand and the snake under the feet. It shields against all diseases and renews the spirit, heart and mind«.

Antimonite, formerly known as gray spit shine, was used as a basic substance for drugs that were not only used externally, e.g. for certain types of cancer. From the 16th century onwards, it was believed that taking medicines containing antimony purified and rejuvenated the human body. In the course of the 18th century, due to their great toxicity, these drugs were increasingly avoided.

Here too, in the Francke Foundations, a pharmacy was founded around 1700 and medicines were produced, most of which were developed by the people themselves. Today, several handwritten collections of prescriptions provide us with insights into the recipes according to which the in-house orphanage medicines were produced. One exception is that of the professed alchemist Samuel Richter (born in the 2nd half of the 17th century, died after 1722, pseudonym: Sincerus Renatus). He did not belong to the personnel of the medicine expedition, but was demonstrably in contact with the Halle orphanage and exchanged ideas with them in the pharmaceutical-alchemistic field. In addition to recipes dealing with the Lapis Philosophorum, i.e. the philosopher's stone, he also mentioned numerous regulations for the 'improvement' of metals (their transformation into purer, nobler metals such as silver or gold).

Handwritten poem of Richters
Entry on the »Virtues of Gemstones«, in: Samuel Richter: Recipe Collection, Manuscript, Halle, 1712. Halle, Francke Foundations: AFSt

Transcription

Tugenden der Edelsteine.
Der Jaspis macht vom Bluten frey
Des Hyacinthus Gaben besämftigen
die kalte Pest,
Der Amethist hält Nüchtern,
Ein Türckis heilt die Wunden fest,
Saphir dint den Gesichtern, Er
ändert deren Pocken Spur, daß
Sie nicht mehr Zusehen.
Smaragd ist wieder rothe ruhr,
Onis lässt Urin gehen
Dorth steht der Diamant oben an,
dem weichet alle Stärcke, weil
man ihn nicht bezwingen kan durch
Macht der Hände Werke.

In his work Natur-Kündigung Der Metallen, the economist and alchemist Johann Joachim Becher (1635-1682) discusses in detail, »[w]ie die Metallen gezeuget/ dann geboren/ und endlich aufferzogen werden.« The frontispiece of the volume gives an impression of the wealth and complexity of alchemical imagery:

In the crown of the tree, the alchemical symbols of the six metals gold, silver, mercury, copper, iron and tin are each located on a star-shaped background. The generation process of the seventh metal, lead, is symbolically represented. The one-legged man, who in alchemical imagery stands for the planet Saturn, to which the lead was assigned, lets a liquid fertilizing the earth flow out of a vessel with the symbol for lead (»ALO« = Latin for »I nourish«). The trunk of the tree bears the inscription »CONCIPIO« (»I receive«). On the crown of the tree the rays of the sun hit the tree, in which the word »GIGNO« is written (»I engender«). The bodies of heaven and earth, connected by the world soul, thus produce the metals which the miner (in the engraving on the right, leaning on a spade) can extract and process (»Elaboro« = I work) as soon as he has waited for their ripening process.

Collect

This section is about collecting stones which, like the objects from the other two 'realms of nature': flora and fauna, were an indispensable part of the art and natural history cabinets in the early modern period. Because they were 'inanimate' and not living beings, stones were considered the lowest form of natural phenomena. On the other hand, they were regarded as an initial state and thus as the basis of all animate nature. All other forms of existence were based on them, and in a certain way the stone remained contained in all higher forms of existence and beings of nature. This significance for the cosmos motivated the collecting of stones and their presentation in the natural history cabinets.

 

Some collectors found their own classification systems and published them, some in catalogs of their collections. Some of these systems fell into oblivion, others found imitators.

Johann Lucas Woltersdorf (1721-1772) was a theologian and avid collector of minerals. He developed and published his own system of classification for his collection. However, this never attained greater scientific significance.

Johann Ernst Immanuel Walch (1725-1778) was professor at the Faculty of Philosophy of the University of Jena and was interested in geological and paleontological topics, for which he also published. His geological and palaeontological collection, which he describes in this collection catalog, is today part of the collections of the University of Jena.

In the collections, the stones had to be assigned a specific location, because the place of the individual exhibit defined its significance in the ensemble of a collection - in this respect, the furnishing of collection rooms with their cabinets and shelves was always also an instrument of the spatially organized order of knowledge and the world.

The green cabinet contains the stone collection of the Wunderkammer.
The Mineral Cabinet in the Cabinet of Artefacts and Natural Curiosities of the Francke Foundations.

An example of the storage and presentation furniture for minerals of that time is the Mineral Cabinet in the Chamber of Art and Natural History of the Francke Foundations, which was built and furnished around 1740. Concealed by the doors is the serial number »1.A«. The cabinet is surrounded on the right by the cabinets »2.B« and »3.C«, which present plants, and on the left by »4.D« and »5.E«, which contain animals. Thus, given the numbering, one can see that the minerals were considered the beginning or the basis of the other phenomena in nature and are surrounded by these, the plants and animals. The cabinet is divided into three areas: at the bottom is the storage area with the drawers where the less spectacular pieces were kept. Above it is the presentation area with the glass doors for the more spectacular objects and above it is the artistic crowning painting that indicates the contents of the cabinet. From the collection catalog of 1742 we also know that the mineral collection was arranged according to the system of the Swedish biologist Carl von Linné. His system of arrangement for animals and plants is still in use today, but that for minerals did not prevail in the long run.

In the special exhibition, the pieces lie illuminated in a showcase.
Selected pieces from the mineral cabinet of the Cabinet of Artefacts and Natural Curiosities in the exhibition »Im Steinbruch der Zeit«.
 Quartz crystals overgrown with ore
Quartz crystals overgrown with ore
Petrified sea urchins
Petrified sea urchins
Ammonoids in rock
Ammonoids in rock
Mussel patch with trace fossil (creeping path)
Mussel patch with trace fossil (creeping path)
Sintered bird's nest
Sintered bird's nest
  
Copper engravings in Mylius' book show the »Kupferschiefer-Heringe«.
Of the Eißlebischen Kupffer-Bergwerck and its Figurirten Schieffern (petrified fish (Palaeoniscum freieslebeni) in copper slate), copperplate in: Gottlieb Friedrich Mylius: Memorabilium Saxoniae Subterraneae Pars Prima. I[d] e[st] Des Unterirdischen Sachsens Seltsamer Wunder Der Natur Erster Theil: Worinnen die Auf denen Steinen an Kräutern, Bäumen, Bluhmen, Fischen, Thieren, und andern dergleichen besondere Abbildungen, so wohl Unsers Sachsen-Landes, als deren so es mit diesen gemein haben, gezeiget werden. Leipzig: Groschuff, 1709, Fol. 4. Halle, Francke Foundations: BFSt

Gottlieb Friedrich Mylius (1675-1726) had studied law in Halle and Leipzig and worked as a lawyer in Leipzig. Probably also motivated by the collections in the Francke Foundations, he set up an important natural history cabinet and systematically collected minerals from the Saxon region. In his collection catalog of minerals, the so-called copper slate herrings of the Mansfeld region are also presented.

In the mines of the county of Mansfeld masses of well preserved fossilized fish were found in the copper slate. These were popular collector's items in the early modern period and often depicted in collection catalogs. Colloquially they were called copper shale herrings. The biological name of the now extinct bony fish is Palaeoniscum freieslebeni.

The two objects below come from other cabinets in the chamber, but are related to minerals and mining.

A so-called hand stone is an art object made of minerals that represents a mine. The handstone is missing the crowning miner figure or the final cross. On the upper floor there is a reel or winch with a windlass servant, other servants are only fragmentarily preserved. On the middle level there are three miners at work in the mine, below a seated miner is mining ore, one miner comes out of a gallery, another one is moving a wheelbarrow.

Also the Patience bottle shows a mine. Such bottles were produced by miners in the Erzgebirge in their spare time and were quasi the forerunners of the ship in a bottle. The miners in the Erzgebirge and their families used to assemble everyday situations in mining in such patience bottles on long winter evenings. The sale of the bottles brought a welcome extra income. The costume of the miners depicted here is that of the Saxon Erzgebirge. The making of such dishes with scenes from the mining industry was a speciality of the region.

Keferstein Collection

In 1850, the Hall geologist Christian Keferstein (1784-1866) donated his mineralogical collection to the Francke Foundations. It comprised more than 10,000 objects in 19 collection cabinets - the collection is now in the Institute of Geosciences and Geography at the Martin Luther University Halle-Wittenberg, the collection cabinets have been lost. It consisted of two parts, a mineralogical collection, which was arranged according to the system of the mineralogist Abraham Gottlob Werner (1749-1817), and a geological collection, whose order referred to the regions of origin of the pieces.

Petrified wood
Petrified wood
Sedimentary rock with cavities filled with calcite
Sedimentary rock with cavities filled with calcite
Medal from Terra Sigilliata
Medal from Terra Sigilliata
Four different crystal models
Four different crystal models
Cinnabar Ore
Cinnabar Ore
Folded, laminated metamorphic rock
Folded, laminated metamorphic rock
Plaster crystals, so-called plaster rose
Plaster crystals, so-called plaster rose
  

Believe

The relationship of the Pietists of Halle to geology was always connected with the theology of physics, which means »natural theology« and means that the Pietists encouraged natural and scientific studies in order to realize how perfect God had arranged the world. The aim was to link all natural physical phenomena with Christian doctrine. The knowledge about God's creation was now gained through observation, experiment and the acceptance of general laws of nature. Physicotheologists regarded the acquisition of knowledge of natural history as their God-given mission and a way of praising the Creator. At the center of this was the biblical Flood as a fundamental upheaval in the shape and life of the earth. The correct interpretation of the Flood and its consequences promised answers to questions about the origin of minerals, rocks and fossils.

The Flood also offered an explanation for the fossilized animals and plants that were found even on mountains and far away from any body of water. Originally, these fossils were not regarded as fossils but as games of nature (lat. lusi naturae). Also the presence of sediment layers above sea level, whose formation by water was already assumed at that time, could be explained in this way.

Six different reptiles together in a very small space.
Haptodus baylei Gaudry (syn. Pantelosaurus saxonicus V. Huene), group of 6 reptiles, cast, Lower Rotliegend (300 -275 mill. years), former Queen Carola Shaft near Freital, Saxony. Halle, Martin-Luther-University Halle-Wittenberg, Institute for Geosciences and Geography

One problem of the theologically inspired research of that time, however, was that petrified plant and animal species were found that did not correspond to the plant or animal species of the present day. That these might be species that were extinct was unthinkable to the Pietists. According to their belief, God had completely arranged the world so that there could be no change of species or evolution. They accepted the assumption that these species did exist, but in distant regions of the earth and still undiscovered.

The Pietist Friedrich Christian Lesser (1692-1754) was also an outstanding representative of physics theology and was close to the Pietists of Halle. Lesser had studied theology in Leipzig and Halle, and as a pupil of August Hermann Francke he was influenced by Pietism. From 1715 Lesser was a pastor in his home town of Nordhausen. There he began to build up his own collection of natural history, focusing on minerals and fossils. The portrait shows him in front of a cabinet in his collection.

Lesser's main work, Lithothealogie, as an encyclopedia of the stone kingdom, summarizes the mineralogical-geological knowledge of the first half of the 18th century. It describes not only the properties of the stones, but also their significance for humans, animals and plants. In addition, it deals with their usefulness for people in the past and present and deals with the miracles related to stones that have been handed down in the Bible. Lesser himself understood his work as a theological treatise, by which the phenomenon of stones was to be grasped above all inwardly and spiritually.

The thesis that these animals and plants exist in distant parts of the world, and that they had just not yet been discovered, was also advocated by the Querfurt theologian and deacon David Sigismund Büttner (1660-1719). In the environment of Halle's pietism, it was he who dealt most intensively with palaeontological phenomena. He corresponded with August Hermann Francke and sent him a large number of objects for the natural history cabinet of the orphanage. His main work on the »Deluge« was to serve »the natural knowledge of God and his creature«.

Johann Joachim Lange und pietistisches Nützlichkeitsdenken

In Halle itself it was Johann Joachim Lange, the son of one of August Hermann Francke's closest confidants, who dealt with mineralogical-geological and mining issues. In 1723, he was offered a chair for mathematics at the University of Halle, but it is said that he was more interested in natural history. The first doctoral thesis on the geology of the region around Halle, which is exhibited here, was published in his environment. The author Johann Jakob Lerche was mainly interested in the economically useful resources in the soil.

Here, Johann Joachim Lange ties in with his own publications, thus demonstrating a usefulness thinking typical of Pietism: nature is arranged by God to be of use to man. For Lange, this leads to the requirement that man should explore nature from the aspect of usefulness and then exploit it. For this reason, Lange has given lectures on mining science at the university and has encouraged young people in publications to deal with questions of regional geology.

Here the piece of hard coal stands for the usefulness thinking of Lange and the Pietists. Since the beginning of the 18th century, hard coal began to replace the increasingly scarce and expensive wood or charcoal as fuel for salt boiling in Halle. This hard coal was mined in mines near Wettin and Löbejün, north of Halle. Especially the economic-cameralistic literature from the environment of Halle's pietism repeatedly emphasized its usefulness for the city's economy.

Lange also dealt with questions of mineralogical systematics. The trigger for this was the famous work Systema Naturae by the Swedish naturalist Carl von Linné (1707-1778) from 1735, in which he developed for the first time a uniform system of hierarchical order categories for all »Drey Reiche der Natur«. Johann Joachim Lange studied Linné's systematics very intensively and also taught it at the university. His probably best known and most influential work was the publication of the Systema Naturae in Latin and German, for many years the only German translation of this fundamental work.

The engraver, painter and naturalist Gottfried August Gründler (1710-1775) had published the German version of Linnés Systema Naturae in 1740 together with Johann Joachim Lange. At the same time, he had already applied the Linné system to the reorganization of the Chamber of Art and Natural History of the Glauchaschen Anstalten, including the organization of the mineral collection. He made copperplate engravings for this history of the earth by Krüger (1715-1759), a professor of medicine in Halle. This work also stands in the physicotheological tradition of natural history at the price of God.

Explore

This chapter is dedicated to the development of geology into a recognized science and is divided into two parts: While in the 18th century the Bible and Deluge theories were still at the forefront of the debate, »geognosy«, as it was then called, soon detached itself more and more from the traditional references to the Bible or combined it with new theories about the construction and development of the solid earth's crust. Pure speculative thinking was now replaced by empirical experience in the field, which had to be interpreted correctly.

Geology 1750-1800

Natural history, mining, alchemy, the passion for collecting and belief in creation: around 1750, geology began to develop as an independent natural science on this basis. This was already evident in the many theories of the 18th century, which speculated on the course of the earth's history and sometimes told of huge underground fires. In most cases, however, they focused on the biblical Deluge, the effects and mechanisms of which were passionately debated by nature-researching physicians, theologians and scholars, including world-famous universal geniuses such as Gottfried Wilhelm Leibniz, but also nature-researching professors such as the Hall physician Johann Gottlob Krüger (1715-1759).

In the history of the earth, Johann Gottlob Krüger, a natural scientist from Halle, took the view that the Deluge could never have caused such serious changes as can be observed on earth today. Instead, Krüger considered three major pre-Deluge events to be decisive, which must have taken place one after the other: a general flood, a global earthquake catastrophe with fires, which led to the extinction of early aquatic inhabitants and the formation of slate rocks, and several local earthquakes, which finally shattered the rock world. But he did not know exactly when all this was supposed to have happened.

Johann Esaias Silberschlag (1721-1791), pietistically oriented theologian and professor of hydraulic engineering, tried to show in his Geogenie that the statements of the Bible and the findings of the exact natural sciences do not contradict each other, but illuminate each other. The Deluge, fed by a huge reservoir of water in the earth's interior, is at the center of his theory, to which he also added detailed plans of the ark. The division of the pairs of animals in the rescuing ship corresponds to Carl von Linnés Systema Naturae.

In the second half of the 18th century, the typical methods of geology became established: minerals and rocks were determined on the basis of their sensual and chemical properties, rock layers were examined stratigraphically and the first geological maps were produced.

The two-part colored map of the Saxon Erzgebirge shows typical scenes from the mining industry, which has a tradition of over 800 years in this region and has shaped its economic and cultural development. The knowledge and techniques of mining in the Erzgebirge were trend-setting for geology on its way to science, especially in the German-speaking countries. After the Seven Years' War, mining experienced a real modernization push. Mining academies were founded to educate experts on a scientific basis in order to optimize the mining of raw materials for the economic well-being of the country. The famous mining academy in Freiberg, Saxony, was founded in 1765 and quickly became the center and international model of this development.

This is, as far as known, the first, albeit still rough, geological map of Kursachsen. It illustrates the geographical distribution of the rock types using different colors, signs and letters. It was drawn and published by the Saxon mining captain Johann Friedrich Wilhelm von Charpentier (1738-1805), who taught at the mining academy in Freiberg. It was fundamental for the comprehensive geognostic investigation of Saxony from the end of the 18th century onwards.

The impressive educational model of the drift shaft of the King David Mine near Annaberg, dating from around 1800, was once used to demonstrate the techniques and functions of underground ore mining to students of the mining academy. As the shaft is not straight but s-shaped in accordance with the mountain folding, it is referred to as warped. The half-timbered house above it, which houses the Göpel - a water-driven winding machine - is also clearly visible.

The figurehead of the Freiberg Academy was the mineralogist and mining inspector Abraham Gottlob Werner (1749-1817), whose finely crafted bust of Meissen porcelain watches over the volcanic objects here. He was undoubtedly the best known and most influential geologist of that time, attracting students from all over the world to the small mining town in the Electorate of Saxony. Among them were the Romantic Novalis (1772-1801), the explorer Alexander von Humboldt (1769-1859) and the geologist Leopold von Buch (1774-1853). Werner not only established geognosy, as geology was then called, as an empirically working empirical science of experience, but was also the main representative of Neptunism. The followers of this once popular theory of rock formation were convinced that almost all rocks were gradually formed in a primordial ocean and deposited when the water level fell, resulting in typical stratigraphic sequences over time. They had closely observed these in the Central German mountain landscapes. Active volcanoes, which were not to be seen there anyway, were considered by the Neptunists to be secondary phenomena, without any significance for the history of the earth. The older theory, however, represented by the volcanists, considered fire-breathing volcanoes to be the most important rock-forming force, even if they could only speculate about their function. After his death, Werner's Neptunistic theses quickly lost their importance, but his methods of geognosy shaped the research practice of the young geology well into the 19th century.

Werner distinguished the color shades very precisely.
Color overview for mineral determination, in: Abraham Gottlob Werner: Von den äußerlichen Kennzeichen der Foßilien. Leipzig: Crusius, 1774. Halle, Francke Foundations: BFSt

Werner's theory of characteristics served the systematic description of the external properties of minerals, which had to be recorded as completely as possible with all senses on the basis of color, smell, taste, sound, gravity, cold and hardness in order to be able to name and classify them reliably. With this, he wanted to give the researching geognosten a simple tool in his hands to quickly determine minerals and rocks found in the terrain - with the appropriate practice. He considered color to be the most important and reliable determining characteristic, for which he developed a particularly detailed terminology that was to cover all variants and gradations.

Werner has published very little, but in over 40 years of teaching he has passed on his knowledge to almost 600 students, whom he encouraged to take precise notes in his lectures. Some of these lecture notes have survived to this day. Ernst Friedrich Germar (1786-1853), who had studied in Freiberg under Werner, gave his notes to his brother-in-law Christian Keferstein (1784-1866), who in turn copied them neatly and then used them for self-study. Werner's lecture on geognosy dealt with the construction of the solid body of the earth and the natural sequence of rocks in the sense of Neptunism, which he explained to his students using examples, as the sketch of the deposited layers on the Brocken in the Harz Mountains shows.

The Basalt Controversy

Around 1780, the question Did basalt come into being in water or in fire? sparked off a heated dispute between Neptunists and volcanists that lasted for many years and became famous as the basalt dispute, which we even encounter in Goethe's Faust. It can be regarded as the founding debate of modern geology in Germany, so to speak. In the end, victory was won by the volcanists, whose view finally became generally accepted in the early 19th century. For their research, among others in the Eifel and the French Auvergne, left little doubt that basalt could by no means be a child of water. Today we know that basalt is a volcanic rock that is formed when thin magma emerges from the earth's surface or from the ocean and cools down relatively quickly to form basalt lava. The oceanic crust consists mainly of basalt, but the fine-crystalline rock is also frequently found on the mainland, for example in the German low mountain ranges.

When lava cools down more slowly and contracts, tensions can arise in the rock. The shrinkage cracks that occur in this process run perpendicular to the cooling surfaces, resulting in the formation of polygonal - often hexagonal - prismatic columns. This columnar basalt can be found all over the world, in Germany for example in the Eifel, in the Erzgebirge or in Upper Lusatia, where this specimen also comes from.

Famous are the large basalt pillar areas in Northern Ireland and on the Scottish west coast, such as on the small island of Staffa. Scipione Breislak's (1750-1826) Atlas of Basalt Formations showed contemporaries the richness of the sometimes bizarre basalt landscapes of Europe and Mexico on high-quality copperplate engravings.

The volcanists attributed central importance to fire-breathing volcanoes and supposedly large underground fires for the formation of rocks, although they did not yet recognize the underlying principle of rising rock melts (magma).

Werner and his followers and opponents were still strongly oriented towards the idea of classical stratovolcanoes with large craters such as Etna or Vesuvius, which produced ash and lava flows and were always popular destinations for research and cavalry tours.

Geology 1800-1850

Initially, in the second half of the 18th century, research methods of geology had gradually developed, such as mineral and rock analysis, the study of rock layers in the terrain, the preparation of geological maps or the description of fossils. Now, around 1800, geology was in its heyday and developed into a veritable fashion science. Elaborate research trips and excursions often led to completely new insights and were indispensable for every geologist who thought highly of himself.

Many geologists of the early 19th century, known as catastrophists, believed that the earth had repeatedly been fundamentally changed by enormous natural disasters in the past. Some of them considered the biblical Flood to be the latest and for the time being last catastrophe that has shaped the present appearance of the earth. After 1830, the conviction prevailed that the earth had been undergoing constant change since its creation, which was unspectacular, extremely slow and often deep inside. Even if it cannot be observed directly, it is still able to bring forth and remove mountains - through periods of time beyond all imagination. The »Discovery of time« was one of the most important achievements on the way to modern geology.

Catastrophism

Georges Cuvier (1769-1832) is considered the main representative of the catastrophe theory, which was still popular in the early 19th century. His research was groundbreaking for modern paleontology, as he succeeded in reconstructing many extinct animal species with astonishing accuracy, often using only a few fossilized bone remains. Since these only occurred in certain layers of rock, it seemed clear that the earth must have changed by leaps and bounds again and again. However, the first fossil skeleton of a plesiosaur, a long-necked marine reptile, was discovered and meticulously uncovered by a woman in 1821: the fossil collector Mary Anning (1799-1847), who a few years earlier had also excavated the first skeleton of a fish dinosaur (Ichthyosaurus).

Aktualismus

A vehement opponent of Cuvier was the British geologist Charles Lyell. He claimed that Cuvier and all the other so-called catastrophists completely misinterpreted the geological findings. What at first glance appeared to be a sudden, violent upheaval was in reality the result of infinitely slow, uniform and continuous processes. In an eternal cycle, landscapes and life worlds are created that change and then vanish again. According to Lyell, the same geological forces and principles that were effective millions of years ago still shape the earth's surface today. Lyell's principle of constant change, which is barely visible but can be reconstructed on the basis of a few traces, is called uniformity or actualism. Both views, catastrophism and uniformitarianism, stood opposite each other in the first half of the 19th century.

Banded ores are iron-bearing marine sedimentary rocks with magnetic properties that were formed in the early days of the earth and are therefore among the oldest rocks on earth. As there was no oxygen in the sea water and the atmosphere, they are not oxidized. Under today's conditions on earth they can no longer be formed, thus disproving the thesis of actualism.

The illustrations from the Agenda Geognostica show selected tools, devices and measuring instruments of early 19th century geology: geological compass with degree arc (12), degree arc with plumb line (13), simple clinometer (14), differential barometer (15), register thermometer according to James Six (16) and Daniel Rutherford (17). In addition to the obligatory hammer, the main tool of the geologist, the compass with degree bow and the barometer for measuring altitude were indispensable. The book also deals with the handling and practical suitability of the expensive and sensitive equipment and recommends reliable manufacturers. Good instruments, which facilitated the mapping work, were indispensable for the geologist. They provided more and more, and above all more accurate data to unlock the secrets of the rock world.

Ideal profile representations of the earth's crust, which became more and more popular in the course of the 19th century, were intended to clearly illustrate all essential geological conditions and processes at a glance. They reflect the state of knowledge at the time of their creation, but also the authors' individual views on the driving forces and principles of the earth's history.

In 1830, the English geologist Henry Thomas de la Bèche (1796-1855) created the first reconstruction of a prehistoric world with plants and animals in his watercolor, which was later often copied and adapted. He based his work on finds from southwest England. Between pterosaurs, turtles and crocodiles, Plesiosaurus and Ichthyosaurus, which had been excavated for the first time by Mary Anning, are found - involved in a dramatic battle.

Understand

Around 1800, geology developed into a veritable fashionable science that attracted both natural scientists and laymen, including the Haller jurist Christian Keferstein (1784-1866), to whom this chapter is dedicated. Even as a child he was enthusiastic about stones and started an extensive collection, which he later donated to the Francke Foundations. As an amateur geologist, he gained a certain reputation, among other things through his ambitious pioneering project of a geological map of all of Germany.

Aluminite was first found on the grounds of Halle's orphanage in the early 18th century, during construction work in the Botanical Garden of the Royal Pedagogy. In 1730, the Hallesian physician Johann Jakob Lerche (1708-1780) gave a first description of the rare sulfate mineral in his Oryctographia Hallensis - still called »Lac lunae« (lat. Moon milk).

In his first scientific work, Christian Keferstein dealt with the aluminite and described further occurrences in the vicinity of Halle, among others at Morl. Worldwide only about 60 sites of the mineral are known today, which is also known as 'Hallische Erde'.

Unfortunately we do not know what Christian Keferstein looked like. Perhaps we can imagine him a little bit like the geologist in the picture by Carl Spitzweg (1808-1885), who is completely immersed in the devotional contemplation of a stone. »Bald wurde der Wanderstab auch weiter gesetzt; […] stets hatte ich den Ränzel auf dem Rücken, den Hammer in der Hand und war mit Steinen beladen«, Keferstein wrote in his memoirs. Spitzweg's researcher seems a bit out of time and rather quirky with the botanizing drum, which is not suitable for collecting stones. Keferstein, on the other hand, was up to date and was long considered a respectable and committed geologist.

Biography Christian Keferstein

Keferstein came from an old papermaking family, his great-grandfather was once the tenant of the paper mill on the banks of the Saale in Kröllwitz. But Christian, who grew up in an enlightened and educated household, was not to become a paper miller, but a lawyer, just like his father. Soon after his university studies, Keferstein began practicing law; successfully and with a considerable income, but without real passion. Since childhood, his real love was the world of stones, which was sparked by a mysterious attic find: a box with sparkling minerals that once belonged to his mother and to which the boy devoted himself enthusiastically from then on. This small treasure formed the basis of his later large collection. As a pupil and student, Keferstein spent every spare minute studying the natural sciences, visiting the city's mineralogical collections, listening to lectures in chemistry and physics, and roaming the area around Halle in search of exceptional specimens for his rock collection. Later, when he was already in the middle of his professional life, he attended the natural philosophy colleges of the charismatic natural scientist Henrik Steffens (1773-1845). In his free time he devoted himself entirely to mineralogy and geognosy, whose tools he gradually acquired. He was supported in this by his brother-in-law Ernst Friedrich Germar, who was mainly interested in fossil insects and gave Keferstein his lecture notes from student days for self-study. Germar had studied mining in Freiberg, Saxony, under the mineralogist and chief neptunist Abraham Gottlob Werner, whom you have already met in the fourth department. Keferstein, who preferred to observe nature rather than sit at his desk, now undertook ever more extensive journeys, which he reported on to the Nature Research Society and increasingly in his own writings.

As a married Royal Prussian Commissioner of Justice and Court Councillor with a considerable fortune, Keferstein gradually withdrew from the legal service in the 1820s to live exclusively for science. He made it his main task to wander through the many German regions with their low mountain ranges, as well as the Alpine mountains, and to conduct geological investigations. In doing so, he met the most important natural scientists and geologists of his time - Johann Carl Wilhelm Voigt (1752-1821), Ami Boué (1794-1881) and Carl Cäsar von Leonhard (1779-1862), for example - with whom he exchanged observations and gradually established a considerable network of correspondence.

On his numerous geognostic journeys, he wanted to gain a thorough overview of the geological conditions of all of Germany and Central Europe. The knowledge he gained in the process finally resulted in a project that kept him busy for ten years: a color geognostic atlas together with a scientific journal. Colored geological maps were nothing new in themselves, but had hitherto been limited to certain regions and primarily listed economically exploitable mineral resources. However, what Keferstein had in mind, namely a general geological map of Germany, supplemented by special regional maps, was unique at the time. Together with a scientific publishing house in Weimar, which took over the printing and provided topographic maps to which Keferstein transferred the boundaries of the rock formations, the first geological overview map of the whole of Germany was produced.

It was particularly difficult to choose the right colors to clearly and aesthetically highlight the various rocks. None other than Johann Wolfgang von Goethe, who was also enthusiastic about geology, was won over to design a balanced color system, which Keferstein was very proud of. Under the title Teutschland geognostisch-geologisch dargestellt, mit Charten und Durchschnittszeichnungen, die eine geognostischen Atlas bilden Karten and magazines in seven volumes with a total of 20 booklets appeared. The hoped-for success, however, did not really materialize, as they sold only moderately. To make matters worse, the renowned geologist Leopold von Buch had published a far more detailed competing product that suddenly eclipsed Kefstein's efforts. It was the premature end for the ambitious map project, which the amateur geologist Christian Keferstein had largely managed on his own.

However, this defeat did not mean the end of his work: until 1840 he continued to travel through the mountains of Central and Eastern Europe, publishing his findings and even publishing a highly respected history of geognosy since its beginnings. With advancing age, however, the exhausting wandering became increasingly difficult for him. He looked for new fields of activity, which could be explored comfortably from his desk if necessary, and found them in ethnography, archaeology and the history of language. Keferstein died in his hometown on August 28, 1866, already almost forgotten by experts.

Today, his preserved testimonies and collections, like the many rocks and minerals, his research library and the fascinating maps, are a valuable treasure that allows exciting insights into a natural science in the making.

Johann Wolfgang von Goethe (1749-1832) assured in his letter that he would follow Keferstein's work on the geological maps with interest and that he would from time to time discuss it with the performing artists. In addition, he was confident that the map project would »not lack any good effects [...]«.

A few years after their meeting in Paris, Alexander von Humboldt (1769-1859) thanked Keferstein for a letter and the sending of »your so extremely instructive and important work«. He went on to write: »Since I had the pleasure of seeing you in Paris, you have not ceased to direct your activity toward the structures of Germany.« Humboldt promised to »contribute everywhere, to the best of my ability, to promote your work«. From his acquaintance with Humboldt, Keferstein had obviously not only promised to intercede with him in influential circles, but had also asked him to present copies of his works to the Prussian king and the crown prince. This »most kindly expressed wish«, however, »unfortunately does not allow my situation to be fulfilled directly, since iron laws of form [...] determine these broadcasts«. Keferstein was well aware and wanted to profit from the fact that Humboldt occasionally used his proximity to the Prussian royal house to support cultural and scientific concerns and to promote young talented artists and scientists.

The historical maps from the estate of the Halle geologist and mineralogist Christian Keferstein are now also available in the digital collections of the August Hermann Francke Study Center.

One year after his first work, Keferstein published another book on the »basaltic formations«, now based on his own observations in Saxony, Hesse, Bavaria and the Rhine regions, where he found »very clear evidence of their volcanicity«. At this time, shortly after Werner's death, the view of the Neptunian origin of basalt was still widely spread, but found fewer and fewer supporters in the scientific community.

The publication of this journal, the writing of the articles and the development of the maps occupied Keferstein for ten years. Sales problems and tensions with the publisher finally brought the ambitious project to a standstill after seven volumes with a total of 20 issues.

In his autobiography, Keferstein mainly described his work in geology in the first half of the 19th century. In doing so, he staged himself as an independent geologist who courageously opposed the prevailing views. However, he was largely denied the recognition he always hoped for from his colleagues. After 1840, Keferstein turned to other topics, also because of his advanced age, which no longer allowed for hiking, again with very peculiar theses. For example, he tried to prove the »Celticism of the Germanic peoples« by means of linguistic research and archaeological sources.

Educated dilettantes such as Keferstein were still no rarity in the first half of the 19th century and enriched geology with their research on its way to becoming a recognized science. Around 1850, however, they became obsolete, the times of career changers without a degree in natural sciences were over. Geology had established itself as an independent science at the universities.

Change

»Wir können also das Menschengeschlecht als eine Schar kühner, obwohl kleiner Riesen betrachten, die allmählich von den Bergen herabstiegen, die Erde zu unterjochen und das Klima mit ihrer schwachen Faust zu verändern. Wie weit sie es darin gebracht haben mögen, wird uns die Zukunft lehren.«

Johann Gottfried Herder (1744–1803)
Ideas on the philosophy of the history of mankind (1784–1791)

The exhibition ends with a leap in time to the present. It thus follows the annual theme of the Francke Foundations Berge versetzen. Über Tatkraft in Geschichte und Gegenwart. This motto is to be seen in a very positive light in view of the successful reconstruction of the foundations. In the context of this exhibition, we would like to reinterpret it, since mankind today is shaping and changing the earth in a way never seen before. At the latest since the beginning of the industrial revolution some 250 years ago, man has been intervening massively in the global ecosystem and influencing atmospheric, biological and geological processes to the benefit of his ever-growing needs. What has developed over millions of years can be irretrievably destroyed within a few generations. In view of the unimaginably long history of the earth, which was revealed in the 19th century, man was long considered an almost insignificant marginal phenomenon without much influence. Now he is once again moving right into the center of events. Therefore, not only geologists are discussing whether a new geological epoch of the earth has begun as a result of this profound human intervention: the Anthropocene - the age in which man fundamentally changed the earth. The final chapter of the exhibition is intended to provide food for thought.