Category Archives: History of Technology

Renaissance Science – XIV

In the previous episode we saw how the Renaissance rediscovery of Vitruvius’ De architectura influenced the development of architecture during the Renaissance and dissolved the boundary between the intellectual theoreticians and the practical artisans. However, as stated there Vitruvius was not just an architect, but was also an engineer and his Book X deals quite extensively with machines both civil and military. This had a massive influence on a new type of artisan the Renaissance artist-engineer and it is to these that we now turn our attention. 

Artist-engineers were very much a Northern Italian Renaissance phenomenon, but even earlier artists had been categorised as craftsmen or artisans and not as artists as we would understand the term. The occupation of artist-engineer was very much influenced by the popularity of Vitruvius’ De architectura. The most well-known Renaissance artist engineer is, of course, Leonardo da Vinci (1452–1519), but he was by no means unique, as he is often presented in popular accounts, but he stood at the end of a line of other artist-engineers, who are known to have influenced him. Here I will deal principally with those artisan artist-engineers, who dissolved the boundary between practice and theory by witing and circulating treatises on their work.

At the beginning of the line were the Florentine rival, goldsmiths Lorenzo Ghiberti (1378–1455) and Filippo Brunelleschi (1377–1446). In 1401 there was a competition to design the first set of new doors for the Florence Baptistery. Ghiberti and Brunelleschi were two of the seven artists on the short list. Ghiberti won the commission and set up a major engineering workshop to carry out the work. 

It took Ghiberti twenty-one years to complete the first set of doors featuring twenty New Testament Bible scenes, the four evangelists and four of the Church Fathers, but once finished they established his reputation, as a great Renaissance artist. In 1425 he was awarded a second commission for another set of doors, these featuring ten Old Testament scenes in realistic perspective presentation took another twenty-seven years. The second set of doors included portraits of both Ghiberti and his father Bartolomeo Ghiberti. 

Ghiberti self portrait from his second set of doors (modern copy Source: Wikimedia Commons

We don’t need to go into any great detail here about the doors or the other commissions that Ghiberti’s workshop finished.

Ghiberti’s second set of doors, known as the Gates of Paradise (modern copy) Source: Wikimedia Commons

What is much more relevant to our theme is his activities as an author. Although he was the artisan son of an artisan father, Ghiberti crossed the medieval boundary between theory and practice with his Commentarii, a thesis on the history of art, written in Italian. He drew on various sources from antiquity including the first century BCE illustrated Greek text on machines by Athenaeus Mechanicus and Pliny’s Naturalis Historia, a text much discussed by the Renaissance Humanists, but his major source was Vitruvius’ De architectura. Ghiberti died without finishing his Commentarii and it was never published. However, many important Renaissance artist, such as Donatello and Paolo Uccello, served their apprenticeships in his workshop, so his influence on future generations was very large.

One probable graduate of Ghiberti’s workshop was Antonio Averlino (c. 1400–c. 1469) known as Filarete, a sculptor and architect. 



Filarete, Self-portrait medal, obverse, c. 1460, bronze. London, V & A

 Between 1461 and 1464, he wrote a vernacular volume on architecture in twenty-five books, his illustrated Trattato di Architettura, which circulated widely in manuscript. Central to his theory of architecture was the Vitruvian ideal of practice combined with theory. The most significant part of his book was his design for Sforzinda an ideal city named after his patron Francesco Sforza (1401–1466). This was the first of several ideal cities, which became a feature of the Renaissance. It is thought that his inspiration came from the works of Plato and his knowledge of this came from his friend at the Sforza court, the humanist scholar and philologist Francesco da Tolentino (1398–1481) known as Filelfo. Once again, we have, as in the last episode, a cooperation across the old boundaries between a scholar and an artisan.

Filarete Sforzinda

Filippo Brunelleschi poses a different problem. Like Ghiberti trained as a goldsmith, he went on to become the epitome of a Renaissance Vitruvian architect. However, there is no direct evidence that connects him with De architectura or its author. There is no direct evidence that connects him with anything except for the products of his life’s work, most notably the dome of the Santa Maria del Fiori cathedral in Florence. He is also renowned as the inventor or discoverer of the mathematical principles of linear perspective, as explained in episode seven of this series. This links him indirectly to Vitruvius, as some authors insist that he only rediscovered linear perspective, quoting Book 7 of De architectura, where Vitruvius describes the use of some form of perspective on the ancient Greek theatre flats. 

Filippo Brunelleschi in an anonymous portrait of the 2nd half of the 15th century (Louvre, Paris) Source: Wikimedia Commons

More importantly, Brunelleschi, as an architect, not only designed and supervised the construction of the buildings that he was commissioned to build but also devised and constructed the machines that he needed on his building sites to facilitate those constructions. For his work on the Santa Maria dome, for example he designed a crane to lift the building materials up to the top of the cathedral.

Brunelleschi’s revolving crane

A drawing of that crane can be found in Leonardo’s manuscripts. He was also granted a patent by the ruling council of Florence for the design of a ship to transport heavy loads of stone on rivers and canals.

Reproduction of Brunelleschi’s patent boat Source: Wikimedia Commons

Brunelleschi was also like, Vitruvius, a successful hydraulic engineer. It is hard to believe that he wasn’t influenced by De architectura.

There is no doubt about the Vitruvian influence of our next artist-engineer, Mariano di Jacopo (1382–c. 1453) known as Taccola (the jackdaw), who, as I explained in an earlier post on that Renaissance iconic figure, included a Vitruvian Man in his drawings. Taccola, who is known to have worked as a sculptor, superintendent of roads and hydraulic engineer, was from Sienna. He met and talked with Brunelleschi, one of the few people known to have done so. 

Taccola produced two annotated manuscripts the four books of De ingeneis, written between 1419 and 1433, and De machnis issued in 1449, which was partially an improved version of his De ingeneis.


ResearchGate
Jacopo Mariano Taccola, De ingeneis, Book I. Codex Latinus 197,..

Both manuscripts contain numerous illustrations of machines for hydraulic engineering, milling (and mills were one of the most important types of machines in medieval and Renaissance culture), construction and military machinery, all topics covered by Vitruvius.

First European depiction of a piston pump by Taccola, c.1450 Source: Wikimedia Commons

His manuscripts also some of Brunelleschi’s construction machines. Taccola is in one sense a transitional figure as his representations, of three-dimensional machines, often use medieval drawing conventions rather than Brunelleschi’s recently discovered linear perspective. 

Taccola’s works were never printed but copies of his manuscripts are known to have circulated widely during his lifetime and to have been highly influential. After his death his influence waned as his work was superceded by the more advance work of Francesco di Giorgio Martini and Leonardo da Vinci both of whom were heavily influenced by Taccola.

Francesco di Giorgio Martini (1439–1501) was, like Taccola, from Siena and was an architect, engineer, painter, sculptor, and writer.

His Vitruvian influence is very obvious in his work, as also the influence of Taccola. Francesco worked for much of his life on an Italian translation of Vitruvius’ De architectura, which he never published. Like Filarete he wrote an architectural treatise Trattato di archtettura, ingegneria e arte militare, worked on over decades and finished sometime after 1482. Many of his machines are taken from Taccola’s manuscripts. As can be seen from the title, it continues the Vitruvian tradition. Like Filarete’s volume it contains a design for an ideal town. Probably inspired by Sulpizio’s first printed edition of De architectura and Alberti’s De re aedificatoria, he produced a new edition of his own book known as Trattato II. 

Edificij et machine, Martini, Francesco di Giorgio, 1439-1501, brown ink and wash, ca. 1475-ca. 1480, The volume comprises 103 drawings by Francesco di Giorgio Martini and his assistants, featuring machines and devices for lifting columns and other heavy weights, schemes for transporting water, and mechanisms for milling and moving boats. There are also a few drawings showing how people could walk or float on water standing on inflatable containers and using an oar to propel themselves. PUBLICATIONxINxGERxSUIxAUTxONLY Copyright: LCD2_180906_23583

Both Taccola and Francesco are known to have influenced the most famous of the Renaissance artist-engineers, Leonardo da Vinci. As well as the obvious direct influence of Vitruvius, many of the machines illustrated in Leonardo’s manuscripts are taken from the work of Brunelleschi, Taccola and Francesco di Giorgio. As an apprentice, Leonardo had worked on the final phase of Brunelleschi’s dome for the Santa Maria Cathedral, and he took the opportunity to study Brunelleschi’s building site machines and scaffolding. He owned copies of the manuscripts of both Taccola and Francesco, the latter of which he annotated heavily. Leonardo, as is well known, wrote reams of annotated manuscripts on his machines but never published any of them.

Watter wheel, just one of Leonardo’s hundreds of drawings of machines Source

All of the artist-engineers that I have briefly sketched here are examples of artisans who crossed over or better dissolved the boundaries between theoretical and practical knowledge. They are also, so to speak, the stars of a much larger and widespread group of Renaissance artist-engineers, whose influence spread throughout the Renaissance, changing and elevating the status of the skilled artisan.  

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Filed under Book History, History of Technology, Renaissance Science

Renaissance Science – XIII

As already explained in the fourth episode of this series, the Humanist Renaissance was characterised by a reference for classical literature, mostly Roman, recovered from original Latin manuscripts and not filtered and distorted through repeated translations on their way from Latin into Arabic and back into Latin. It was also a movement that praised a return to classical Latin, away from the, as they saw it, barbaric medieval Latin. In the fifth episode we also saw that, what I am calling, Renaissance science was characterised by a break down of the division that had existed between theoretical book knowledge as taught on the medieval universities and the empirical, practical knowledge of the artisans. As also pointed there this was not so much a breaking down of boundaries or a crossover between the two fields of knowledge as a meld between the two types of knowledge that would over the next two and a half centuries lead to the modern concept of knowledge or science.

One rediscovered classical Latin text that very much filled the first criterium, which at the same time played a major role in the second was De architectura libri decem (Ten Books on Architecture) by the Roman architect and civil and military engineer Marcus Vitruvius Pollio (c.80-70–died after 15 BCE), who is usually referred to simply as Vitruvius and there are doubts about the other two names that are ascribed to him. 

From the start we run into problems about the standard story that the manuscript was rediscovered by the Tuscan, humanist scholar Poggio Bracciolini (1380–1459) in the library of Saint Gall Abbey in 1416, as related by Leon Battista Alberti (1404–1472) in his own architecture treatise De re aedificatoria (1452), which was modelled on Vitruvius’ tome. In reality, De architectura had never been lost during the Middle Ages; there are about ninety surviving medieval manuscripts of the book.

Manuscript of Vitruvius; parchment dating from about 1390 Source: Wikimedia Commons

The oldest was made during the Carolingian Renaissance in the early nineth century. Alcuin of York was consulted on the technical terms in the text. During the Middle Ages many leading scholars including Hermann of Reichenau (1013–1054), a central figure of the Ottonian Renaissance, and both Albertus Magnus (c. 1200– 1280) and Thomas Aquinas (1225–1274), who laid the foundations of medieval Aristotelian philosophy, read the text, and commented on it. 

However, although well-known it had little impact on architecture in the medieval period. The great medieval cathedrals and castle were built by master masons, whose knowledge was practical artisanal knowledge passed on by word of mouth from master to apprentice. This changed with Poggio’ rediscovery of Vitruvius’ work and the concept of the theoretical and practical architect began to emerge.

Before we turn to the impact of De architectura in the Renaissance we first need to look at the book and its author. Very little is known about Vitruvius, as already stated above, the other names attributed to him are based on speculation, most of what we do know is pieced together from the book itself. Vitruvius was a military engineer under Gaius Julius Caesar (100–44 BCE) and apparently received a pension from Octavian (63 BCE–14 CE), the later Caesar Augustus, to whom the book is dedicated. The book was written around twenty BCE. Vitruvius wrote it because he believed in making knowledge public and available to all, unlike those artisans, who kept their knowledge secret.

The ten books are organised as follows:

  1. Town planning, architecture or civil engineering in general and the qualification required by an architect or civil engineer
  2. Building materials
  3. Temples and the orders of architecture
  4. As book 3
  5. Civil buildings
  6. Domestic buildings
  7. Pavements and decorative plasterwork
  8. Water supplies and aqueducts
  9. The scientific side of architecture – geometry, measurement, astronomy, sundials
  10. Machines, use and construction – siege engines, water mills, drainage machines, technology, hoisting, pneumatics

In terms of its reception and influence during the Renaissance the most important aspect is Vitruvius’ insistence that architecture requires both ratiocinatio and fabrica, that is reasoning or theory, and practice or construction. This Vitruvian philosophy of architecture took architecture out of the exclusive control of the master mason and into the hands of the theoretical scholars in union with the artisans. This move was also motivated by the humanist drive to study archaeologically the Roman remains in Rome the Eternal City. Vitruvius provided a guide to understanding the Roman architecture, which would become the model for the construction of new buildings. 

But for it to become influential Vitruvius’s text first had to become widely available. The first printed Latin edition was edited by the humanist scholar Fra. Giovanni Sulpizio da Veroli (fl. c. 1470–1490) and published in 1486 with a second edition in 1495 or 1496.

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The first printed edition had no illustrations. Fra. Giovanni Giocondo da Verona (c. 1433–1515) produced the first edition with woodcut illustrations, published in Venice in 1511. A second improved edition was published in Florence in 1521. 

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In order for De architectura to reach artisans it needed to be translated into the vernacular, as most of them couldn’t read Latin. This process began in Italy and during the sixteenth century spread throughout Europe. The process started already before De architectura appeared in print. As mentioned above Alberti’s De re aedificatoria (On the Art of Buildings), not a translation of De architectura but a book strongly modelled on it appeared in Latin in print in 1452.

Source: Wikimedia Commons

The first Italian edition appeared in 1486 A second Italian edition, by the humanist mathematician Cosimo Bartoli (1503-1572), which became the standard edition, appeared in 1550. Alberti was very prominent in Renaissance culture and very widely read. His influence can be measured by the fact that a collective bilingual, English/Italian, edition of his works on architecture, painting and sculpture was published as late as 1726. 

The first Italian edition of De architectura with new illustration and added commentary by Cesare Cesariano (1475-1543) was published at Como in 1521.

1521 Italian edition title page Source
1521 Italian edition

A plagiarised version was published in Venice in 1524. The first French edition, translated by Jean Martin (died 1553), which is said to contain many errors, was published in Paris in 1547.

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The first German edition was translated by Walther Hermann Ryff (c. 1500–1548). As far as can be determined, it appears the Ryff was an apothecary but work mostly as what today would probably be described as a hack. He published as editor, translator, adapter, and compiler a large number of books, around 40, over a wide range of topics, although the majority were in some sense medical, and was seemingly very successful. He was often accused of plagiarism. The physician and botanist, Leonhart Fuchs (1501–1566) described him as an “extremely brazen, careless, fraudulent author.” Apart from his medical works, Ryff obviously had a strong interest in architecture. He edited and published a Latin edition of De architectura in Strasbourg in 1543. This was followed by a commentary on De architectura in German, Der furnembsten, notwendigsten, der gantzen Architectur angehörigen Mathematischen vnd Mechanischen künst, eygentlicher bericht, vnd vast klare, verstendliche vnterrichtung, zu rechtem verstandt der lehr Vitruuij, in drey furneme Bücher abgetheilet (The most distinguished, necessary, mathematical and mechanical arts belonging to the entire architecture, actual report and clear, understandable instruction of the teachings of Vitruvius shared in three distinguished books), published by Johannes Petreius, the leading European scientific publisher of the period, in Nürnberg in 1547. For obvious reasons this is usually simply referred to as Architektur. This was obviously a product of the German translation of De architectura, which Petreius had commissioned Ryff to produce and, which he published in Nürnberg in 1548 under the title, Vitruvius Teutsch. Nemlichen des aller namhafftigisten vñ hocherfahrnesten römischen Architecti vnd kunstreichen Werck zehn Bücher von der Architectur und künstlichem Bawen… (Vitruvius in German…).

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We return now to Italy and the story of the stone mason, Andrea di Pietro della Gondola, born in Padua in 1508. Having served his apprenticeship, he worked as a stone mason until he was thirty years old. In 1538–39, he was employed to rebuild the villa of the humanist poet and scholar, Gian Giorgio Trissino (1478–1550) to rebuild his villa in Cricoli.

Gian Giorgio Trissino, portrayed in 1510 by Vincenzo Catena Source: Wikimedia Commons
Villa Trissino Source: Wikimedia Commons

Trissino ran a small private learned academy for young gentlemen in his renovated villa and apparently, having taken a shine to the young stone mason invited him to become a member. Andrea accepted the offer and Trissino renamed him Palladio.

Portrait of Palladio by Alessandro Maganza Source: Wikimedia Commons

The two became friends and colleagues, and Trissino, who was deeply interested in classical architecture and Vitruvius took the newly christened Palladio with him on trips to Rome to study the Roman ruins. Palladio became an architect in 1540 and became a specialist for designing and building neo-classical, Palladian, villas. 

Villa Barbaro begun 1557 Source: Wikimedia Commons

Trissino died in 1550 but Palladio acquired a new patron, Daniele Barbaro (1514–1570), a member of one of the most prominent and influential aristocratical families of Venice.

Daniele Barbaro by Paolo Veronese (the book in the painting is Barbaro’s translation of De architectura)

Daniele Barbaro studied philosophy, mathematics, and optics at the University of Padua. He was a diplomat and architect, who like Trissino, before him, accompanied Palladio on expeditions to study Roman architecture. In 1556, Barbaro published a new Italian translation of De architectura with an extended commentary, Dieci libri dell’architettura di M. Vitruvio.

I dieci libri dell’architettura di M. Vitruvio tradutti et commentati da monsignor Barbaro eletto patriarca d’aquileggia 1556 Images by Palladio Source

In 1567, he, simultaneously published, a revised Italian and a Latin edition entitled M. Vitruvii de architectura. The illustrations for Barbaro’s editions were provided by Palladio. Barbaro provided the best, to date, explanations of much of the technical terminology in De architectura, also acknowledging Palladio’s theoretical contributions to the work.

Palladio had become one of the most important and influential architects in the whole of Europe, designing many villas, palaces, and churches. He also became an influential author publishing L’Antichida di Roma (The Antiquities of Rome) in 1554,

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and I quattro libri dell’architettura (The Four Books of Architecture) in 1570, which was heavily influenced by Vitruvius. His books were translated into many different languages and went through many editions right down into the eighteenth and nineteenth centuries. His work inspired leading architects in France and Germany.

Title page from 1642 edition Source: Wikimedia Commons

Up till now we have said nothing about England, which as usual lagged behind the continent in things mathematical, although in the second half of the sixteenth century both Leonard Digges and John Dee, of the so-called English school of mathematics, counted architecture under the mathematical disciplines. In 1563 John Shute (died 1563) included Vitruvian elements in his The First and Chief Grounds of Architecture.

John Shute The First and Chief Grounds of Architecture.

Inigo Jones (1573–1652) was born into a Welsh speaking family in Smithfield, London. There is minimal evidence that he was an apprentice joiner but at some point, before 1603 he acquired a rich patron, who impressed by his sketches, sent him to Italy to study drawing in Italy.

Inigo Jones by Anthony van Dyck

In a second visit to Italy in 1606 he came under the influence of Sir Henry Wotton (1568–1639) the English ambassador to Venice.

Henry Wotton artist unknown Source: Wikimedia Commons

Wotton was interested in astronomy, and it was he, who sent two copies of Galileo’s Sidereus Nuncius (1610) to London on the day it was published. Wotton convinced Jones to learn Italian and introduced him to Palladio’s I quattro libri dell’architettura. Jones’ copy of the book has marginalia that references Wotton. In 1624, Wotton published The Elements of Architecture a loose translation of De architectura into English. The first proper translation appeared only in 1771. 

19th century reprint Source

Inigo Jones introduced the Vitruvian–Palladian architecture into England and became the most influential architect in the country, becoming Surveyor of the King’s Works.

The Queen’s House in Greenwich designed and built by Inigo Jones Source: Wikimedia Commons

His career was ended with the outbreak of the English Civil War in 1642. England’s most famous architect Christopher Wren (1632–1723), a mathematician and astronomer turned architect stood in a line with Vitruvius, Palladio, and Jones. It is very clear that the humanist rediscovery and promotion of De architectura had a massive influence on the development of architecture in Europe in the sixteenth and seventeenth centuries, in the process dissolving the boundaries between the theoretical intellectuals and the practical artisans. 

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Filed under History of Mathematics, History of Technology, Renaissance Science

The deviser of the King’s horologes

There can’t be many Renaissance mathematici, whose existence was ennobled by a personal portrait by the master of the Renaissance portraits, Hans Holbein the younger. In fact, I only know of one, the German mathematicus, Nicolas Kratzer.

Nicolas Kratzer Portrait by Hans Holbein the younger

One might be excused for thinking that having received this singular honour that Kratzer had, in his lifetime, achieved something truly spectacular in the world of the Renaissance mathematical disciplines; however, almost the opposite is true. Kratzer appears to have produced nothing of any significance, was merely the designer and maker of sundials, and an elementary maths teacher, who was only portrayed by Holbein, because for a time they shared the same employers and were apparently mates. 

So, who was Kratzer and how did he and Holbein become mates? Here we find a common problem with minor scientific figures in the Renaissance, there are no biographies, no handy archives giving extensive details of his life. All we have are a few, often vague, sometimes contradictory, traces in the proverbial sands of time from which historians have attempted to reconstruct at least a bare outline of his existence. 

Kratzer was born in 1487 in Munich, the son of a saw-smith and it is probably that he learnt his metal working skills, as an instrument maker, from his father. He matriculated at the University of Köln 18 November 1506 and graduated BA 14 June 1509. He moved onto the University of Wittenberg, famous as the university of Martin Luther. However, this was before the Reformation and Wittenberg, a young university first founded in 1502, was then still Catholic. We now lose track of Kratzer, who is presumed to have then worked as an instrument maker. Sometime in the next years, probably in 1517, he copied some astronomical manuscripts at the Carthusian monastery of Maurbach, near Vienna. 

In January 1517, Pieter Gillis (1486–1533) wrote to his erstwhile teacher Erasmus (1466–1536) that the skilled mathematician Kratzer was on his way with astrolabes and spheres, and a Greek book.

HOLBEIN, Hans the Younger (b. 1497, Augsburg, d. 1543, London) Portrait of Erasmus of Rotterdam 1523 Wood, 76 x 51 cm National Gallery, London

This firmly places Kratzer in the circle of humanist scholars, most famously Erasmus and Thomas More (1478–1535) author of Utopia, who founded the English Renaissance on the court of Henry VIII (1491–1547). Holbein was also a member of this circle. Erasmus and Holbein had earlier both worked for the printer/publisher collective of Petri-Froben-Amerbach in Basel. Erasmus as a copyeditor and Holbein as an illustrator. Holbein produced the illustrations for Erasmus’ In Praise of Folly (written 1509, published by Froben 1511)

Holbein’s witty marginal drawing of Folly (1515), in the first edition, a copy owned by Erasmus himself

Kratzer entered England either at the end of 1517 or the beginning of 1518. His first identifiable employment was in the household of Thomas More as maths teacher for a tutorial group that included More’s children. It can be assumed that it was here that he got to know Holbein, who was also employed by More. 

Thomas More Portrait by Hans Holbein 1527

For his portraits, Holbein produced very accurate complete sketches on paper first, which he then transferred geometrically to his prepared wooden panels to paint them. Around 1527, Holbein painted a group portrait of the More family that is no longer extant, but the sketch is. The figures in the sketch are identified in writing and the handwriting has been identified as Kratzer’s. 

Like Holbein, Kratzer moved from More’s household to the court of Henry VIII, where he listed in the court accounts as the king’s astronomer with an income of £5 a quarter in 1529 and 1531. It is not very clear when he entered the King’s service but in 1520 Cuthbert Tunstall (1474–1559), later Prince-Bishop of Durham, wrote in a letter:

Met at Antwerp with [Nicolas Kratzer], an Almayn [German], devisor of the King’s horologes, who said the King had given him leave to be absent for a time.

Both Tunstall and Kratzer were probably in Antwerp for the coronation of Charles V (1500–1558) as King of Germany, which took place in Aachen. There are hints that Kratzer was there to negotiate with members of the German court on Henry’s behalf. Albrecht Dürer (1471–1528) was also in the Netherlands; he was hoping that Charles would continue the pension granted to him by Maximilian I, who had died in 1519. Dürer and Kratzer met in the house of Erasmus and Kratzer was present as Dürer sketched a portrait of Erasmus. He also drew a silver point portrait of Kratzer, which no longer exists. 

 

Dürer sketch of Erasmus 1520
Dürer engraved portrait of Erasmus based on 1520 sketch finished in 1526. Erasmus reportedly didn’t like the portrait

Back in England Kratzer spent some time lecturing on mathematical topics at Oxford University during the 1520s. Here once again the reports are confused and contradictory. Some sources say he was there at the behest of the King, others that he was there in the service of Cardinal Wolsey. There are later claims that Kratzer was appointed a fellow of Corpus Christi College, but the college records do not confirm this. However, it is from the Oxford records that we know of Kratzer’s studies in Köln and Wittenberg, as he was incepted in Oxford as BA and MA, on the strength of his qualifications from the German institutions, in the spring of 1523. 

During his time in Oxford, he is known to have erected two standing sundials in the college grounds, one of which bore an anti-Lutheran inscription.

Drawing of Kratzer’s sundial made for the garden of Corpus Christi College Oxford

Neither dial exists any longer and the only dial of his still there is a portable brass dial in the Oxford History of Science Museum, which is engraved with a cardinal’s hat on both side, which suggests it was made for Wolsey.

Kratzer polyhedral sundial presumably made for Cardinal Wolsey Museum for the History of Science Oxford

On 24 October 1524 Kratzer wrote the following to Dürer in Nürnberg

Dear Master Albert, I pray you to draw for me a model of the instrument that you saw at Herr Pirckheimer’s by which distances can be measured, and of which you spoke to me at Andarf [Antwerp], or that you will ask Herr Pirckheimer to send me a description of the said instrument… Also I desire to know what you ask for copies of all your prints, and if there is anything new at Nuremberg in my craft. I hear that our Hans, the astronomer, is dead. I wish you to write and tell me what he has left behind him, and about Stabius, what has become of his instruments and his blocks. Greet in my name Herr Pirckheimer. I hope shortly to make a map of England which is a great country, and was not known to Ptolemy; Herr Pirckheimer will be glad to see it. All who have written of it hitherto have only seen a small part of England, no more… I beg of you to send me the likeness of Stabius, fashioned to represent St. Kolman, and cut in wood…

Herr Pirckheimer is Willibald Pirckheimer (1470–1530), who was a lawyer, soldier, politician, and Renaissance humanist, who produced a new translation of Ptolemaeus’ Geographia from Greek into Latin.

Engraved portrait of Willibald Pirckheimer Dürer 1524

He was Dürer’s life-long friend, (they were born in the same house), patron and probably lover.  He was at the centre of the so-called Pirckheimer circle, a group of mostly mathematical humanists that included “Hans the astronomer, who was Johannes Werner (1468–1522), mathematician, astronomer, astrologer, geographer,

Johannes Werner artist unknown

and cartographer and Johannes “Stabius” (c.1468–1522) mathematician, astronomer, astrologer, and cartographer.

Johannes Stabius portrait by Dürer

Werner was almost certainly Dürer’s maths teacher and Stabius worked together with Dürer on various projects including his star maps. The two are perhaps best known for the Werner-Stabius heart shaped map projection. 

Dürer replied to Kratzer 5 December 1524 saying that Pirckheimer was having the required instrument made for Kratzer and that the papers and instruments of Werner and Stabius had been dispersed.

Here it should be noted that Dürer, in his maths bookUnderweysung der Messung mit dem Zirkel und Richtscheyt (Instruction in Measurement with Compass and Straightedge), published the first printed instructions in German on how to construct and orientate sundials. The drawing of one sundial in the book bears a very strong resemblance to the polyhedral sundial that Kratzer made for Cardinal Wolsey and presumably Kratzer was the original source of this illustration. 

Dürer drawing of a sundial

Kratzer is certainly the source of the mathematical instruments displayed on the top shelf of Holbein’s most famous painting the Ambassadors, as several of them are also to be seen in Holbein’s portrait of Kratzer.

in’s The AmbassadorsHolbe

Renaissance Mathematicus friend and guest blogger, Karl Galle, recently made me aware of a possible/probable indirect connection between Kratzer and Nicolas Copernicus (1473–1543). Georg Joachim Rheticus (1514–1574) relates that Copernicus’ best friend Tiedemann Giese (1480–1550) possessed his own astronomical instruments including a portable sundial sent to him from England. This was almost certainly sent to him by his brother Georg Giese (1497–1562) a prominent Hanseatic merchant trader, who lived in the Steelyard, the Hansa League depot in London, during the 1520s and 30s.

London’s Steelyard

He was one of a number of Hanseatic merchants, whose portraits were painted by Holbein, so it is more than likely that the sundial was one made by Kratzer. 

Georg Giese portrait by Hans Holbein 1532

Sometime after 1530, Kratzer fades into the background with only occasional references to his activities. After 1550, even these ceased, so it is assumed that he had died around this time. In the first half of the sixteenth century England lagged behind mainland Europe in the mathematical disciplines including instrument making, so it is a natural assumption that Kratzer with his continental knowledge was a welcome guest in the Renaissance humanist circles of the English court, as was his younger contemporary, the Flemish engraver and instrument maker, Thomas Gemini (1510–1562). Lacking homegrown skilled instrument makers, the English welcomed foreign talent and Kratzer was one who benefited from this. 

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Christmas Trilogy 2020 Part 2: Charles brightens up the theatre

There is a strong tendency in the present to view Charles Babbage as a one trick pony i.e., Babbage the computer pioneer. In reality he was a true polymath whose intellectual activities covered a very wide spectrum.

Already as a student at Cambridge, he agitated for major curriculum reform in the mathematics taught and practiced in Britain. He also produced some first class cutting edge mathematics, much of which for some reason he never published. His interest in automation stretched way beyond his computing engines and after extensive research on automations in industry, both throughout Europe and in Britain, he wrote and published a book on the organisation of industrial production, On the Economy of Machinery and Manufactures (1832), which became a highly influential bestseller, influencing the work of both John Stuart Mill and Karl Marx. He was a leader in a campaign to improve the standard of science research in Britain, largely aimed at what he saw as the moribund Royal society, which resulted in his Reflections on the Decline of Science and some of its Causes (1830). As part of this campaign, he was a leading figure in the establishment of the British Association for the Advancement of Science (BAAS).

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Engraving of Charles Babbage dated 1833 Source: Wikimedia Commons 

His achievements were not confined to purely intellectual activities, he was also an assiduous inventor of mechanical devices and improvement, well outside of his proto computers. For example, he designed and had constructed a four wheeled light carriage for one of his extensive tours of Europe. It was so designed that he could sleep on board and had drawers large enough to stow frock coats and technical plans without folding, as well as a small on board kitchen. However, it is his activities in practical optics that interest me here, in particular his foray into early theatre lighting, which I found fascinating, having, for several years in my youth, been a lighting technician both in theatre and live music.  

An ophthalmoscope is a medical instrument designed to make it possible to observe the interior of the eye by means of a beam of light. The invention of the ophthalmoscope is traditionally attributed to Hermann von Helmholtz in 1851. However, it would appear that Babbage preceded him by four years.

Charles Babbage, the mathematic genius and inventor of what many consider to be the forerunner of today’s computer, his analytical machine, was the first to construct an instrument for looking into the eye. He did this in 1847 but when showing it to the eminent ophthalmologist Thomas Wharton Jones he was unable to obtain an image with it and, thus discouraged, did not proceed further. Little did he know that his instrument would have worked if a minus lens of about 4 or 5 dioptres had been inserted between the observer’s eye and the back of the plano mirror from which two or three holes had been scraped. Some seven years later it was his design and not that of Helmholtz which had been adopted.

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The image shows a reconstruction of Babbage’s ophthalmoscope, c. 1847. No actual example survives but this replica was made for the Science Museum in 2003, based upon Wharton Jones’ written description.

Dr. Helmholtz, of Konigsberg, has the merit of specially inventing the ophthalmoscope. It is but justice that I should here state, however, that seven years ago Mr. Babbage showed me the model of an instrument which he had contrived for the purpose of looking into the interior of the eye. It consisted of a bit of plain mirror, with the silvering scraped off at two or three small spots in the middle, fixed within a tube at such an angle that the rays of light falling on it through an opening in the side of the tube, were reflected into the eye to be observed, and to which the one end of the tube was directed. The observer looked through the clear spots of the mirror from the other end. This ophthalmoscope of Mr Babbage, we shall see, is in principle essentially the same as those of Epkens and Donders, of Coccius and of Meyerstein, which themselves are modifications of Helmhotlz’s.

         Wharton-Jones, T., 1854, ‘Report on the Ophthalmoscope’, Chronicle of Medical Science (October 1854).

Around the same time as he built his ophthalmoscope, Babbage designed and built a mechanical, clockwork, programmable, self-occulting, signalling lamp to aid ship to ship and ship to shore communications. He was disappointed that the British marine fleets showed no interest in his invention, but the Russian navy used it against the British during the Crimean War. During the Great Exhibition of 1851, in which Babbage played a central role, he set his signal lamp in the window of his house in the evenings and people passing by would drop in their visiting card with the signalled number written on them. Babbage’s occulting lights were later used in lighthouses in various parts of the world starting in the USA.

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Babbage’s mechanical, clockwork, programmable, self-occulting, signalling lamp mechanism

Babbage was a theatre goer and during his phase of light experiments and invention he undertook an interesting project in theatre lighting. During the Renaissance, theatres, such as Shakespeare’s Globe, were open air arenas and performances took place in daylight. Later closed theatre and opera house were lit with chandeliers with the cut glass or crystal prisms dispersing the candlelight in all directions. Of course, the large number of candles needed caused much smoke and the dripping wax was a real problem. By the early nineteenth century theatres were illuminated with gas lamps.

One day during a theatre visit, Babbage noticed that during a moonlit scene the white bonnet of his companion had a pink taint and wondered about the possibility of using coloured light in theatre. He began a serious of interesting experiments with the then comparatively new limelight.

Limelight is an intense illumination created when an oxyhydrogen flame is directed at a cylinder of quicklime (calcium oxide). Quicklime can be heated to 2,572°C before melting and the light is produced by a combination of incandescence (the emission of electromagnetic radiation such as visible light e.g., red hot steel) and candoluminescence a form of radiation first observed and investigated in the early nineteenth century.

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Diagram of a limelight burner Source: Wikimedia Commons

As with many inventions the oxyhydrogen blowpipe has many fathers and was first developed in the late eighteenth and early nineteenth centuries by Jean-Baptiste-Gaspard Bochart de Saron (1730–1794), Edward Daniel Clarke (1769–1822) and Robert Hare (1781–1858) all of whose work followed out of the pneumatic discoveries of Carl Wilhelm Scheele (1742–1786), Joseph Priestly (1733–1804), who both discovered oxygen, and Henry Cavendish (1731–1810), who discovered hydrogen.

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Nineteenth century bellows-operated oxy-hydrogen blowpipe, including two different types of flashback arrestor John Griffen – A Practical Treatise on the Use of the Blowpipe, 1827 Source: Wikimedia Commons

The first to discover and experiment with limelight was the English chemist Goldsworthy Gurney (1792–1875)

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Goldsworthy Gurney Source: Wikimedia Commons

but it was the Scottish engineer Thomas Drummond (1797–1840) who, having seen it demonstrated by Michael Faraday (1791–1867),  first exploited its potential as a light source. Drummond built a practical working light in 1826, which he then used as a signal lamp in trigonometrical surveying. The light was bright enough to be seen at a distance of 68 miles by sunlight. Drummond’s application was so successful that limelight was also known as Drummond light and he was falsely credited with its discovery, instead of Gurney.

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Thomas Drummond by Henry William Pickersgill. The original picture is in the National gallery of Ireland Source: Wikimedia Commons

The earliest know public performance illuminated with limelight was an outdoor juggling performance by the magician Ching Lau Lauro (real name unknown) Herne Bay Pier in Kent in 1836. It was first used in theatre lighting in Covent Garden Theatre in 1837. By the 1860s and 1870s limelight was used worldwide in theatres and operas, used to highlight solo performers in the same way as modern spotlights, hence the expression, standing in the limelight. By the end of the nineteenth century, it had been largely replaced by electrical, carbon arc lighting.

 Babbage wanted to take the process one step further and use limelight not just as a very bright white light, but to introduce colour into theatre lighting. Babbage began to experiment with glass cells constructed out of two parallel sheets of glass and filled with solutions of various metal salts, such as chrome and copper. His experiment proved very successful and he developed coloured, limelight spots. Babbage now developed a dance scenario to display his new invention. He proposed replacing the stage footlights with four limelight projectors in the colours red, blue, yellow and purple. His imagined piece had four groups of dancers dressed in white, each of which entered the stage dancing in one of the four pools of light. Dancers springing from one pool of light into another would change colour. Gradually the apertures would widen with the lights crossing each other producing a rainbow of colours through which the dancers would circle. Babbage went on to develop a dramaturgy with dioramas telling an allegorical story.

Babbage discussed his project with Benjamin Lumley, the manager of the Italian Opera House (now Her Majesty’s Theatre) and arranged a demonstration of his new lights. The demonstration took place in the theatre with a smaller group of dancers, and it was apparently a great success. However, because of the fire risk he had two fire engines and their crews on standby during his demonstration and although impressed, Lumley declined a real performance with an audience because of the fire risk. Babbage didn’t develop the idea further.

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Portrait of Benjamin Lumley by D’Orsay Source: Wikimedia Commons

As a onetime theatre lighting technician and a historian of science, I would would quite like the idea of staging a modern version of Babbage’s little dance fantasy. I would also like to draw this episode in his life to the attention of all the Ada Lovelace acolytes, who are firmly of the opinion that Babbage was only capable of thinking about mathematics and therefore the imaginative flights of fancy in the Analytical Engine memoir notes must be entirely the work of Lady King.

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The emergence of modern astronomy – a complex mosaic: Part LI

 

By the middle of the nineteenth century there was no doubt that the Earth rotated on its own axis, but there was still no direct empirical evidence that it did so. There was the indirect evidence provided by the Newton-Huygens theory of the shape of the Earth that had been measured in the middle of the eighteenth century. There was also the astronomical evidence that the axial rotation of the other known solar system planets had been observed and their periods of rotation measured; why should the Earth be an exception? There was also the fact that it was now known that the stars were by no means equidistant from the Earth on some sort of fixed sphere but distributed throughout deep space at varying distances. This completely destroyed the concept that it was the stars that rotated around the Earth once every twenty-four rather than the Earth rotating on its axis. All of this left no doubt in the minds of astronomers that the Earth the Earth had diurnal rotation i.e., rotated on its axis but directly measurable empirical evidence of this had still not been demonstrated.

From the beginning of his own endeavours, Galileo had been desperate to find such empirical evidence and produced his ill-fated theory of the tides in a surprisingly blind attempt to deliver such proof. This being the case it’s more than somewhat ironic that when that empirical evidence was finally demonstrated it was something that would have been well within Galileo’s grasp, as it was the humble pendulum that delivered the goods and Galileo had been one of the first to investigate the pendulum.

From the very beginning, as the heliocentric system became a serious candidate as a model for the solar system, astronomers began to discuss the problems surrounding projectiles in flight or objects falling to the Earth. If the Earth had diurnal rotation would the projectile fly in a straight line or veer slightly to the side relative to the rotating Earth. Would a falling object hit the Earth exactly perpendicular to its starting point or slightly to one side, the rotating Earth having moved on? The answer to both questions is in fact slightly to the side and not straight, a phenomenon now known as the Coriolis effect produced by the Coriolis force, named after the French mathematician and engineer Gaspard-Gustave de Coriolis (1792–1843), who as is often the case, didn’t hypothesise or discover it first. A good example of Stigler’s law of eponymy, which states that no scientific discovery is named after its original discoverer.

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Gaspard-Gustave de Coriolis. Source: Wikimedia Commons

As we saw in an earlier episode of this series, Giovanni Battista Riccioli (1594–1671) actually hypothesised, in his Almagustum Novum, that if the Earth had diurnal rotation then the Coriolis effect must exist and be detectable. Having failed to detect it he then concluded logically, but falsely that the Earth does not have diurnal rotation.

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Illustration from Riccioli’s 1651 New Almagest showing the effect a rotating Earth should have on projectiles.[36] When the cannon is fired at eastern target B, cannon and target both travel east at the same speed while the ball is in flight. The ball strikes the target just as it would if the Earth were immobile. When the cannon is fired at northern target E, the target moves more slowly to the east than the cannon and the airborne ball, because the ground moves more slowly at more northern latitudes (the ground hardly moves at all near the pole). Thus the ball follows a curved path over the ground, not a diagonal, and strikes to the east, or right, of the target at G. Source: Wikimedia Commons

Likewise, the French, Jesuit mathematician, Claude François Millet Deschales (1621–1678) drew the same conclusion in his 1674 Cursus seu Mondus Matematicus. The problem is that the Coriolis effect for balls dropped from towers or fired from cannons is extremely small and very difficult to detect.

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The question remained, however, a hotly discussed subject under astronomers and natural philosophers. In 1679, in the correspondence between Newton and Hooke that would eventually lead to Hooke’s priority claim for the law of gravity, Newton proffered a new solution to the problem as to where a ball dropped from a tower would land under the influence of diurnal rotation. In his accompanying diagram Newton made an error, which Hooke surprisingly politely corrected in his reply. This exchange did nothing to improve relations between the two men.

Leonard Euler (1707–1783) worked out the mathematics of the Coriolis effect in 1747 and Pierre-Simon Laplace (1749–1827) introduced the Coriolis effect into his tidal equations in 1778. Finally, Coriolis, himself, published his analysis of the effect that’s named after him in a work on machines with rotating parts, such as waterwheels in 1835, G-G Coriolis (1835), “Sur les équations du mouvement relatif des systèmes de corps”. 

What Riccioli and Deschales didn’t consider was the pendulum. The simple pendulum is a controlled falling object and thus also affected by the Coriolis force. If you release a pendulum and let it swing it doesn’t actually trace out the straight line that you visualise but veers off slightly to the side. Because of the controlled nature of the pendulum this deflection from the straight path is detectable.

For the last three years of Galileo’s life, that is from 1639 to 1642, the then young Vincenzo Viviani (1622–1703) was his companion, carer and student, so it is somewhat ironic that Viviani was the first to observe the diurnal rotation deflection of a pendulum. Viviani carried out experiments with pendulums in part, because his endeavours together with Galileo’s son, Vincenzo (1606-1649), to realise Galileo’s ambition to build a pendulum clock. The project was never realised but in an unpublished manuscript Viviani recorded observing the deflection of the pendulum due to diurnal rotation but didn’t realise what it was and thought it was due to experimental error.

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Vincenzo Viviani (1622- 1703) portrait by Domenico Tempesti Source: Wikimedia Commons

It would be another two hundred years, despite work on the Coriolis effect by Giovanni Borelli (1608–1679), Pierre-Simon Laplace (1749–1827) and Siméon Denis Poisson (1781–1840), who all concentrated on the falling ball thought experiment, before the French physicist Jean Bernard Léon Foucault (1819–1868) finally produced direct empirical evidence of diurnal rotation with his, in the meantime legendary, pendulum.

If a pendulum were to be suspended directly over the Geographical North Pole, then in one sidereal day (sidereal time is measured against the stars and a sidereal day is 3 minutes and 56 seconds shorter than the 24-hour solar day) the pendulum describes a complete clockwise rotation. At the Geographical South Pole the rotation is anti-clockwise. A pendulum suspended directly over the equator and directed along the equator experiences no apparent deflection. Anywhere between these extremes the effect is more complex but clearly visible if the pendulum is large enough and stable enough.

Foucault’s first demonstration took place in the Paris Observatory in February 1851. A few weeks later he made the demonstration that made him famous in the Paris Panthéon with a 28-kilogram brass coated lead bob suspended on a 67-metre-long wire from the Panthéon dome.

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Paris Panthéon Source: Wikimedia Commons

His pendulum had a period of 16.5 seconds and the pendulum completed a full clockwise rotation in 31 hours 50 minutes. Setting up and starting a Foucault pendulum is a delicate business as it is easy to induce imprecision that can distort the observed effects but at long last the problem of a direct demonstration of diurnal rotation had been produced and with it the final demonstration of the truth of the heliocentric hypothesis three hundred years after the publication of Copernicus’ De revolutionibus.

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Léon Foucault, Pendulum Experiment, 1851 Source

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The emergence of modern astronomy – a complex mosaic: Part L

 

By the end of the eighteenth century, Newton’s version of the heliocentric theory was firmly established as the accepted model of the solar system. Whilst not yet totally accurate, a reasonable figure for the distance between the Earth and the Sun, the astronomical unit, had been measured and with it the absolute, rather than relative, sizes of the orbits of the known planets had been calculated. This also applied to Uranus, the then new planet discovered by the amateur astronomer, William Herschel (1738–1822), in 1781; the first planet discovered since antiquity. However, one major problem still existed, which needed to be solved to complete the knowledge of the then known cosmos. Astronomers and cosmologists still didn’t know the distance to the stars. It had long been accepted that the stars were spread out throughout deep space and not on a fixed sphere as believed by the early astronomer in ancient Greece. It was also accepted that because all attempts to measure any stellar parallax down the centuries had failed, the nearest stars must actually be at an unbelievably far distance from the Earth.

Here we meet a relatively common phenomenon in the history of science, almost simultaneous, independent, multiple discoveries of the same fact. After literally two millennia of failures to detect any signs of stellar parallax, three astronomers each succeeded in measuring the parallax of three different stars in the 1830s. This finally was confirmation of the Earth’s annual orbit around, independent of stellar aberration and gave a yardstick for the distance of the stars from the Earth.

The first of our three astronomers was the Scotsman, Thomas Henderson (1798–1844).

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Thomas Henderson Source: Wikimedia Commons

Henderson was born in Dundee where he also went to school. He trained as a lawyer but was a keen amateur astronomer. He came to the attention of Thomas Young (1773-1829), the superintendent of the HM Nautical Almanac Office, after he devised a new method for determining longitude using lunar occultation, that is when a star disappears behind the Moon. Young brought him into the world of astronomy and upon his death recommended Henderson as his successor.

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Copy of a portrait of Thomas Young by Henry Briggs Source: Wikimedia Commons

Henderson didn’t receive to post but was appointed director of the Royal Observatory at the Cape of Good Hope. The observatory had only opened in 1828 after several years delay in its construction. The first director Fearon Fallows (1788–1831), who had overseen the construction of the observatory had died of scarlet fever in 1831 and Henderson was appointed as his successor, arriving in 1832.

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The Royal Observatory Cape of Good Hope in 1857 Illustrated London News, 21 March 1857/Ian Glass Source: Wikimedia Commons

The Cape played a major role in British observational astronomy. In the eighteenth century, it was here that Charles Mason (1728–1786) and Jeremiah Dixon (1733–1779), having been delayed in their journey to their designated observational post in Sumatra, observed the transit of Venus of 1761. John Herschel (1792–1871), the son and nephew of the astronomers William and Caroline Herschel, arrived at the Cape in 1834 and carried extensive astronomical observation there with his own 21-foot reflecting telescope. cooperating with Henderson successor Thomas Maclear. In 1847, Herschel published his Results of Astronomical Observations made at the Cape of Good Hope, which earned him the Copley Medal of the Royal Society.

Manuel John Johnson (1805–1859), director of the observatory on St Helena, drew Henderson’s attention to the fact that Alpha Centauri displayed a high proper motion.

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Ladder Hill Observatory St Helena Source

Proper motion is the perceived motion of a star relative to the other stars. Although the position of the stars relative to each other appears not to change over long periods of time they do. There had been speculation about the possibility of this since antiquity, but it was first Edmund Halley, who in 1718 proved its existence by comparing the measured positions of prominent stars from the historical record with their current positions. A high proper motion is an indication that a star is closer to the Earth.

Aimed with this information Henderson began to try to determine the stellar parallax of Alpha Centauri. However, Henderson hated South Africa and he resigned his position at the observatory in 1833 and returned to Britain. In his luggage he had nineteen very accurate determinations of the position of Alpha Centauri. Back in Britain Henderson was appointed the first Astronomer Royal for Scotland in 1834 and professor for astronomy at the University of Edinburgh, position he held until his death.

Initially Henderson did not try to determine the parallax of Alpha Centauri from his observational data. He thought that he had too few observations and was worried that he would join the ranks of many of his predecessors, who had made false claims to having discovered stellar parallax; Henderson preferred to wait until he had received more observational data from his assistant William Meadows (?–?). This decision meant that Henderson, whose data did in fact demonstrate stellar parallax for Alpha Centauri, who had actually won the race to be the first to determine stellar parallax, by not calculating and publishing, lost the race to the German astronomer Friedrich Wilhelm Bessel (1784–1846).

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Portrait of the German mathematician Friedrich Wilhelm Bessel by the Danish portrait painter Christian Albrecht Jensen Source: Wikimedia Commons

Like Henderson, Bessel was a self-taught mathematician and astronomer. Born in Minden as the son of a minor civil servant, at the age of fourteen he started a seven-year apprenticeship as a clerk to an import-export company in Bremen. Bessel became interested in the navigation on which the company’s ships were dependent and began to teach himself navigation, and the mathematics and astronomy on which it depended. As an exercise he recalculated the orbit of Halley’s Comet, which he showed to the astronomer Heinrich Wilhelm Olbers (1758–1840), who also lived in Bremen.

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Portrait of the german astronomer Heinrich Wilhelm Matthias Olbers (lithography by Rudolf Suhrlandt Source: Wikimedia Commons

Impressed by the young man’s obvious abilities, Olbers became his mentor helping him to get his work on Halley’s Comet published and guiding his astronomical education. In 1806, Olbers obtained a position for Bessel, as assistant to Johann Hieronymus Schröter (1745–1816) in Lilienthal.

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Johann Hieronymus Schröter Source: Wikimedia Commons

Here Bessel served his apprenticeship as an observational astronomer and established an excellent reputation.

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Schröter’s telescope in Lilienthal on which Bessel served his apprenticeship as an observational astronomer

Part of that reputation was built up through his extensive correspondence with other astronomers throughout Europe, including Johann Carl Fried Gauss (1777–1855). It was probably through Gauss’ influence that in 1809 Bessel, at the age of 25, was appointed director of the planned state observatory in Königsberg, by Friedrich Wilhelm III, King of Prussia.

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Königsberg Observatory in 1830. It was destroyed by bombing in the Second World War. Source: Wikimedia Commons

Bessel oversaw the planning, building and equipping of the new observatory, which would be his home and his workplace for the rest of his life. From the beginning he planned to greatly increase the accuracy of astronomical observations and calculation. He started by recalculated the positions of the stars in John Flamsteed’s stellar catalogue, greatly increasing the accuracy of the stellar positions. Bessel also decided to try and solve the problem of determining stellar parallax, although it would be some time before he could undertake that task.

One of the astronomers with whom Bessel took up contact was Friedrich Georg Wilhelm von Struve (1793–1864), who became a good friend and his rival in the search for stellar parallax, although the rivalry was always good natured. Struve was born the son of Jacob Struve (1755–1841), a schoolteacher and mathematician, in Altona then in the Duchy of Holstein, then part of the Denmark–Norway Kingdom and a Danish citizen.

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Friedrich Georg Wilhelm von Struve Source: Wikimedia Commons

Whilst he was still a youth, his father sent him to live in Dorpat (nowadays Tartu) in Estonia with his elder brother, to avoid being drafted into the Napoleonic army. In Dorpat he registered as a student at the university to study, at the wish of his father, philosophy and philology but also registered for a course in astronomy. He financed his studies by working as a private tutor to the children of a wealthy family. He graduated with a degree in philology in 1811 and instead of becoming a history teacher, as his father wished, he took up the formal study of astronomy. The university’s only astronomer, Johann Sigismund Gottfried Huth (1763–1818), was a competent scholar but was an invalid, so Struve basically taught himself and had free run of the university’s observatory whilst still a student, installing the Dolland transit telescope that was still packed in the crates it was delivered in. In 1813 he graduated PhD and was, at the age of just twenty, appointed to the faculty of the university. He immediately began his life’s work, the systematic study of double stars.

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The old observatory building in Dorpat (Tartu) Source: Wikimedia Commons

Like Bessel, Struve was determined to increase the accuracy of observational astronomy. In 1820 whilst in München, to pick up another piece of observational equipment, he visited Europe’s then greatest optical instrument maker, Joseph Fraunhofer (1787–1826), who was putting the finishing touches to his greatest telescopic creation, a refractor with a 9.5-inch lens.

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Joseph Fraunhofer Source: Wikimedia Commons

Struve had found his telescope. He succeeded in persuading the university to purchase the telescope, known as the ‘Great Refractor’ and began his search for observational perfection.

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Frauenhofer’s Great Refractor Source: Wikimedia Commons

Like Struve, Bessel turned to Fraunhofer for the telescope of his dreams. However, unlike Struve, whose telescope was a general-purpose instrument, Bessel desired a special purpose-built heliometer, a telescope with a split objective lens, especially conceived to accurately measure the distance between two observed objects. The first  really practical heliometer was created by John Dolland (1706–1761) to measure the variations in the diameter of the Sun, hence the name. Bessel needed this instrument to fulfil his dream of becoming the first astronomer to accurately measure stellar parallax. Bessel got his Fraunhofer in 1829.

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Königsberger Heliometer Source: Wikimedia Commons

One can get a very strong impression of Bessel’s obsession with accuracy in that he devoted five years to erecting, testing, correcting and controlling his new telescope. In 1834 he was finally ready to take up the task he had set himself. However, other matters that he had to attend to prevented him from starting on his quest.

The Italian astronomer Giuseppe Piazzi (1746–1826), famous for discovering the first asteroid, Ceres, had previously determined that the star 61 Cygni had a very high proper motion, meaning it was probably relatively close to the Earth and this was Bessel’s intended target for his attempt to measure stellar parallax.

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Giuseppe Piazzi pointing at the asteroid Ceres Painting by Giuseppe Velasco (1750–1826). Source: Wikimedia Commons

It was also Struve’s favoured object for his attempt but, unfortunately, he was unable in Dorpat with his telescope to view both 61 Cygni and a reference star against which to measure any observable parallax, so he turned his attention to Vega instead. In 1837, Bessel was more than somewhat surprised when he received a letter from Struve containing seventeen preliminary parallax observations of Vega. Struve admitted that they were not yet adequate to actually determine Vega’s parallax, but it was obvious that he was on his way. Whether Struve’s letter triggered Bessel’s ambition is not known but he relatively soon began a year of very intensive observations of 61 Cygni. In 1838 having checked and rechecked his calculations, and dismantled and thoroughly examined his telescope for any possible malfunctions, he went public with the news that he had finally observed a measurable parallax of 61 Cygni. He sent a copy of his report to John Herschel, President of the Royal Astronomical Society in London. After Herschel had carefully studied the report and after Bessel had answered all of his queries to his satisfaction. Herschel announced to the world that stellar parallax had finally been observed. For his work Bessel was awarded the Gold Medal of the Royal Astronomical Society. Just two months later, Henderson, who had in the meantime done the necessary calculations, published his measurement of the stellar parallax of Alpha Centauri. In 1839 Struve announced his for Vega. Bessel did not rest on his laurels but reassembling his helioscope he spent another year remeasuring 61 Cygni’s parallax correcting his original figures. 

All three measurements were accepted by the astronomical community and both Henderson and Struve were happy to acknowledge Bessel’s priority. There was no sense of rivalry between them and the three men remained good friends. Modern measurements have shown that Bessel’s figures were within 90% of the correct value, Henderson’s with in 75%, but Struve’s were only within 50%. The last is not surprising as Vega is much further from the Earth than either Alpha Centauri or Cygni 61 making it parallax angle much, much smaller and thus considerably more difficult to measure.

In the sixteenth century Tycho Brahe rejected heliocentricity because the failure to detect stellar parallax combined with his fallacious big star argument meant that in a heliocentric system the stars were for him inconceivably far away. I wonder what he would think about the fact that Earth’s nearest stellar neighbour Proxima Centauri is 4.224 lightyears away, that is 3. 995904 x 1013 kilometres!

 

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Filed under History of Astronomy, History of Optics, History of science, History of Technology

A master instrument maker from a small town in the Fränkischen Schweiz

 

Eggolsheim is a small market town about twenty kilometres almost due north of Erlangen in the Fränkischen Schweiz (Franconian Switzerland).

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Eggolsheim Source: Wikimedia Commons

The Fränkischen Schweiz is a hilly area with many rock faces and caves in Middle Franconia, to the north of Nürnberg that is very popular with tourists, day trippers, wanderers, rock-climbers and potholers. It also has lots of old churches and castles.

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Fränkische Schweiz Source Wikimedia Commons

When I first moved to Middle Franconia the Fränkischen Schweiz had the highest density of private breweries of anywhere in the world. It also has many bierkeller that during the summer months attract large crowds of visitors at the weekend. Eggolsheim is these days probably best known for its bierkeller, but in the late fifteenth century it was the birthplace of the Renaissance mathematicus, Georg Hartmann, who would become one of the leading instrument makers in Renaissance Nürnberg in the early sixteenth century.

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Georg Hartmann Source: Astronomie in Nürnberg

Hartmann was born on 9 February 1489. Unfortunately, as with so many Renaissance figures, we know nothing about his background or childhood. He matriculated at the university of Ingolstadt in 1503, which is where people from Franconia often studied as there were no University in either Nürnberg or Bamberg. Johannes Werner and Johannes Stabius, two other members of Nürnberg’s Renaissance mathematical community were graduates of Ingolstadt. In 1506, Hartmann transferred to the University of Köln, where he studied mathematics and theology, graduating in 1510. As was quite common during this period he completed his studies on a journey through Italy between 1510 and 1518. He spent several years in Rome, where he was friends with Andreas Copernicus, the older brother of Nicolas, who died in Rome, possibly of leprosy or syphilis in 1518.

In 1518 Hartmann arrived in Nürnberg, where he was appointed a vicar of the St. Sebaldus Church, one of the two parish churches of the city. Unlike the modern Anglican Church, where the vicar is the principal priest of a church, in the sixteenth century Catholic Church a vicar was a deputy or replacement priest with a special function appointed either permanently or temporarily. He might, for example, be appointed to sing a daily mass in the name of a rich deceased member of the parish, who left a stipend in his will to pay for this service, as another of Nürnberg’s mathematical community, Johannes Schöner, was appointed to do in Kirchehrenbach, also in the Fränkischen Schweiz, in 1523. We don’t know what Hartmann’s specific duties in the St. Sebaldus Church were. In 1522 he was also granted the prebend of the St. Walburga Chapel in Nürnberg.

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St. Sebaldus in Nürnberg Source: Wikimedia Commons

This was a sinecure. It was not unusual for mathematici to receive sinecures from the Church to enable them to carry out their activities as mathematicians, instrument makers or cartographers in the service of the Church. This was certainly the case with Johannes Schöner, who was many years paid as a member of the St Joseph Beneficence in Bamberg but worked as mathematicus, printer and bookbinder for the Bishop. If this was actually so in Hartmann’s case is not known.

When he arrived in Nürnberg he became part of the, for the time, comparatively large community of mathematici, print makers, printer/publishers and instrument makers, which included both Werner and Stabius, the latter as a regular visitor, but both of whom died in 1522. I have written about this group before here and here. It also included Schöner, who only arrived in 1525, Erhard Etzlaub, Johann Neudörffer, Johannes Petreius and Albrecht Dürer.  Central to this group was Willibald Pirckheimer, who although not a mathematicus, was a powerful local figure–humanist scholar, merchant trader, soldier, politician, Dürer’s friend and patron–who had translated Ptolemaeus’ Geographia from Greek into Latin. Hartmann was friends with both Pirckheimer and Dürer, and acted as Schöner’s agent in Nürnberg, selling his globes in the city, during the time Schöner was still living in Kirchehrenbach. Like other members of this group Hartmann also stood in contact with and corresponded with many other scholars throughout Europe; the Nürnberger mathematici were integrated into the European network of mathematici.

Hartmann established himself as one of Nürnberg’s leading scientific instrument makers; he is known to have produced sundials, astrolabes, armillary spheres and globes. None of his armillary spheres or globes are known to have survived, although a few globe gores made by him are extant, an important factor when trying to assess the impact or range of an instrument maker, we can only work with that which endures the ravages of time. We know for example that Hartmann’s friend and colleague, Schöner, produced and sold large numbers of terrestrial and celestial globes but only a small handful of his globes are preserved.

A total of nine of Hartmann’s brass astrolabes are known to have survived and here Hartmann proved to be an innovator.

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Hartmann astrolabe front

 

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Hartmann astrolabe back

As far as is known, Hartmann was the earliest astrolabe maker to introduce serial production of this instrument. It is now assumed that he designed the instruments and then commissioned some of Nürnberg’s numerous metal workers to mass produce the separate parts of the astrolabe, which he them assembled and sold. Nine astrolabes might not seem a lot but compared to other known astrolabe makers, from whom often just one or two instruments are known, this is a comparatively large number. This survival rate suggests that Hartmann made and sold a large number of his mass-produced instruments.  

With his sundials the survival rate is much higher, there are seventy-five know Hartmann sundials in collection around the world. Hartmann made sundials of every type in brass, gold and ivory but is perhaps best known for his portable diptych sundials, a Nürnberg specialty. A diptych consists of two flat surfaces, usually made of ivory, connected by a hinge that fold flat to be put into a pocket. When opened the two surfaces are at the correct angle and joined by a thread, which functions as the dial’s gnomon. The lower surface contains a compass to help the user correctly orientate his dial during use.

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Hartmann diptych sundial open

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Hartmann diptych sundial closed

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Open diptych sundial showing string gnomon and Hartmann’s name

Hartmann also made elaborate dials such as this ivory crucifix dial.

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One thing that Hartmann is noted for is his paper instruments*. These are the elements for instrument printed on sheets of paper. These can be cut out and glued to thin wood backing to construct cheap but fully functioning instruments. Of course, the survival rates of such instruments are very low and in fact only one single paper astrolabe printed by Hartmann is known to have survived.

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Hartmann paper astrolabe Source:History of Science Museum Oxford

However, we are lucky that several hundred sheets of Hartmann’s printed paper instruments have survived and are now deposited in various archives. There have been discussions, as to whether these were actually intended to be cut out and mounted onto wood to create real instruments or whether there are intended as sales archetypes, designed to demonstrate to customers the instruments that Hartmann would then construct out of ivory, brass or whatever.

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Printed paper instrument part

 

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Apart from designing and constructing instruments Hartman was obviously engaged in writing a book on how to design and construct instrument. Several partial manuscripts of this intended work exist but the book was never finished in his lifetime. The book however does reveal his debt as an instrument designer to Johannes Stöffler’s Elucidatio fabricae usuque astrolabii.

As a manufacturer of portable sun dials with built in compasses Hartmann also developed a strong interest in the magnetic compass. Whilst living in Rome he determined the magnetic declination of the city, i.e., how much a compass needle varies from true north in that location. Hartmann also appears to have been the first to discover magnetic dip or inclination, which information he shared with Duke Albrecht of Prussia in a letter in 1544, but he never published his discovery, so it is usually credited to the English mariner Robert Norman, who published the discovery in his The Newe Attractive, shewing The Nature, Propertie, and manifold Vertues of the Loadstone; with the declination of the Needle, Touched therewith, under the Plaine of the Horizon in 1581.

The only book that Hartmann did publish in his lifetime was an edition of John Peckham’s Perspectiva communis, the most widely used medieval optic textbook, which was printed by Johannes Petreius in 1542.

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Hartmann died in Nürnberg in 1564 and was buried in the St Johannes graveyard, outside the city walls, where the graves of his friend Pirckheimer, Dürer and Petreius can also be found amongst many other prominent citizens of the Renaissance city.  

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Hartmann’s grave Source: Astronomie in Nürnberg

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Hartmann’s epitaph Source: Astronomie in Nürnberg

  • For a detailed description of Hartmann’s printed paper instruments see: Suzanne Karr Schmidt, Interactive and Sculptural Printmaking in the Renaissance, Brill, 2017

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Filed under History of Astronomy, History of science, History of Technology, Renaissance Science

Microscopes & Submarines

The development of #histSTM in the early decades of the Dutch Republic, or Republic of the Seven United Netherlands, to give it its correct name, was quite extraordinary. Alongside the development of cartography and globe making, the most advanced in the whole of Europe, there were important figures such as the engineer, mathematician and physicist, Simon Stevin, the inventors of the telescope Hans Lipperhey and Jacob Metius, the mathematical father and son Rudolph and Willebrord Snel van Royan and Isaac Beeckman one of the founders of the mechanical philosophy in physics amongst others. However, one of the most strange and wonderful figures in the Netherlands during this period was, without doubt, the engineer, inventor, (al)chemist, optician and showman Cornelis Jacobszoon Drebbel (1571–1631).

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Source: Wikimedia Commons

Drebbel is one of those larger than life historical figures, where it becomes difficult to separate the legends and the myths from the known facts, but I will try to keep to the latter. He was born to Jacob Drebbel an Anabaptist in Alkmaar in the province of North Holland. He seems not to have received much formal education but in about 1587 he started attending the Academy of the printmaker, draftsman and painter Hendrick Goltzius (1558–1617) in Haarlem also in North Holland.

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Hendrick Goltzius – Self-Portrait, c. 1593-1594 – Google Art Project Source: Wikimedia Commons

Goltzius was regarded as the leading engraver in the Netherlands during the period and he was also an active alchemist. Drebbel became a skilled engraver under Goltzius’ instruction and also acquired an interest in alchemy. In 1595 he married Sophia Jansdochter Goltzius, Hendrick’s younger sister. They had at least six children of which four survived into adulthood. The legend says that Sophia’s prodigal life style drove Drebbel’s continual need to find better sources for earning money.

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Drebbel’s town plan of Alkmaar 1597 Source: Wikimedia Commons

Drebbel initially worked as an engraver, cartographer and painter but somewhere down the line he began to work as an inventor and engineer.

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Astronomy [from the series The Seven Liberal Arts]. Engraving by Drebbel Source: Wikimedia Commons

Not surprisingly, for a Netherlander, he a turned to hydraulic engineering receiving a patent for a water supply system in 1598. In 1600 he built a fountain at the Noorderpoort in Middelburg and at the end of his life living in England he was involved in a plan to drain the Fens. At some point, possibly when he was living in Middelburg, he learnt the craft of lens grinding, which would play a central roll in his life.

Also in 1598 he acquired a patent for Perpetuum mobile but which he, however, had not invented. The so-called Perpetuum mobile was a sort of clock, which was in reality powered in changes by the air temperature and air pressure had actually been invented by Jakob Dircksz de Graeff (1571–1638), an influential politician and natural philosopher, who was a friend of both Constantijn Huygens and René Descartes, and Dr Pieter Jansz Hooft (1574/5–1636) a politician, physician and schoolteacher.

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Jakob Dircksz de Graeff Source: Wikimedia Commons

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Pieter Jansz Hooft (1619), Attributed to Michiel van Mierevelt Source: Wikimedia Commons

Drebbel not only patented the Perpetuum mobile but also claimed to have invented it. His increasing reputation driven by this wonder machine earned his an invitation to the court of King James VI &I in London as the guest of the crown prince Henry in 1604. When on the court in London the Queen accidentally broke the Perpetuum mobile, Drebbel was unable to repair it.

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The barometric clock of Cornelis Drebbel patented in 1598 and then known as “perpetuum mobile”. Print by Hiesserle von Choda (1557-1665) Source: Wikimedia Commons

At the court in London he was responsible for staging masques, a type of play with poetry, music, dance, and songs that was popular in the sixteenth and seventeenth centuries. He designed and built the stage sets and wonderful machines to enchant the audiences. Drebbel was by no means the only scientist-engineer to be employed to stage such entertainments during the Early Modern Period but he appears to have been very good at it. It was almost certainly Drebbel, who through his contacts imported from the Netherlands the first ever telescope to be seen in England, which was presented to James at the high point of a masque in 1609. He also built a magic lantern and a camera obscura with which he also entertained the members of the court.

Drebbel’s reputation grew to the point where he received an invitation to the court of the Holly Roman Empire, Rudolf II, in Prague in October 1610. Rudolf liked to surround himself with what might be termed wonder workers. Amongst those who had served in this capacity in Prague were Tycho Brahe, John Dee, Edward Kelley, Johannes Kepler and Jost Bürgi. There are no reports of any interactions between Drebbel and either Kepler or Bürgi, who were all on the court of Rudolf at the same time. In Prague he once again functioned as a court entertainer or showman.

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AACHEN, Hans von – Portrait of Emperor Rudolf II Source: Wikimedia Commons

Rudolf was deposed by his brother Archduke Mathias in 1611and Drebbel was imprisoned for about a year. Following the death of Rudolf in 1612, Drebbel was released from prison and returned to London. Here, however, his situation was not as good as previously because Henry, his patron, had died in 1612. He kept his head above water as a lens grinder and instrument maker.

As a chemist Drebbel published his best-known written work Een kort Tractaet van de Natuere der Elemente (A short treatise of the nature of the elements) (Haarlem, 1621).

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He was supposedly involved in the invention of the explosive mercury fulminate, Hg(CNO)2, but this is disputed. He also developed other explosive mixtures. He invented a chicken incubator with a mercury thermostat to keep it at a constant, stable temperature. This is one of the earliest feedback controlled devices ever created. He also developed and demonstrated a functioning air conditioning system.

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Error-controlled regulator using negative feedback, depicting Cornelius Drebbel’s thermostat-controlled incubator of circa 1600. Source: Wikimedia Commons

He didn’t himself exploit one of his most successful discoveries, one that he made purely by accident. He dropped a flask of aqua regia (a mixture of nitric and hydrochloric acid, normally used to dissolve gold) onto a tin windowsill and discovered that stannous chloride (SnCl2) makes the colour of carmine (the red dye obtained from the cochineal insect) much brighter and more durable. Although Drebbel didn’t exploit this discovery his daughters Anna and Catherina and their husbands the brothers, Abraham and Johannes Sibertus Kuffler (a German inventor and chemist) did, setting up dye works originally in Leiden and then later in Bow in London. The colour was known as Colour Kuffler of Bow Dye and was very successful. Kuffler later continued his father-in-law’s development of self-regulating ovens that he demonstrated to the Royal Society.

In the early 1620s Constantijn Huygens, the father of Christiaan, came to London on a diplomatic mission. He made the acquaintance of Drebbel, who demonstrated his magic lantern and his camera obscura for the Dutch diplomat. Huygens was much impressed by his landsman and for a time became his pupil learning how to grind lenses, a skill that he might have passed onto his sons.

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Constantijn Huygens (1596-1687), by Michiel Jansz van Mierevelt. Source: Wikimedia Commons

It is not known, who actually invented the microscope and it’s more than likely that the principle of the microscope was discovered by several people, all around the same time, who like Galileo looked through their Galilean or Dutch telescope the wrong way round. What, however, seems to be certain is that Drebbel is the first person known to have constructed a Keplerian telescope, that is with two convex lenses rather than a concave and a convex lens. As with all of his other optical instruments, Drebbel put on microscope demonstration introducing people to the microscopic world, as always the inventor as showman.

Drebbel’s most famous invention was without doubt his submarine. This is claimed to be the first-ever navigable submarine but has become the stuff of legends, how much of story is fact is difficult to assess. His submarine consisted of a wooden frame covered in leather, and one assumes waterproofed in someway; it was powered by oar.

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Artistic representation of Drebbel’s submarine, artist unknown Source: Wikimedia Commons

It had bladders inside that were filled with water to enable the submarine to submerge; the bladders were emptied when the vessel was required to surface. In total between 1620 and 1624 Drebbel built three different vessels increasing in size. The final submarine had six oars and could carry up to sixteen passengers. Drebbel gave public demonstrations with this vessel on the river Thames. According to reports the vessel dived to a depth of four to five metres and remained submerged for three hours traveling from Westminster and Greenwich and back again. Assuming the reports to be true, there has been much speculation as to how fresh air was supplied inside the closed vessel. These speculations include a mechanical solution with some form of snorkel as well as chemical solutions with some sort of chemical apparatus to generate oxygen. It is also reported that Drebbel took King James on a dive under the Thames. Despite all of this Drebbel failed to find anybody, who would be prepared to finance a serious use of his submarine.

In the later 1620s Drebbel served the Duke of Buckingham as a military advisor but his various suggestions for weapons proved impractical and failed, the British blaming  the inventor and Drebbel blaming the English soldiers, finally ruining whatever reputation he still had. As already stated above towards the end of his life he was supposedly involved in a scheme to drain the Fens but the exact nature of his involvement remains obscure. Drebbel died in financial straights in 1633 in London, where he was scraping a living running a tavern on the banks of the Thames.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Filed under History of Alchemy, History of Cartography, History of Chemistry, History of Optics, History of Technology, Renaissance Science

Our medieval technological inheritance.

“Positively medieval” has become a universal put down for everything considered backward, ignorant, dirty, primitive, bigoted, intolerant or just simply stupid in our times. This is based on a false historical perspective that paints the Middle Ages as all of these things and worse. This image of the Middle Ages has its roots in the Renaissance, when Renaissance scholars saw themselves as the heirs of all that was good, noble and splendid in antiquity and the period between the fall of the Roman Empire and their own times as a sort of unspeakable black pit of ignorance and iniquity. Unfortunately, this completely false picture of the Middle Ages has been extensively propagated in popular literature, film and television.

Particularly in the film and television branch, a film or series set in the Middle Ages immediately calls for unwashed peasants herding their even filthier swine through the mire in a village consisting of thatch roofed wooden hovels, in order to create the ‘correct medieval atmosphere’. Add a couple of overweight, ignorant, debauching clerics and a pox marked whore and you have your genuine medieval ambient. You can’t expect to see anything vaguely related to science or technology in such presentations.

Academic medieval historians and historians of science and technology have been fighting an uphill battle against these popular images for many decades now but their efforts rarely reach the general lay public against the flow of the latest bestselling medieval bodice rippers or TV medieval murder mystery. What is needed, is as many semi-popular books on the various aspects of medieval history as possible. Whereby with semi-popular I mean, written for the general lay reader but with its historical facts correct. One such new volume is John Farrell’s The Clock and the Camshaft: And Other Medieval Inventions We Still Can’t Live Without.[1]

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Farrell’s book is a stimulating excursion through the history of technological developments and innovation in the High Middle Ages that played a significant role in shaping the modern world.  Some of those technologies are genuine medieval discoveries and developments, whilst others are ones that either survived or where reintroduced from antiquity. Some even coming from outside of Europe. In each case Farrell describes in careful detail the origins of the technology in question and if known the process of transition into European medieval culture.

The book opens with agricultural innovations, the deep plough, the horse collar and horse shoes, which made it possible to use horses as draught animals instead of or along side oxen, and new crop rotation systems. Farrell explains why they became necessary and how they increased food production leading indirectly to population growth.

Next up we have that most important of commodities power and the transition from the hand milling of grain to the introduction of first watermills and then windmills into medieval culture. Here Farrell points out that our current knowledge would suggest that the more complex vertical water mill preceded the simpler horizontal water mill putting a lie to the common precept that simple technology always precedes more complex technology. At various points Farrell also addresses the question as to whether technological change drives social and culture change or the latter the former.

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Having introduced the power generators, we now have the technological innovations necessary to adapt the raw power to various industrial tasks, the crank and the camshaft. This is fascinating history and the range of uses to which mills were then adapted using these two ingenious but comparatively simple power take offs was very extensive and enriching for medieval society. One of those, in this case an innovation from outside of Europe, was the paper mill for the production of that no longer to imagine our society without, paper. This would of course in turn lead to that truly society-changing technology, the printed book at the end of the Middle Ages.

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Along side paper perhaps the greatest medieval innovation was the mechanical clock. At first just a thing of wonder in the towers of some of Europe’s most striking clerical buildings the mechanical clock with its ability to regulate the hours of the day in a way that no other time keeper had up till then gradually came to change the basic rhythms of human society.

Talking of spectacular clerical buildings the Middle Ages are of course the age of the great European cathedrals. Roman architecture was block buildings with thick, massive stonewalls, very few windows and domed roofs. The art of building in stone was one of the things that virtually disappeared in the Early Middle Ages in Europe. It came back initially in an extended phase of castle building. Inspired by the return of the stonemason, medieval, European, Christian society began the era of building their massive monuments to their God, the medieval cathedrals. Introducing architectural innovation like the pointed arch, the flying buttress and the rib vaulted roof they build large, open buildings flooded with light that soared up to the heavens in honour of their God. Buildings that are still a source of wonder today.

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In this context it is important to note that Farrell clearly explicates the role played by the Catholic Church in the medieval technological innovations, both the good and the bad. Viewed with hindsight the cathedrals can be definitely booked for the good but the bad? During the period when the watermills were introduced into Europe and they replaced the small hand mills that the people had previously used to produce their flour, local Church authorities gained control of the mills, a community could only afford one mill, and forced the people to bring their grain to the Church’s mill at a price of course. Then even went to the extent of banning the use of hand mills.

People often talk of the Renaissance and mean a period of time from the middle of the fifteenth century to about the beginning of the seventeenth century. However, for historians of science there was a much earlier Renaissance when scholars travelled to the boundaries between Christian Europe and the Islamic Empire in the twelfth and thirteenth centuries in order to reclaim the knowledge that the Muslims had translated, embellished and extended in the eight and ninth centuries from Greek sources. This knowledge enriched medieval science and technology in many areas, a fact that justifies its acquisition here in a book on technology.

Another great medieval invention that still plays a major role in our society, alongside the introduction of paper and the mechanical clock are spectacles and any account of medieval technological invention must include their emergence in the late thirteenth century. Spectacles are something that initially emerged from Christian culture, from the scriptoria of the monasteries but spread fairly rapidly throughout medieval society. The invention of eyeglasses would eventually lead to the invention of the telescope and microscope in the early seventeenth century.

Another abstract change, like the translation movement during that first scientific Renaissance, was the creation of the legal concept of the corporation. This innovation led to the emergence of the medieval universities, corporations of students and/or their teachers. There is a direct line connecting the universities that the Church set up in some of the European town in the High Middle Ages to the modern universities throughout the world. This was a medieval innovation that truly helped to shape our modern world.

Farrell’s final chapter in titled The Inventions of Discovery and deals both with the medieval innovations in shipbuilding and the technology of the scientific instruments, such as astrolabe and magnetic compass that made it possible for Europeans to venture out onto the world’s oceans as the Middle Ages came to a close. For many people Columbus’ voyage to the Americas in 1492 represents the beginning of the modern era but as Farrell reminds us all of the technology that made his voyage possible was medieval.

All of the above is a mere sketch of the topics covered by Farrell in his excellent book, which manages to pack an incredible amount of fascinating information into what is a fairly slim volume. Farrell has a light touch and leads his reader on a voyage of discovery through the captivating world of medieval technology. The book is beautifully illustrated by especially commissioned black and white line drawing by Ryan Birmingham. There are endnotes simply listing the sources of the material in main text and an extensive bibliography of those sources. The book also has, what I hope, is a comprehensive index.[2]

Farrell’s book is a good, readable guide to the world of medieval technology aimed at the lay reader but could also be read with profit by scholars of the histories of science and technology and as an ebook or a paperback is easily affordable for those with a small book buying budget.

So remember, next time you settle down with the latest medieval pot boiler with its cast of filthy peasants, debauched clerics and pox marked whores that the paper that it’s printed on and the reading glasses you are wearing both emerged in Europe in the Middle Ages.

[1] John W. Farrell, The Clock and the Camshaft: And Other Medieval Inventions We Still Can’t Live Without, Prometheus Books, 2020.

[2] Disclosure: I was heavily involved in the production of this book, as a research assistant, although I had nothing to do with either the conception or the actual writing of the book that is all entirely John Farrell’s own work. However, I did compile the index and I truly hope it will prove useful to the readers.

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Filed under Book Reviews, History of science, History of Technology, Mediaeval Science

The Electric Showman

The are some figures in #histSTM, who, through some sort of metamorphosis, acquire the status of cult gurus, who were somehow super human and if only they had been properly acknowledged in their own times would have advanced the entire human race by year, decades or even centuries. The most obvious example is Leonardo da Vinci, who apparently invented, discovered, created everything that was worth inventing, discovering, creating, as well as being the greatest artist of all time. Going back a few centuries we have Roger Bacon, who invented everything that Leonardo did but wasn’t in the same class as a painter. Readers of this blog will know that one of my particular bugbears is Ada Lovelace, whose acolytes claim singlehandedly created the computer age. Another nineteenth century figure, who has been granted god like status is the Serbian physicist and inventor, Nikola Tesla (1856–1943).

The apostles of Tesla like to present him in contrast to, indeed in battle with, Thomas Alva Edison (1847–1931). According to their liturgy Tesla was a brilliant, original genius, who invented everything electrical and in so doing created the future, whereas Edison was poseur, who had no original ideas, stole everything he is credited with having invented and exploited the genius of other to create his reputation and his fortune. You don’t have to be very perceptive to realise that these are weak caricatures that almost certainly bear little relation to the truth. That this is indeed the case is shown by a new, levelheaded biography of Tesla by Iwan Rhys Morus, Tesla and the Electric Future.[1]

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If anyone is up to the job of presenting a historically accurate, balanced biography of Tesla, then it is Morus, who is professor of history at Aberystwyth University and who has established himself as an expert for the history of electricity in the nineteenth century with a series of excellent monographs on the topic, and yes he delivers.

Anybody who picks up Morus’ compact biography looking for a blow by blow description of the epic war between Tesla and Edison is going to be very disappointed, because as Morus points out it basically never really took place; it is a myth. What we get instead is a superb piece of contextual history. Morus presents a widespread but deep survey of the status of electricity in the second half of the nineteenth century and the beginnings of the twentieth century into which he embeds the life story of Tesla.

We have the technological and scientific histories of electricity but also the socio-political history of the role that electricity during the century and above all the futurology. Electricity was seen as the key to the future in all areas of life in the approaching twentieth century. Electricity was hyped as the energy source of the future, as the key to local and long distant communication, and as a medical solution to both physical and psychological illness. In fact it appears that electricity was being touted as some sort of universal panacea for all of societies problems and ills. It was truly the hype of the century. Electricity featured big in the widely popular world exhibitions beginning with the Great Exhibition at Crystal Palace in 1851.

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In these world fairs electricity literally outshone all of the other marvels and wonders on display.

The men, who led the promotion of this new technology, became stars, prophets of an electrical future, most notably Thomas Alva Edison, who became known as the Wizard of Menlo Park.

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Far from the popular image of Edison being Tesla’s sworn enemy, he was the man, who brought Tesla to America and in doing so effectively launched Tesla’s career. Edison also served as a role model for Tesla; from Edison, Tesla learnt how to promote and sell himself as a master of the electric future.

Morus takes us skilfully through the battle of the systems, AC vs. DC in which Tesla, as opposed to popular myth, played very little active part having left Westinghouse well before the active phase. His technology, patented and licenced to Westinghouse, did, however, play a leading role in Westinghouse’s eventually victory in this skirmish over Edison, establishing Tesla as one of the giants in the electricity chess game. Tesla proceeded to establish his reputation as a man of the future through a series of public lectures and interviews, with the media boosting his efforts.

From here on in Tesla expounded ever more extraordinary, visionary schemes for the electric future but systematically failed to deliver.

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His decline was long drawn out and gradual rather than spectacular and the myths began to replace the reality. The electric future forecast throughout the second half of the nineteenth century was slowly realised in the first half of the twentieth but Tesla played almost no role in its realisation.

Morus is himself a master of nineteenth century electricity and its history, as well as a first class storyteller, and in this volume he presents a clear and concise history of the socio-political, public and commercial story of electricity as it came to dominate the world, woven around a sympathetic but realistic biography of Nikola Tesla. His book is excellently researched and beautifully written, making it a real pleasure to read.  It has an extensive bibliography of both primary and secondary sources. The endnotes are almost exclusively references to the bibliography and the whole is rounded off with an excellent index. The book is well illustrated with a good selection of, in the meantime ubiquitous for #histSTM books, grey in grey prints.

Morus’ book has a prominent subtext concerning how we view our scientific and technological future and it fact this is probably the main message, as he makes clear in his final paragraph:

It is a measure of just what a good storyteller about future worlds Tesla was that we still find the story so compelling. It is also the way we still tend to tell stories about imagined futures now. We still tend to frame the way we think about scientific and technological innovation – the things on which our futures will depend – in terms of the interventions of heroic individuals battling against the odds. A hundred years after Tesla, it might be time to start thinking about other ways of talking about the shape of things to come and who is responsible who is responsible for shaping them.

If you want to learn about the history of electricity in the nineteenth century, the life of Nikola Tesla or how society projects its technological futures then I really can’t recommend Iwan Rhys Morus excellent little volume enough. Whether hardback or paperback it’s really good value for money and affordable for even the smallest of book budgets.

[1] Iwan Rhys Morus, Tesla and the Electric Future, Icon books, London, 2019

 

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Filed under Book Reviews, History of Physics, History of science, History of Technology