Category Archives: History of Technology

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).


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.


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.


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.


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.


Jakob Dircksz de Graeff Source: Wikimedia Commons


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.


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.


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).


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.


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.


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.


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.

















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]


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.


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.


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.


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.


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]


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.


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.


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.


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



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

How Renaissance Nürnberg became the Scientific Instrument Capital of Europe

This is a writen version of the lecture that I was due to hold at the Science and the City conference in London on 7 April 2020. The conference has for obvious reasons been cancelled and will now take place on the Internet. You can view the revised conference program here.

The title of my piece is, of course, somewhat hyperbolic, as far as I know nobody has ever done a statistical analysis of the manufacture of and trade in scientific instruments in the sixteenth century. However, it is certain that in the period 1450-1550 Nürnberg was one of the leading European centres both for the manufacture of and the trade in scientific instruments. Instruments made in Nürnberg in this period can be found in every major collection of historical instruments, ranging from luxury items, usually made for rich patrons, like the column sundial by Christian Heyden (1526–1576) from Hessen-Kassel


Column Sundial by Christian Heyden Source: Museumslandschaft Hessen-Kassel

to cheap everyday instruments like this rare (rare because they seldom survive) paper astrolabe by Georg Hartman (1489–1564) from the MHS in Oxford.


Paper and Wood Astrolabe Hartmann Source: MHS Oxford

I shall be looking at the reasons why and how Nürnberg became such a major centre for scientific instruments around 1500, which surprisingly have very little to do with science and a lot to do with geography, politics and economics.

Like many medieval settlements Nürnberg began simply as a fortification of a prominent rock outcrop overlooking an important crossroads. The first historical mention of that fortification is 1050 CE and there is circumstantial evidence that it was not more than twenty or thirty years old. It seems to have been built in order to set something against the growing power of the Prince Bishopric of Bamberg to the north. As is normal a settlement developed on the downhill slopes from the fortification of people supplying services to it.


A fairly accurate depiction of Nürnberg from the Nuremberg Chronicle from 1493. The castles (by then 3) at the top with the city spreading down the hill. Large parts of the inner city still look like this today

Initially the inhabitants were under the authority of the owner of the fortification a Burggraf or castellan. With time as the settlement grew the inhabitants began to struggle for independence to govern themselves.

In 1200 the inhabitants received a town charter and in 1219 Friedrich II granted the town of Nürnberg a charter as a Free Imperial City. This meant that Nürnberg was an independent city-state, which only owed allegiance to the king or emperor. The charter also stated that because Nürnberg did not possess a navigable river or any natural resources it was granted special tax privileges and customs unions with a number of southern German town and cities. Nürnberg became a trading city. This is where the geography comes into play, remember that important crossroads. If we look at the map below, Nürnberg is the comparatively small red patch in the middle of the Holy Roman Empire at the beginning of the sixteenth century. If your draw a line from Paris to Prague, both big important medieval cities, and a second line from the border with Denmark in Northern Germany down to Venice, Nürnberg sits where the lines cross almost literally in the centre of Europe. Nürnberg also sits in the middle of what was known in the Middle Ages as the Golden Road, the road that connected Prague and Frankfurt, two important imperial cities.


You can also very clearly see Nürnberg’s central position in Europe on Erhard Etzlaub’s  (c. 1460–c. 1531) pilgrimage map of Europe created for the Holy Year of 1500. Nürnberg, Etzlaub’s hometown, is the yellow patch in the middle. Careful, south is at the top.


Over the following decades and centuries the merchant traders of Nürnberg systematically expanded their activities forming more and more customs unions, with the support of various German Emperors, with towns, cities and regions throughout the whole of Europe north of Italy. Nürnberg which traded extensively with the North Italian cities, bringing spices, silk and other eastern wares, up from the Italian trading cities to distribute throughout Europe, had an agreement not to trade with the Mediterranean states in exchange for the Italians not trading north of their northern border.

As Nürnberg grew and became more prosperous, so its political status and position within the German Empire changed and developed. In the beginning, in 1219, the Emperor appointed a civil servant (Schultheis), who was the legal authority in the city and its judge, especially in capital cases. The earliest mention of a town council is 1256 but it can be assumed it started forming earlier. In 1356 the Emperor, Karl IV, issued the Golden Bull at the Imperial Diet in Nürnberg. This was effectively a constitution for the Holy Roman Empire that regulated how the Emperor was to be elected and, who was to be appointed as the Seven Prince-electors, three archbishops and four secular rulers. It also stipulated that the first Imperial Diet of a newly elected Emperor was to be held in Nürnberg. This stipulation reflects Nürnberg’s status in the middle of the fourteenth century.

The event is celebrated by the mechanical clock ordered by the town council to be constructed for the Frauenkirche, on the market place in 1506 on the 150th anniversary of the Golden Bull, which at twelve noon displays the seven Prince-electors circling the Emperor.


Mechanical clock on the Frauenkirche overlooking the market place in Nürnberg. Ordered by the city council in 1506 to celebrate the 150th anniversary of the issuing of the Golden Bull at the Imperial Diet in 1356

Over time the city council had taken more and more power from the Schultheis and in 1385 they formally bought the office, integrating it into the councils authority, for 8,000 gulden, a small fortune. In 1424 Emperor, Sigismund appointed Nürnberg the permanent residence of the Reichskleinodien (the Imperial Regalia–crown, orb, sceptre, etc.).


The Imperial Regalia

This raised Nürnberg in the Imperial hierarchy on a level with Frankfurt, where the Emperor was elected, and Aachen, where he was crowned. In 1427, the Hohenzollern family, current holders of the Burggraf title, sold the castle, which was actually a ruin at that time having been burnt to the ground by the Bavarian army, to the town council for 120,000 gulden, a very large fortune. From this point onwards Nürnberg, in the style of Venice, called itself a republic up to 1806 when it was integrated into Bavaria.

In 1500 Nürnberg was the second biggest city in Germany, after Köln, with a population of approximately 40,000, about half of which lived inside the impressive city walls and the other half in the territory surrounding the city, which belonged to it.


Map of the city-state of Nürnberg by Abraham Ortelius 1590. the city itself is to the left just under the middle of the map. Large parts of the forest still exists and I live on the northern edge of it, Dormitz is a neighbouring village to the one where I live.

Small in comparison to the major Italian cities of the period but even today Germany is much more decentralised with its population more evenly distributed than other European countries. It was also one of the richest cities in the whole of Europe.


Nürnberg, Plan by Paul Pfinzing, 1594 Castles in the top left hand corner

Nürnberg’s wealth was based on two factors, trading, in 1500 at least 27 major trade routes ran through Nürnberg, which had over 90 customs unions with cities and regions throughout Europe, and secondly the manufacture of trading goods. It is now time to turn to this second branch of Nürnberg’s wealth but before doing so it is important to note that whereas in other trading centres in Europe individual traders competed with each other, Nürnberg function like a single giant corporation, with the city council as the board of directors, the merchant traders cooperating with each other on all levels for the general good of the city.

In 1363 Nürnberg had more than 1200 trades and crafts masters working in the city. About 14% worked in the food industry, bakers, butchers, etc. About 16% in the textile industry and another 27% working leather. Those working in wood or the building branch make up another 14% but the largest segment with 353 masters consisted of those working in metal, including 16 gold and silver smiths. By 1500 it is estimated that Nürnberg had between 2,000 and 3,000 trades and crafts master that is between 10 and 15 per cent of those living in the city with the metal workers still the biggest segment. The metal workers of Nürnberg produced literally anything that could be made of metal from sewing needles and nails to suits of armour. Nürnberg’s reputation as a producer rested on the quality of its metal wares, which they sold all over Europe and beyond. According to the Venetian accounts books, Nürnberg metal wares were the leading export goods to the orient. To give an idea of the scale of production at the beginning of the 16th century the knife makers and the sword blade makers (two separate crafts) had a potential production capacity of 80,000 blades a week. The Nürnberger armourers filled an order for armour for 5,000 soldiers for the Holy Roman Emperor, Karl V (1500–1558).

The Nürnberger craftsmen did not only produce goods made of metal but the merchant traders, full blood capitalists, bought into and bought up the metal ore mining industry–iron, copper, zinc, gold and silver–of Middle Europe, and beyond, (in the 16th century they even owned copper mines in Cuba) both to trade in ore and to smelt ore and trade in metal as well as to ensure adequate supplies for the home production. The council invested heavily in the industry, for example, providing funds for the research and development of the world’s first mechanical wire-pulling mill, which entered production in 1368.


The wirepulling mills of Nürnberg by Albrecht Dürer

Wire was required in large quantities to make chainmail amongst other things. Around 1500 Nürnberg had monopolies in the production of copper ore, and in the trade with steel and iron.  Scientific instruments are also largely made of metal so the Nürnberger gold, silver and copper smiths, and toolmakers also began to manufacture them for the export trade. There was large scale production of compasses, sundials (in particular portable sundials), astronomical quadrants, horary quadrants, torquetum, and astrolabes as well as metal drawing and measuring instruments such as dividers, compasses etc.

The city corporation of Nürnberg had a couple of peculiarities in terms of its governance and the city council that exercised that governance. Firstly the city council was made up exclusively of members of the so-called Patrizier. These were 43 families, who were regarded as founding families of the city all of them were merchant traders. There was a larger body that elected the council but they only gave the nod to a list of the members of the council that was presented to them. Secondly Nürnberg had no trades and crafts guilds, the trades and crafts were controlled by the city council. There was a tight control on what could be produced and an equally tight quality control on everything produced to ensure the high quality of goods that were traded. What would have motivated the council to enter the scientific instrument market, was there a demand here to be filled?

It is difficult to establish why the Nürnberg city corporation entered the scientific instrument market before 1400 but by the middle of the 15th century they were established in that market. In 1444 the Catholic philosopher, theologian and astronomer Nicolaus Cusanus (1401–1464) bought a copper celestial globe, a torquetum and an astrolabe at the Imperial Diet in Nürnberg. These instruments are still preserved in the Cusanus museum in his birthplace, Kues on the Mosel.


The Cusanus Museum in Kue

In fact the demand for scientific instrument rose sharply in the 15th & 16th centuries for the following reasons. In 1406 Jacopo d’Angelo produced the first Latin translation of Ptolemy’s Geographia in Florence, reintroducing mathematical cartography into Renaissance Europe. One can trace the spread of the ‘new’ cartography from Florence up through Austria and into Southern Germany during the 15th century. In the early 16th century Nürnberg was a major centre for cartography and the production of both terrestrial and celestial globes. One historian of cartography refers to a Viennese-Nürnberger school of mathematical cartography in this period. The availability of the Geographia was also one trigger of a 15th century renaissance in astronomy one sign of which was the so-called 1st Viennese School of Mathematics, Georg von Peuerbach (1423–1461) and Regiomontanus (1436–176), in the middle of the century. Regiomontanus moved to Nürnberg in 1471, following a decade wandering around Europe, to carry out his reform of astronomy, according to his own account, because Nürnberg made the best astronomical instruments and had the best communications network. The latter a product of the city’s trading activities. When in Nürnberg, Regiomontanus set up the world’s first scientific publishing house, the production of which was curtailed by his early death.

Another source for the rise in demand for instruments was the rise in interest in astrology. Dedicated chairs for mathematics, which were actually chairs for astrology, were established in the humanist universities of Northern Italy and Krakow in Poland early in the 15th century and then around 1470 in Ingolstadt. There were close connections between Nürnberg and the Universities of Ingolstadt and Vienna. A number of important early 16th century astrologers lived and worked in Nürnberg.

The second half of the 15th century saw the start of the so-called age of exploration with ships venturing out of the Iberian peninsular into the Atlantic and down the coast of Africa, a process that peaked with Columbus’ first voyage to America in 1492 and Vasco da Gama’s first voyage to India (1497–199). Martin Behaim(1459–1507), son of a Nürnberger cloth trading family and creator of the oldest surviving terrestrial globe, sat on the Portuguese board of navigation, probably, according to David Waters, to attract traders from Nürnberg to invest in the Portuguese voyages of exploration.  This massively increased the demand for navigational instruments.


The Erdapfel–the Behaim terrestial globe Germanische National Museum

Changes in the conduct of wars and in the ownership of land led to a demand for better, more accurate maps and the more accurate determination of boundaries. Both requiring surveying and the instruments needed for surveying. In 1524 Peter Apian (1495–1552) a product of the 2nd Viennese school of mathematics published his Cosmographia in Ingolstadt, a textbook for astronomy, astrology, cartography and surveying.


The Cosmographia went through more than 30 expanded, updated editions, but all of which, apart from the first, were edited and published by Gemma Frisius (1508–1555) in Louvain. In 1533 in the third edition Gemma Frisius added an appendix Libellus de locorum describendum ratione, the first complete description of triangulation, the central method of cartography and surveying down to the present, which, of course in dependent on scientific instruments.


In 1533 Apian’s Instrumentum Primi Mobilis 


was published in Nürnberg by Johannes Petreius (c. 1497–1550) the leading scientific publisher in Europe, who would go on ten years later to publish, Copernicus’ De revolutionibus, which was a high point in the astronomical revival.

All of this constitutes a clear indication of the steep rise in the demand for scientific instruments in the hundred years between 1450 and 1550; a demand that the metal workers of Nürnberg were more than happy to fill. In the period between Regiomontanus and the middle of the 16th century Nürnberg also became a home for some of the leading mathematici of the period, mathematicians, astronomers, astrologers, cartographers, instrument makers and globe makers almost certainly, like Regiomontanus, at least partially attracted to the city by the quality and availability of the scientific instruments.  Some of them are well known to historians of Renaissance science, Erhard Etzlaub, Johannes Werner, Johannes Stabius (not a resident but a frequent visitor), Georg Hartmann, Johannes Neudörffer and Johannes Schöner.**

There is no doubt that around 1500, Nürnberg was one of the major producers and exporters of scientific instruments and I hope that I have shown above, in what is little more than a sketch of a fairly complex process, that this owed very little to science but much to the general geo-political and economic developments of the first 500 years of the city’s existence.

WI12; WI33 WI3; WI2; WI30;

One of the most beautiful sets on instruments manufactured in Nürnberg late 16th century. Designed by Johannes Pretorius (1537–1616), professor for astronomy at the Nürnberger University of Altdorf and manufactured by the goldsmith Hans Epischofer (c. 1530–1585) Germanische National Museum


**for an extensive list of those working in astronomy, mathematics, instrument making in Nürnberg (542 entries) see the history section of the Astronomie in Nürnberg website, created by Dr Hans Gaab.












Filed under Early Scientific Publishing, History of Astronomy, History of Cartography, History of Mathematics, History of Navigation, History of science, History of Technology, Renaissance Science

The Renaissance Mathematicus Christmas Trilogies explained for newcomers


Being new to the Renaissance Mathematicus one might be excused if one assumed that the blogging activities were wound down over the Christmas period. However, exactly the opposite is true with the Renaissance Mathematicus going into hyper-drive posting its annual Christmas Trilogy, three blog posts in three days. Three of my favourite scientific figures have their birthday over Christmas–Isaac Newton 25thDecember, Charles Babbage 26thDecember and Johannes Kepler 27thDecember–and I write a blog post for each of them on their respective birthdays. Before somebody quibbles I am aware that the birthdays of Newton and Kepler are both old style, i.e. on the Julian Calendar, and Babbage new style, i.e. on the Gregorian Calendar but to be honest, in this case I don’t give a shit. So if you are looking for some #histSTM entertainment or possibly enlightenment over the holiday period the Renaissance Mathematicus is your number one address. In case the new trilogy is not enough for you:

The Trilogies of Christmas Past

Christmas Trilogy 2009 Post 1

Christmas Trilogy 2009 Post 2

Christmas Trilogy 2009 Post 3

Christmas Trilogy 2010 Post 1

Christmas Trilogy 2010 Post 2

Christmas Trilogy 2010 Post 3

Christmas Trilogy 2011 Post 1

Christmas Trilogy 2011 Post 2

Christmas Trilogy 2011 Post 3

Christmas Trilogy 2012 Post 1

Christmas Trilogy 2012 Post 2

Christmas Trilogy 2012 Post 3

Christmas Trilogy 2013 Post 1

Christmas Trilogy 2013 Post 2

Christmas Trilogy 2013 Post 3

Christmas Trilogy 2014 Post 1

Christmas Trilogy 2014 Post 2

Christmas Trilogy 2014 Post 3

Christmas Trilogy 2015 Post 1

Christmas Trilogy 2015 Post 2

Christmas Trilogy 2015 Post 3

Christmas Trilogy 2016 Post 1

Christmas Trilogy 2016 Post 2

Christmas Trilogy 2016 Post 3

Christmas Trilogy 2017 Post 1

Christmas Trilogy 2017 Post 2

Christmas Trilogy 2017 Post 3

Christmas Trilogy 2018 Post 1

Christmas Trilogy 2018 Post 2

Christmas Trilogy 2018 Post 3






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Filed under History of Astronomy, History of Mathematics, History of Physics, History of science, History of Technology, Uncategorized

Mathematical aids for Early Modern astronomers.

Since its very beginnings in the Fertile Crescent, European astronomy has always involved a lot of complicated and tedious mathematical calculations. Those early astronomers described the orbits of planets, lunar eclipses and other astronomical phenomena using arithmetical or algebraic algorithms. In order to simplify the complex calculations needed for their algorithms the astronomers used pre-calculated tables of reciprocals, squares, cubes, square roots and cube roots.


Cuniform reciprocal table Source

The ancient Greeks, who inherited their astronomy from the Babylonians, based their astronomical models on geometry rather than algebra and so needed other calculation aids. They developed trigonometry for this work based on chords of a circle. The first chord tables are attributed to Hipparkhos (c. 190–c. 120 BCE) but they did not survive. The oldest surviving chord tables are in Ptolemaeus’ Mathēmatikē Syntaxis written in about 150 CE, which also contains a detailed explanation of how to calculate such a table in Chapter 10 of Book I.


Ptolemaeus’ Chord Table taken from Toomer’s Almagest translation. The 3rd and 6th columns are the interpolations necessary for angles between the given ones

Greek astronomy travelled to India, where the astronomers replaced Ptolemaeus’ chords with half chords, that is our sines. Islamic astronomers inherited their astronomy from the Indians with their sines and cosines and the Persian astronomer Abū al-Wafāʾ (940–998 CE) was using all six of the trigonometrical relations that we learnt at school (didn’t we!) in the tenth century.


Abū al-Wafāʾ Source: Wikimedia Commons

Astronomical trigonometry trickled slowly into medieval Europe and Regiomontanus (1536–1576)  (1436–1476) was the first European to produce a comprehensive work on trigonometry for astronomers, his De triangulis omnimodis, which was only edited by Johannes Schöner and published by Johannes Petreius in 1533.

Whilst trigonometry was a great aid to astronomers calculating trigonometrical tables was time consuming, tedious and difficult work.

A new calculating aid for astronomers emerged during the sixteenth century, prosthaphaeresis, by which, multiplications could be converted into additions using a series of trigonometrical identities:

Prosthaphaeresis appears to have first been used by Johannes Werner (1468–1522), who used the first two formulas with both sides multiplied by two.

However Werner never published his discovery and it first became known through the work of the itinerant mathematician Paul Wittich (c. 1546–1586), who taught it to both Tycho Brahe (1546–1601) on his island of Hven and to Jost Bürgi (1552–1632) in Kassel, who both developed it further. It is not known if Wittich learnt the method from Werner’s papers on one of his visits to Nürnberg or rediscovered it for himself. Bürgi in turn taught it to Nicolaus Reimers Baer (1551–1600) in in exchange translated Copernicus’ De revolutionibus into German for Bürgi, who couldn’t read Latin. This was the first German translation of De revolutionibus. As can be seen the method of prosthaphaeresis spread throughout Europe in the latter half of the sixteenth century but was soon to be superceded by a superior method of simplifying astronomical calculations by turning multiplications into additions, logarithms.

As is often the case in the histories of science and mathematics logarithms were not discovered by one person but almost simultaneously, independently by two, Jost Bürgi and John Napier (1550–1617) and both of them seem to have developed the idea through their acquaintance with prosthaphaeresis. I have already blogged about Jost Bürgi, so I will devote the rest of this post to John Napier.


John Napier, artist unknown Source: Wikimedia Commons

John Napier was the 8th Laird of Merchiston, an independently owned estate in the southwest of Edinburgh.


Merchiston Castle from an 1834 woodcut Source: Wikimedia Commons

His exact date of birth is not known and also very little is known about his childhood or education. It is assumed that he was home educated and he was enrolled at the University of St. Andrews at the age of thirteen. He appears not to have graduated at St. Andrews but is believed to have continued his education in Europe but where is not known. He returned to Scotland in 1571 fluent in Greek but where he had acquired it is not known. As a laird he was very active in the local politics. His intellectual reputation was established as a theologian rather than a mathematician.

It is not known how and when he became interested in mathematics but there is evidence that this interest was already established in the early 1570s, so he may have developed it during his foreign travels. It is thought that he learnt of prosthaphaeresis through John Craig (d. 1620) a Scottish mathematician and physician, who had studied and later taught at Frankfurt an der Oder, a pupil of Paul Wittich, who knew Tycho Brahe. Craig returned to Edinburgh in 1583 and is known to have had contact with Napier. The historian Anthony à Wood (1632–1695) wrote:

one Dr. Craig … coming out of Denmark into his own country called upon John Neper, baron of Murcheston, near Edinburgh, and told him, among other discourses, of a new invention in Denmark (by Longomontanus as ’tis said) to save the tedious multiplication and division in astronomical calculations. Neper being solicitous to know farther of him concerning this matter, he could give no other account of it than that it was by proportionable numbers. [Neper is the Latin version of his family name]

Napier is thought to have begum work on the invention of logarithms about 1590. Logarithms exploit the relation ship between arithmetical and geometrical series. In modern terminology, as we all learnt at school, didn’t we:

Am x An = Am+n

Am/An = Am-n

These relationships were discussed by various mathematicians in the sixteenth century, without the modern notation, in particularly by Michael Stefil (1487–1567) in his Arithmetica integra (1544).


Michael Stifel Source: Wikimedia Commons


Michael Stifel’s Arithmetica Integra (1544) Source: Wikimedia Commons

What the rules for exponents show is that if one had tables to convert all numbers into powers of a given base then one could turn all multiplications and divisions into simple additions and subtractions of the exponents then using the tables to covert the result back into a number. This is what Napier did calling the result logarithms. The methodology Napier used to calculate his tables is too complex to deal with here but the work took him over twenty years and were published in his Mirifici logarithmorum canonis descriptio… (1614).


Napier coined the term logarithm from the Greek logos (ratio) and arithmos (number), meaning ratio-number. As well as the logarithm tables, the book contains seven pages of explanation on the nature of logarithms and their use. A secondary feature of Napier’s work is that he uses full decimal notation including the decimal point. He was not the first to do so but his doing so played an important role in the acceptance of this form of arithmetical notation. The book also contains important developments in spherical trigonometry.

Edward Wright  (baptised 1561–1615) produced an English translation of Napier’s Descriptio, which was approved by Napier, A Description of the Admirable Table of Logarithmes, which was published posthumously in 1616 by his son Samuel.


Gresham College was quick to take up Napier’s new invention and this resulted in Henry Briggs (1561–1630), the Gresham professor of geometry, travelling to Edinburgh from London to meet with Napier. As a result of this meeting Briggs, with Napier’s active support, developed tables of base ten logarithms, Logarithmorum chilias prima, which were publish in London sometime before Napier’s death in 1617.


He published a second extended set of base ten tables, Arithmetica logarithmica, in 1624.


Napier’s own tables are often said to be Natural Logarithms, that is with Euler’s number ‘e’ as base but this is not true. The base of Napierian logarithms is given by:

NapLog(x) = –107ln (x/107)

Natural logarithms have many fathers all of whom developed them before ‘e’ itself was discovered and defined; these include the Jesuit mathematicians Gregoire de Saint-Vincent (1584–1667) and Alphonse Antonio de Sarasa (1618–1667) around 1649, and Nicholas Mercator (c. 1620–1687) in his Logarithmotechnia (1688) but John Speidell (fl. 1600–1634), had already produced a table of not quite natural logarithms in 1619.


Napier’s son, Robert, published a second work by his father on logarithms, Mirifici logarithmorum canonis constructio; et eorum ad naturales ipsorum numeros habitudines, posthumously in 1619.


This was actually written earlier than the Descriptio, and describes the principle behind the logarithms and how they were calculated.

The English mathematician Edmund Gunter (1581–1626) developed a scale or rule containing trigonometrical and logarithmic scales, which could be used with a pair of compasses to solve navigational problems.


Table of Trigonometry, from the 1728 Cyclopaedia, Volume 2 featuring a Gunter’s scale Source: Wikimedia Commons

Out of two Gunter scales laid next to each other William Oughtred (1574–1660) developed the slide rule, basically a set of portable logarithm tables for carry out calculations.

Napier developed other aids to calculation, which he published in his Rabdologiae, seu numerationis per virgulas libri duo in 1617; the most interesting of which was his so called Napier’s Bones.


These are a set of multiplication tables embedded in rods. They can be used for multiplication, division and square root extraction.


An 18th century set of Napier’s bones Source: Wikimedia Commons

Wilhelm Schickard’s calculating machine incorporated a set of cylindrical Napier’s Bones to facilitate multiplication.

The Swiss mathematician Jost Bürgi (1552–1632) produced a set of logarithm tables independently of Napier at almost the same time, which were however first published at Kepler’s urging as, Arithmetische und Geometrische Progress Tabulen…, in 1620. However, unlike Napier, Bürgi delivered no explanation of the how his table were calculated.


Tables of logarithms became the standard calculation aid for all those making mathematical calculations down to the twentieth century. These were some of the mathematical tables that Babbage wanted to produce and print mechanically with his Difference Engine. When I was at secondary school in the 1960s I still carried out all my calculations with my trusty set of log tables, pocket calculators just beginning to appear as I transitioned from school to university but still too expensive for most people.


Not my copy but this is the set of log tables that accompanied me through my school years

Later in the late 1980s at university in Germany I had, in a lecture on the history of calculating, to explain to the listening students what log tables were, as they had never seen, let alone used, them. However for more than 350 years Napier’s invention served all those, who needed to make mathematical calculations well.














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

Revealing the secrets of the fire-using arts

During the Middle Ages it was common practice for those working in the crafts to keep the knowledge of their trades secret, masters passing on those secrets orally to new apprentices. This protection of trade secrets, perhaps, reached a peak during the Renaissance in the glassmaking centre of Venice, where anybody found guilty of revealing the secrets of the glassmaking was sentenced to death. Although there were in some crafts manuscripts, which made it into print, describing the work processes involved in the craft these were of very limited distribution. All of this began to change with the invention of moving type book printing. Over the sixteenth and seventeenth centuries printed books began to appear describing in detail the work processes of various crafts. I have already written a post about one such book, De re metallica by Georgius Agricola (1494–1555). However, Agricola’s book was not the first printed book on metallurgy that honour goes to the Pirotechnia of Vannoccio Biringuccio published posthumously in Italian in 1540. Agricola was well aware of Biringuccio’s book and even plagiarised sections of it in his own work.


Title page, De la pirotechnia, 1540, Source: Science History Museum via Wikipedia Commons

Whereas Agricola was himself not a miner or metal worker but rather a humanist physician, whose knowledge of the medieval metallurgical industry was based on observation and questioning of those involved, Biringuccio, as we will see, spent his whole life engaged in one way or another in that industry and his book was based on his own extensive experiences.

Born in Siena 20 October 1480 the son of Lucrezia and Paolo Biringuccio, an architect.


Siena 1568

As a young man Vannoccio travelled throughout Italy and Germany studying metallurgical operations. In Siena he was closely associated with the ruling Petrucci family and after having run an iron mine and forge for Pandolfo Petrucci, he was appointed to a public position at the arsenal and in 1513 director of the mint.


Petrucci coat of arms Source: Wikimedia Commons

He was exiled from Siena in 1516 after the Petruccis fell from power and undertook further travels throughout Italy and visited Sicily in 1517. In 1523 the Petruccis were reinstated and Vannoccio returned to Siena and to his position in the arsenal. In 1526 the Petruccis fell from power again and he was once again forced to leave his hometown. He worked in both the republics of Venice and Florence casting cannons and building fortifications. In 1531 in a period of political peace he returned once more to Sienna, where he was appointed a senator, and architect and director of building construction. Between 1531 and 1535 he cast cannons and constructed fortification in both Parma and Venice. In 1536 he was offered a job in Rome and after some hesitation accepted the post of head of the papal foundry and director of papal munitions. It is not known when or where he died but there is documentary evidence that he was already dead on 30 April 1539.

His Pirotechnia was first published posthumously in Venice in 1540, it was printed by Venturino Roffinello, published by Curtio Navo and dedicated to Bernardino di Moncelesi da Salo. Bernardino is mentioned both in the book’s preface as well as in the text. The Pirotechnia consists of ten books, each one dealing with a separate theme in the world of Renaissance metallurgy, transitioning from the wining of metal ores, over their smelting to the use of the thus produced materials in the manufacture of metal objects and dealing with a whole host of side topic on the way. Although by no means as lavishly illustrated as De re metallica, the book contains 84 line drawings** that are as important in imparting knowledge of the sixteenth century practices as the text.

Book I, is titled Every Kind of Mineral in General, after a general introduction on the location of ores it goes on the deal separately with the ores of gold, silver, copper, lead, tin and iron and closes with the practice of making steel and of making brass.



Book II continues the theme with what Biringuccio calls the semi-minerals an extensive conglomeration of all sorts of things that we wouldn’t necessarily call minerals. Starting with quicksilver he moves on to sulphur then antimony, marcasite (which includes all the sulphide minerals with a metallic luster), vitriol, rock alum, arsenic, orpiment and realgar.



This is followed by common salt obtained from mine or water and various other salts in general then calamine Zaffre and manganese. The book now takes a sharp turn as Biringuccio deals with the loadstone and its various effects and virtues. His knowledge in obviously not first hand as he repeats the standard myths about loadstones losing their power and virtue in the presence of diamonds, goat’s milk and garlic juice. He now move on to, ochre, bole, emery, borax, azure and green azure. Pointing out that many of the things he has dealt with are rocks rather than metals he now introduces rock crystal and all important gems in general before closing the book with glass.


Book III covers the assaying and smelting metal ores concentring on silver, gold and copper.





Book IV continues with a related theme, the various methods for separating gold from silver.



Having covered separation of gold and silver Book V covers the alloys of gold, silver, copper, lead and tin.

Following the extraction of metals, their assays, separation and alloys, Book VI turns to practical uses of metals: the art of casting in general and particular.







Book VII the various methods of melting metals.







Having dealt with the casting of bells and cannons in Book VII, Book VIII deals the small art of casting.


Book IX is a bit of a mixed bag titled, Concerning the Procedure of Various Operations of Fire. The book opens with a very short chapter on alchemy. Biringuccio has already dealt with alchemical transmutation fairy extensively in Book I when discussing the production of gold. He doesn’t believe in it: These men [alchemists] in order to arrive at such a port have equipped their vessels with sails and hard-working oarsmen and have sailed with guiding stars, trying every possible course, and, finally submerged in the impossible (according to my belief) not one of them to my knowledge has yet come to port. In Book XI he acknowledges that although transmutation doesn’t work, alchemists have developed many positive things: …it is surely a fine occupation, since in addition to being very useful to human need and convenience, it gives birth every day to new and splendid effects such as the extraction of medicinal substances, colours and perfumes, and an infinite number of compositions of things. It is known that many arts have issued solely from it; indeed, without it or its means it would have been impossible for them ever to have been discovered by man except through divine revelation.The next chapter deal briefly with sublimation and very extensively with distillation both of which he acknowledges are products of the alchemists.




He now takes a sharp turn left with a chapter on Discourse and Advice on How to Operate a Mint Honestly and with Profit. This is followed with chapters on goldsmith, coppersmith, ironsmith and pewterer work, leading on to chapters on wire drawing, preparing gold for spinning, removing gold from silver and other gilded objects, and the extraction of every particle of gold and silver from slags of ore.



The book closes with making mirrors from bell metal and three chapters on working with clay.


Book X closes out Biringuccio’s deliberations with essays on making saltpetre and gunpowder, then moving on to the uses of gunpowder in gunnery, military mining, and fireworks, the later in both military and civil circumstances.



Biringuccio’s efforts proved successful with Italian editions of the book appearing in 1540 (Sienna), 1550 (Venetia), 1558/9 (Venegia), 1559 (Venetia), 1678 (Bologna), and 1914 (Barese). French editions appeard in 1556 (Paris), 1572 (Paris), 1627 (Rouen), and 1856 (Paris). A German edition appeared in 1925 (Braunschweig). There were only partial translation into English in 1555 (London) and 1560 (London). The first full English translation was made by Martha Teach Gnudi & Cyril Stanley Smith with notes and an introduction in 1941 (New Haven), which was republished by Dover Books in New York in 1990. It is the Dover edition that forms the basis of this blog post.

Biringuccio’s Pirotechnia is an important publication in the histories of technology, metallurgy, inorganic chemistry and the crafts and trades in general and deserves to be much better known.

**I have only chosen a selection of the drawings. On some subjects such as the use of bellows Biringuccio brings wholes rows of illustrations to demonstrate the diverse methods used.








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

A book for lunatics

The world has currently gone moon crazy, because it is now fifty years since a couple of American went for a walk on the moon. This has meant the usual flood of books, journal, magazine and newspaper articles, blog post and, Twitter and Facebook postings that now accompany any such #histSTM anniversary that is considered by the media world to be significant enough. With the following statement I shall probably lose half of my Twitter following overnight but personally I don’t find this particular anniversary especially interesting. I do have one peculiar biographical quirk in that I don’t think I actually watched that first moon landing; at least I have absolutely no memory of having done so. The last weeks of the school year 1968–69 were a highly emotional time for me. I had just been expelled from boarding school but was still living there as my fees were paid up to the end of the school year and my parents were away on sabbatical in Indonesia. Somehow all of that was more important in my life than some guys going for a walk on the moon.

Although I have skimmed the occasional newspaper/magazine/Internet article I have not and will not bother to buy and read any of the apparently X zillion books that have been thrown onto the market to celebrate the occasion. I will admit to having treated myself to Ewen A. Whitaker’s Mapping and Naming the MoonA History of Lunar Cartography and Nomenclature (CUP, ppb. 2003), which actually has little to do with the actual anniversary. I have however acquired and read one book written specifically for the anniversary Oliver Morton’s The Moon: A History for the Future (The Economist Books, 2019). I got this for free because I read and suggested corrections for those bits of the book dealing with the Early Modern Period. Although, I saved the author from making, what I consider to be a serious error but which the normal reader probably wouldn’t even have noticed, I think my contribution to the final product was so minimal that I can safely review it without fear of personal bias.


We’ll start at the top with the very simple statement; this is truly an excellent book. I would be very tempted to say, if you only read one book on the moon this year then you could do worse than choose this one. However, not having read any of the others, this would not be very fair to the other moon book authors. Back to the praise, Morton’s book is a wonderful literary tour de force, which is also incredibly informative. He combines the histories of astronomy, technology, the moon landings and science fiction to create a stimulating potpourri of lunar lore and selenology.

The book is divided into eight sections rather than chapters, each of which deals with a different aspect of humanity’s relationship with the Moon. Section I introduces the reader to the phenomenon of earthshine, the light reflected from the Earth that illuminates those parts of the Moon not lit by the Sun, both its discovery in the Early Modern Period and its use in modern times for scientific experiments. Section II deals with studies of the Moon’s appearance from the High Middle Ages down to the twentieth century. Section III takes us along the path of the development of rocketry up to Apollo and then with Armstrong, Aldrin and Collins on Apollo 11 to that first ever moon landing. Section IV takes a look at the various theories to explain the origins of the Moon and its geology. Section V deals with the end or better said the collapse of the Apollo program and then over the years the various suggestions for economically viable schemes to return to the Moon, here Morton demonstrates his strengths as a narrator. Although he is obviously a space fan he carefully details why such schemes were largely unrealistic or impractical. Section VI examines the various schemes currently being developed for a real return. Having got there, section VII discusses what to do when we get there if we do go back. Section VIII looks at negative literary depictions of the Moon illustrating rather nicely that maybe the Moon isn’t such an attractive place to visit.

This listing of the main themes of each section doesn’t do Morton’s inventiveness justice. He weaves lots of side topics into the weft of his main narratives taking his readers down many highways and byways, leaving the readers with the impression that he has consumed a vast library of lunar information, an impression strengthened by the extensive bibliography.  His real achievement is to pack so much fascinating information into so few pages, whilst retaining a wonderful light readable style. His book is both an encyclopaedia and a work of art.




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

Renaissance Heavy Metal

One of the most fascinating and spectacularly illustrated Renaissance books on science and technology is De re metallica by Georgius Agricola (1494–1555). Translated into English the author’s name sounds like a figure from a game of happy families, George the farmer. In fact, this is his name in German, Georg Pawer, in modern German Bauer, which means farmer or peasant or the pawn in chess. Agricola was, however, anything but a peasant; he was an extraordinary Renaissance polymath, who is regarded as one of the founders of modern mineralogy and geology.


Georg Bauer was born in Glauchau on 24 March 1494, the second of seven children, to Gregor Bauer (born between 1518 and 1532) a wealthy cloth merchant and dyer. He was initially educated at the Latin school in Zwickau and attended the University of Leipzig, where he studied theology, philosophy and philology from 1514 to 1517. From 1518 to 1522 he worked as deputy director and then as director of schools in Zwickau. In 1520 he published his first book, a Latin grammar. The academic year 1522-23 he worked as a lecturer at the University of Leipzig. From 1523 to 1526 he studied medicine, philosophy and the sciences at various Northern Italian university graduating with a doctorate in medicine. In Venice he worked for a time for the Manutius publishing house on their edition of the works of Galen.

From 1527 to 1533 Agricola worked as town physician in St. Joachimsthal*, today Jáchymov in the Czech Republic. In those days Joachimsthal was a major silver mining area and it is here that Agricola’s interest in mining was ignited.


Silver mining in Joachimsthal (1548) Source: Wikimedia Commons

In 1530 he issued his first book on mining, Bermannus sive de re metallica, published by the Froben publishing house in Basel. It covered the search for metal ores, the mining methods, the legal framework for mining claims, the transport and processing of the ores. Bermannus refers to Lorenz Bermann, an educated miner, who was the principle source of his information. The book contains an introductory letter from Erasmus, who worked as a copyeditor for Froben during his years in Basel.

In 1533 he published a book on Greek and Roman weights and measures, De mensuris et ponderibus libri V, also published Froben in Basel.


From 1533 to his death in 1555 he was town physician in Chemnitz. He was also district historian for the Saxon aristocratic dynasty. From 1546 onwards he was a member of the town council and served as mayor in 1546, 1547, 1551 and 1553. In Chemnitz he also wrote a book on the plague, De peste libri tres, his only medical book,  as ever published by Froben in 1554.


Source: Internet Archive

Having established himself as an expert on mining with the Bermannus, Agricola devoted more than twenty years to studying and writing about all aspects of mining and the production of metals. He wrote and published a series of six books on the subject between 1546 and 1550, all of them published by Froben.

De ortu et causis subterraneorum libri V, Basel 1546

The origin of material within the earth

De natura eorum, quae effluunt ex terra, Basel 1546

The nature of the material extruded out of the earth

De veteribus et novis metallis libri II, Basel 1546

Ore mining in antiquity and in modern times

De natura fossilium libri X, Basel 1546

The nature of fossils whereby fossils means anything found in the earth and is as much a textbook of mineralogy

De animantibus subterraneis liber, Basel 1549

The living underground

De precio metallorum et monetis liber III, 1550

On precious metals and coins

At the same time he devoted twenty years to composing and writing his magnum opus De re metallica, which was published posthumously in 1556 by Froben in Basel, who took six years to print the book due to the large number of very detailed woodcut prints with which the book is illustrated. These illustrations form an incredible visual record of Renaissance industrial activity. They are also an impressive record of late medieval technology. Agricola’s pictures say much more than a thousand words.

De re metallicahas twelve books or as we would say chapters. What distinguishes Agricola’s work from all previous writings on mineralogy and geology is the extent to which they are based on empirical observation rather than philosophical speculation. Naturally this cannot go very far as it would be several hundred years before the chemistry was developed necessary to really analyse mineralogical and geological specimens but Agricola’s work was a major leap forward towards a modern scientific analysis of metal production.


Book I: Discusses the industry of mining and ore smelting

Book II: Discusses ancient mines, finding minerals and metals and the divining rod

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Book III: Discusses mineral veins and seams and plotting with the compass

Book IV: Discusses the determination of mine boundaries and mine organisation

Book V: Discusses the principles of mining, the metals, ancient mining and mine surveying

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Book VI: Discusses mining tools and equipment, hoists and pumps, ventilation and miners’ diseases

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Book VII: Discusses assaying ores and metals and the touchstone

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Book VIII: Discusses preparing ores for roasting, crushing and washing and recovering gold by mercury

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Book IX: Discusses ores and furnaces for smelting copper, iron and mercury and the use of bellows

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Book X: Discusses the recovery of precious metals from base metals as well as separating gold and silver by acid

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Book XI: Discusses the recovery of silver from copper by liquidation as well as refining copper

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Book XII: Discusses salts, solvents, precipitates, bitumen and glass

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Agricola’s wonderfully illustrated volume became the standard reference work on metal mining and production for about the next two hundred years. The original Latin edition appeared in Basel in 1556 and was followed by a German translation in 1557, which was in many aspects defective but remained unchanged in two further editions. There were further Latin editions published in 1561, 1621, and 1657 and German ones in 1580, and 1621, with an improved German translation in 1928 and 1953. There was an Italian translation published in 1563.

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Of peculiar interest is the English translation. This was first published in 1912 in London, the work of American mining engineer Herbert Hoover (1874–1964) and his wife the geologist Lou Henry (1874–1944). A second edition was published in 1950. Hoover is, of course, better know as the 31stPresident of the USA, who was elected in 1928 and served from 1929–1933.


Herbert Hoover in his 30s while a mining engineer Source: Wikimedia Commons


Lou Henry, circa 1930 Source: Wikimedia Commons

Agricola’s tome also represents an important development in the history of trades and professions. Before De re metallicaknowledge of trades and crafts was past from master to apprentice verbally and kept secret from those outside of guild, often on pain of punishment. Agricola’s book is one of the first to present the methods and secrets of a profession in codified written form for everyone to read, a major change in the tradition of knowledge transfer.

*A trivial but interesting link exists between St. Joachimsthal and the green back. A silver coin was produced in St. Joachimsthal, which was known as the Joachimsthaler. This got shortened in German to thaler, which mutated in Dutch to daalder or daler and from there in English to dollar.

All illustrations from De re metallica are taken from Bern Dibner, Agricola on Metals, Burndy Library, 1958






Filed under Early Scientific Publishing, History of Technology, Mediaeval Science, Renaissance Science

The Jesuit Mirror Man

Although the theory that a curved mirror can focus an image was already known to Hero of Alexandria in antiquity and also discussed by Leonardo in his unpublished writings; as far as we know, the first person to attempt to construct a reflecting telescope was the Italian Jesuit Niccolò Zucchi.


Niccolò Zucchi Source: Wikimedia Commons

Niccolò Zucchi, born in Parma 6 December 1586, was the fourth of eight children of the aristocrat Pierre Zucchi and his wife Francoise Giande Marie. He studied rhetoric in Piacenza and philosophy and theology in Parma, probably in Jesuit colleges. He entered the Jesuit order as a novice 28 October 1602, aged 16. Zucchi taught mathematics, rhetoric and theology at the Collegio Romano and was then appointed rector of the new Jesuit College in Ravenna by Cardinal Alessandro Orsini, who was also a patron of Galileo.

In 1623 he accompanied Orsini, the Papal legate, on a visit to the court of the Holy Roman Emperor Ferdinand II in Vienna. Here he met and got to know Johannes Kepler the Imperial Mathematicus. Kepler encouraged Zucchi’s interest in astronomy and the two corresponded after Zucchi’s return to Italy. Later when Kepler complained about his financial situation, Zucchi sent him a refracting telescope at the suggestion of Paul Guldin (1577–1643) a Swiss Jesuit mathematician, who also corresponded regularly with Kepler. Kepler mentions this gift in his Somnium. These correspondences between Kepler and leading Jesuit mathematicians illustrate very clearly how the scientific scholars in the early seventeenth century cooperated with each other across the religious divide, even at the height of the Counter Reformation.

Zucchi’s scientific interests extended beyond astronomy; he wrote and published two books on the philosophy of machines in 1646 and 1649. His unpublished Optica statica has not survived. He also wrote about magnetism, barometers, where he a good Thomist rejected the existence of a vacuum, and was the first to demonstrate that phosphors generate rather than store light.

Today, however Zucchi is best remember for his astronomy. He is credited with being the first, together with the Jesuit Daniello Bartoli (1608–1685), to observe the belts of Jupiter on 17 May 1630.  He reported observing spots on Mars in 1640. These observations were made with a regular Galilean refractor but it is his attempt to construct a reflecting telescope that is most fascinating.

In his Optica philosophia experimentis et ratione a fundamentis constituta published in 1652 he describes his attempt to create a reflecting telescope.


Optica philosophia title page Source: Linder Hall Library

As I said at the beginning, and have described in greater detail here, the principle that one could create an image with a curved mirror had been known since antiquity. Zucchi tells us that he replaced the convex objective lens in a Galilean telescope with bronze curved mirror. He tried viewing the image with the eyepiece, a concave lens looking down the tube into the mirror. He had to tilt the tube so as not to obstruct the light with his head. He was very disappointed with the result as the image was just a blur, although as he said the mirror was, “ab experto et accuratissimo artifice eleboratum nactus.” Or in simple words, the mirror was very well made by an expert.


Optica philosophia frontispiece

Zucchi had stumbled on a problem that was to bedevil all the early attempts to construct a reflecting telescope. Mirror that don’t distort the image are much harder to grind and polish than lenses. (The bending of light in a lens diminishes the effect of imperfections, whereas a mirror amplifies them). The first to solve this problem was Isaac Newton, proving that he was as skilled a craftsman as he was a great thinker. However, it would be more that fifty years before John Hadley could consistently repeat Newton’s initial success.

All the later reflecting telescope models had, as well as their primary mirrors, a secondary mirror at the focal point that reflected the image either to the side (a Newtonian), or back through the primary mirror (a Gregorian or a Cassegrain) to the eyepiece; the Zucchi remained the only single mirror telescope in the seventeenth century.

In the eighteenth century William Herschel initially built and used Newtonians but later he constructed two massive reflecting telescopes, first a twenty-foot and then a second forty-foot instrument.


Herschel’s Grand Forty feet Reflecting Telescopes A hand-coloured illustration of William Herschel’s massive reflecting telescope with a focal length of forty feet, which was erected at his home in Slough. Completed in 1789, the telescope became a local tourist attraction and was even featured on Ordnance Survey maps. By 1840, however, it was no longer used and was dismantled, although part of it is now on display at the Royal Observatory, Greenwich. This image of the telescope was engraved for the Encyclopedia Londinensis in 1819 as part of its treatment of optics. Herschel’s Grand Forty feet Reflecting Telescopes Source: Wikimedia Commons

These like Zucchi’s instrument only had a primary mirror with Herschel viewing the image with a hand held eyepiece from the front of the tube. As we name telescopes after their initial inventors Herschel giant telescopes are Zucchis, although I very much doubt if he even knew of the existence of his Jesuit predecessor, who had died at the grand old age of eighty-three in 1670.



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