Tag: History

Apr 22 2011

L’Académie des Sciences

ColbertPresents

I’ve written a number of times on the Royal Society, Britain’s leading and oldest learned society, often via the medium of book reviews but also through a bit of data wrangling. This post concerns the Académie des Sciences, the French equivalent of the Royal Society. It has gone through several evolutions, and is has been one of five academies inside the Institut de France since its founding in 1795. As a physical scientist the names of many members of the Académie are familiar to me; names such as Coulomb, Lagrange, Laplace, Lavoisier, Fourier, Fresnel, Poisson, Biot, Cassini, Carnot …

The reason I’m interested in scientific societies is that, as a practitioner, I know they are part of the way science works – they are the conduit by which scientists* interact within a country and how they interact between countries. They are a guide to who’s hot and who’s not in science at a particular moment in time, with provisos for the politics of the time. As I have remarked before much of the “history” taught to scientists comes in the form of Decorative Anecdotes of Famous Scientists, this is my attempt to go beyond that narrow view.

The Académie des Sciences was founded in France in 1666 only a few years after the Royal Society which formally started in 1660. It appears to have grown from the group of correspondents and visitors to Marin Mersenne. In contrast to the Royal Society it was set up as a branch of government, directed by Jean-Baptiste Colbert who had proposed the idea to Louis XIV. The early Academy ran without any statutes until 1699 when it gained the Royal label. The Academy was based on two broad divisions of what were then described as mathematical sciences (astronomy, mathematics and physics) and “physical” sciences (anatomy, botany, zoology and chemistry) within these divisions were elected a number of academicians, and others of different grades. Numbers were strictly limited: in 1699 there were 70 members and even now there are only 236. Unlike the Royal Society, funded by member subscriptions, the Academy was funded by government – giving a number of generous pensions to senior academicians to conduct their scientific work.

The Academy avoided discussion of politics and religion, echoing the founding principles of the Royal Society, and was explicit in making links to foreign academics giving them the formal status of correspondent. This political neutrality was sustained through the French Revolution: although the Academy was dissolved for a few years at the height of the Terror and was subsequently reformed with essentially the same membership as before the revolution. Furthermore work on revising the French system of weights and measures carried on through the Revolution.

The Scholarly Societies Project has an overview of publications by- and about the Academy. The earliest scientific papers of the Academy appear in “Journal des Sçavans”, which commenced publication in 1665, shortly before the “Philosophical Transactions of the Royal Society” and therefore the earliest scientific journal published in Europe. From 1699 a sequence of work is published in “Histoire de l’Académie royale des sciences” until 1797.  Finally “Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences” has been published since 1835. Most of which are freely available as full-text digitized editions at Gallica (the French National Library).

The British government established the Longitude Prize in 1714, by act of parliament, to award the inventor of a simple and practical method for determining the longitude at sea. Subsequently Rouillé de Meslay invested a similar prize for the Academy, which commenced in 1720. This sequence of Academy prizes was awarded yearly to answer particular questions and alternated between subjects in the physical sciences and subjects in navigation and commerce. Those in commerce and navigation revolved around shipping: with questions on anchors, masts, marine currents and so forth. These prizes were open to all, not just members of the Academy. Subsequently the Academy became a clearing house for a whole range of prizes, these are described in more detail in “Les fondations de prix à l’Académie des sciences : 1714-1880” by E. Maindron.

In summary, although similar in their principles of supporting science, scientific communication and providing scientific support to the state and commerce the Royal Society and the Académie des Sciences differ in their internal structure and relationship with the state. The Academy being more closely aligned and funded by the state, certainly in formal terms, and rather more limited in its membership.

In common with the Royal Society the membership records of the Académie are available to play with and in common with the Royal Society they are in the form of PDF files which are a real pain to convert back into nicely structured data. I could engage in a lengthy rant on the inequities of locking up nice data in a nasty read-only format but I won’t!

Footnotes

  • Image is “Colbert présente à Louis XIV les membres de l’Académie Royale des Sciences crée en 1667” by Testelin Henri (1616-1695)
  • *Yes, Becky, I know you don’t want me to use “scientist” in reference to people living before the term was first coined in the 19th century ;-)

References

MacTutor History of Mathematics Archive is the best English language resource I’ve found on the Académie des Sciences. Winners of the Grand Prix can also be found on this site.

Apr 09 2011

Book Review: The Chemist Who Lost His Head by Vivian Grey

Portrait_of_Antoine-Laurent_Lavoisier_and_his_wife

Following on from “The Measure of All Things” my interest in Antoine Lavoisier was roused, so I went off to get a biography: “The Chemist who lost his head: The Story of Antoine Laurent Lavoisier” by Vivian Grey. This turns out to be a slim volume for the younger reader, in fact my copy appears to arrive via the Jenks East Middle School in Tulsa. As a consequence I’ve read it’s 100 or so pages in under 24 hours – that said it seems to me a fine introduction.

Antoine Lavoisier lived 1743-1794. He came from a bourgeoisie family, the son of a lawyer, and originally training as a lawyer. Subsequently he took up an education in a range of sciences. As a young man, in 1768, he bought into the Ferme Générale which was to provide him with a good income but led to his demise during the French Revolution. The Ferme Générale was the system by which the French government collected tax, essentially outsourcing the process to a private company. Taxes were collected from the so-called “Third Estate”, those who were not landed gentry or clergy. Grey indicates that Lavoisier was a benign influence at the Ferme Generale, introducing a system of pensions for farmers and doing research into improved farming methods. Through the company he met his future wife, Marie Anne Pierrette Paulz, daughter to the director of the Ferme – Antoine and Marie married in 1771 when she was 14 and he 28.

Lavoisier started his scientific career with a geological survey of France, which he conducted as an assistant to Jean Etienne Guettard between 1763 and 1767. This work was to be terminated by the King, but was completed by Guettard with Antoine Grimoald Monnet although Lavoisier was not credited. There seems to be some parallel here with William Smith’s geological map of the UK produced in 1815.

Through his geological activities Lavoisier became familiar with the mineral gypsum, found in abundance around Paris. He undertook a detailed study of gypsum which sets the theme for his future chemical research: making careful measurements of the weight of material before and after heating or exposure to water. He discovered that gypsum is hydrated: when heated it gives off water, when the dehydrated powder (now called plaster of Paris) is re-hydrated it forms a hard plaster. He wrote this work up and presented it to the Académie des Sciences – the French equivalent of the Royal Society, on which I have written repeatedly.

He was to present several papers to the Académie before being elected a member of this very elite group at the age of twenty-five, half the age of the next youngest member. Once a member he contributed to many committees advising on things such as street lighting, fire hydrants and other areas of civic interest, the Académie was directly funded by the King and more explicitly tasked with advising the government than the Royal Society was. Lavoisier was also involved in the foundation of the new metric system of measurement, which was the subject of “The Measure of All Things”. Lavoisier became one of four commissioners of gunpowder – an important role at the time. During his life he would have had contact with Joseph Banks – a long term president of the Royal Society, and also Benjamin Franklin – scientist and also United States Ambassador to France.

From a purely scientific point of view Lavoisier is best known for his work in chemistry: his approach of stoichiometry – the precise measurement of the mass of reactants in chemical reactions led to his theory of combustion which ultimately replaced the phlogiston theory. It is this replacement of phlogiston theory with the idea of oxidization that forms the foundation of Kuhn’s “paradigm shift” idea, so Lavoisier has a lot to answer for!

The portrait of Antoine and Marie Laviosier at the top of the page is by Jacques-Louis David painted ca. 1788. It strikes me as quite an intimate portrait with Marie pressed against Antoine, looking directly at the viewer whilst her husband looks at her. Marie played a significant part in the work of Lavoisier, as well as recording experiments and drawing apparatus (something that takes good understanding to do well), and assisting with correspondence and translation  she was also responsible for publishing Mémoires de Chimie after his death. She was a skilled scientist in her own right. The equipment on the table and floor can be identified: on the floor is a portable hydrometer and a glass vessel for weighing gases. On the table are a mercury gasometer, and a glass vessel container mercury – likely illustrating the properties of oxygen and nitrogen in air.

Antoine Lavoisier was executed in 1794, for his part in the Ferme Générale. His execution is attributed, at least in part to the ire of Jean-Paul Marat, who Lavoisier had earlier blocked from membership of the Académie des Sciences. It seems Lavoisier had been warned by friends that his life was in danger but appeared to think his membership of the Académie des Sciences would protect him. Ironically Jacques-Louis David also painted “The Death of Marat”.

100 pages on Lavoisier was not enough for me, I’m going for “Lavoisier” by Jean-Pierre Poirier next – some fraction of which appears to be available online, but I’m going for a paper copy.

Dec 12 2010

Nevil Maskelyne and Maiden-pap

 

SchehallionOSThis post is about Nevil Maskelyne and his 1775 measurements of the Scottish mountain, Schiehallion (know locally at the time as Maiden-pap), made in order to determine the mass of the earth. My interest in this was stimulated by the Gotthard Base Tunnel breakthrough, since the precision of drilling seemed pretty impressive (8cm horizontal, 1cm vertical see here). There’s a technical explanation of the surveying here. You may wonder how these two things are related.

It’s all about gravity: gravity is the force exerted by one object on another by virtue of their masses. The force is proportional to the masses of the two objects multiplied together divided by the distance between the centres of the two objects squared. This is Isaac Newton’s great insight, although he only applied it to the orbits of celestial bodies. The mass of an object depends on both its density and its volume.

Maskelyne measured the mass of Schiehallion by looking at the deviation of a plumb line from vertical. The problem for the Gotthard Tunnel is that, if you’re surveying underground, measuring the vertical could be hard because if the density of the rocks around you is different in different directions then a plumb-line will deviate from vertical. Actually it’s probably not a huge problem for the Gotthard Base Tunnel, the deviations Maskelyne measured were equivalent to about 1cm over the 14km length of the Gotthard Base Tunnel sections. Furthermore Maskelyne was looking at an isolated mountain: density of about 2500kgm-3 surrounded by air: density about 1kgm-3, under the Alps the variations in density will be far smaller. So we can relax – density variations probably won’t be an important effect. Although it’s interesting to note that the refraction of light by air is significant in the Gotthard Tunnel survey.

Oddly, Newton didn’t consider Maskelyne’s measurements possible, thinking that the force of gravity was insignificant for objects more mundane than worlds. However he demonstrated that for a largish mountain (3 miles high and 6 miles wide) there would be a deviation of the plumb line from vertical of “2 arc minutes”. Angles are measured in degrees (symbol:o) – there are 360o in a circle. Conventionally, if we wish to refer to fractions of a degree we talk about “minutes of arc”, there are 60 minutes in a degree; or even “seconds of arc” – there are 60 seconds of arc in 1 minute of arc. 1 second of arc is therefore 1/1,129,600th of a circle. At the time of Newton’s writing (1687) this deviation of 2 minutes of arc would have been measurable.

Why is measuring the mass of a mountain a job for the Astronomer Royal, as Nevil Maskelyne was at the time? Measuring how much a plumb line is deflected from the vertical is not simple because normally when we want to find vertical we use a plumb line (crudely a string with a weight at the end). The route out of this problem is to use the stars as a background against which to measure vertical. Maskelyne’s scheme was as follows:

  1. Find a mountain which stands isolated from it’s neighbours, with a ridge line which runs East-West and is relatively narrow in the North-South direction. This layout makes experiments and their analysis as simple as possible.
  2. Measure the deviation of a plumb line against a starry background at two points: one to the north of the ridgeline and one to the south (the plumb line will deviate in opposite directions at these two locations).
  3. Carefully survey the whole area, including the location of the the two points where you measured the plumb line and the size and shape of the mountain.
  4. Calculate the mass of the mountain from the survey of its size and shape (which gives you it’s volume) and the density of the rocks you find on the surface.
  5. From the mass of the mountain and the deviation of the plumb line you can work out the density, and therefore mass, of the earth

Measuring the location of stars to the required accuracy is a tricky business since they appear to move as the earth turns and the precision of the required measurement is pretty high. I worked out that using the 3m zenith sector (aka “telescope designed to point straight up”) the difference in pointing direction is about 0.1mm for the two stations – this was measured using a micrometer – essentially a a fine-threaded screw where main turns of the thread only add up to a small amount of progress. The ground survey doesn’t have such stringent requirements, although rather more time was spent on this survey than the stellar measurements.

Reading the 1775 paper that Maskelyne wrote is illuminating: at one point he lists the various gentleman who have visited him at his work! The work was paid for by George III who had provided money to the Royal Society for Maskelyne to measure the “transit of Venus”, some cash was left over from this exercise and the king approved it’s use for weighing the earth.

The value for the density of the earth that Maskelyne measured 235 years ago is about 20% less than the currently accepted value – not bad at all!

References

  1. The wikipedia article is good, including history and physics of the measurements (equations for those that want): http://en.wikipedia.org/wiki/Schiehallion_experiment
  2. This presentation to the Royal Philosophical Society in Glasgow in 1990 has a lot of historical background: http://www.sillittopages.co.uk/schie/schie90.html
  3. Maskelyne’s initial paper “An account of observations made on the mountain Schehallien for finding its attraction” Phil. Trans., 1775, 65, 500-542 is surprisingly readable, and provides details of the experimental measurements. The final analysis of the data was published later.
  4. Map of Schiehallion on Bing (OS mode): http://bit.ly/g1tufF

Nov 03 2010

Book review: The Scientific Revolution and the Origins of Modern Science by John Henry

ScientificRevolution_JohnHenryThe book I review in this post is “The Scientific Revolution and the Origins of Modern Science” by John Henry. In contrast to previous history books I have read this is neither popular history of science, nor original material but instead an academic text book. My first impressions are that it is a slim volume (100 pages) and contains no pictures! Since childhood I have tended towards the weightier volume, feeling it better value for money.

The Scientific Revolution is a period in European history during which the way in which science was done changed dramatically. The main action took place during the 17th century with lesser changes occurring in the 15th and 18th centuries. The Royal Society, on which I have blogged several times, plays a part in this Revolution and God’s Philosophers by James Hannam is one view of the preamble to the period.

The book starts with a brief introduction to historiography (methods of history research) of the Scientific Revolution, with a particular warning against “whiggish” behaviour: that’s to say looking back into the past and extracting from it that thread that leads to the future, ignoring all other things – the preferred alternative being to look at a period as a whole in its own terms. History as introduced by scientists is often highly whiggish.

Next up is a highlighting of the Renaissance, a period immediately prior to the Scientific Revolution wherein much renewed effort was made to learn from the Classics, the importance of the Renaissance appears to have been in initiating a break from the natural philosophy and theology taught in the universities of the time, which were teaching rather than research institutions.

The Scientific Revolution introduced two “methods of science” which differentiated it from the previous studies of natural philosophy: mathematisation and experiment. Mathematisation in that for sciences particularly relating to physics the aim became to develop a mathematical model for the physical behaviour observed. Prior to the Revolution mathematics was seen almost as a menial craft, inferior to both natural philosophy and theology which relied on logical chains of deduction to establish causes. These days mathematics has a far higher prestige, as illustrated in this xkcd comicstrip. The second element of experimentation means the use of controlled experimentation rather than pure thought to determine true facts.

One of the more surprising insights for me was the influence of magic on the developing science, very much in parallel to the influence of alchemy on the developing chemical sciences: magic was a physical equivalent. Magicians were intensely interested in the mysterious properties of physical objects and were early users of lenses and mirrors. The experience they developed in manipulating physical objects was the equivalent of the experience the alchemists gained in manipulating chemicals. Some of this thinking went forward into the new science the remaining rump of bonkers stuff left behind.

It’s very easy to glibly teach of forces and atoms to students, or perhaps blithely demonstrate the solution to an, on the face of it, tricky integral. However, we take a lot for granted: the great names of the past were at least as intelligent as more recent ones such as Einstein or Maxwell yet they struggled greatly with the idea of a force acting at a distance and so forth and that’s because these ideas are actually not obvious except in retrospect. Mechanical philosophies of Descartes and Hobbes were amongst the competing ideas for a “system of the world” ultimately supplanted by Newton.

Henry highlights that most of the participants in the Scientific Revolution were religiously devout, as were many in that time. An interesting idea taken up, but now apparently rejected, was that Puritanism was essential in driving the Scientific Revolution in Britain. Despite this, it was in this period that atheism started to appear.

A few times Henry refers to differences in emphasis between the developing new science in Britain when compared to the Continent. In Britain the emphasis was on an almost legalistic approach with purportedly bare facts presented to a jury in the form, for example, of the fellows of the Royal Society – theorising was in principle depreciated. This approach originates with Francis Bacon, a former Attorney General and experienced legal figure. On the Continent the emphasis was different, experiments were seen more as a demonstration of the correctness of a theory. The reason for this difference is laid at the door of the English Civil War, only briefly passed when the Royal Society was founded. It is argued that this largely non-confrontational style arose from a need for a bit of peace following the recent turmoil.

In sum I found this book an interesting experience: it’s very dense and heavily referenced. Popular history of science tends to revolve around individual biography and it’s nice to get some context for these lives. I’m particularly interested in following up some of the references to other European learned societies.

Further Reading

The book provides a list of handy links to online resources:

  1. Stanford Encyclopaedia of Philosophy
  2. Prof. Robert A. Hatch’s Scientific Revolution Website
  3. Prof. Paul Halsall’s Scientific Revolution Website
  4. SparkNotes Study Guide on the Scientific Revolution
  5. The Robert Boyle Project
  6. The Galileo Project
  7. The Newton Project
  8. The MacTutor History of Mathematics Archive

These all look interesting, and although not polished I’ve been using the MacTutor for many years.

Oct 14 2010

Book review: God’s Philosophers by James Hannam

God_the_Geometer I seem to be on a run of book reviewing at the moment, as I’ve indicated before these are as much for me as they are for you! This weeks contribution is on “God’s Philosophers: How the Medieval World laid the foundations of Modern Science“ by James Hannam. This book looks at the development of science, or at least a precursor to modern science, during the Middle Ages (5th-15th century). This fits in with my previous book reviewing which has gone back to the founding of the Royal Society (1662), and a little earlier with Gerard Mercator (1512-1594).

To my mind the book makes a poor start in the introduction by telling me how everything I believe about the Middle (or Dark) Ages is wrong, and so is everyone else. I’m prepared to accept that my visualisation of the Dark Ages, as being quite literally Dark with peasants fumbling around in a permanent twilight may be wrong, however this type of introduction generally leaves me believing that the writer is a conspiracy theorist!

A recurring theme of the book is how those studying natural philosophy (a convenient term for the proto-science) continually ran the risk of being accused of heresy. Hannam seems to portray the treatment of heresy as not really so bad: only 1 in 20 trials resulted in burning at the stake, there wasn’t much torture, the victim was asking for it, the church handed over the heretics to the secular authorities who carried out the most terrible punishment. This seems to treat lightly the death, by burning at the stake, of people who simply believed something different. Perhaps more insidiously anyone studying natural philosophy had to have an eye to what the church believed in case what they studied was considered to be heretical. Later Hannam’s defence turns out to be more narrowly defined: he sees himself as defending the Catholic Church against Protestants. He reserves a special ire for humanists, those in the Renaissance who had a particular fondness for studying the ancient classics.

This said, the book is a nice overview of the development of the academic life after the fall of the Roman Empire, with the early universities in Italy and France growing up as offshoots from the great cathedrals. The very earliest of these institutions taught law, and sometime later medicine although the core of early teaching was in theology. A great deal of effort was expended in recovering the work of the Ancients (Greek philosophers) this was made difficult by the absence of much knowledge of Greek in Western Europe. The Arabs had picked up much of this material in an earlier period but translated it into Arabic rather than Greek whilst Western Europe had Latin as a common scholarly language. Interest was primarily in Aristotle, although later the works of Plato were re-discovered. In some ways it’s this aspect of the Middle Age and Renaissance enterprise which is so confusing to a modern scientist. It just looks like it would be far easier, and quicker, to make a fresh start and discover things for yourself rather than dredge through ancient, partial manuscripts in ill-known languages for clues.

There are various places in the book where I can feel myself trying to shout back through the ages “Yes, yes, you’re on the right track, keep going!”. Only to see the protagonist draw back at the last minute or for their work to be subsequently ignored. Examples include Nicole Oresme (1323-1382) and his use of graphs in understanding physical ideas. Or the theory of impetus developed by Jean Buridan (~1300-1358), which is a very direct precursor of modern theories of mechanical motion. Similarly isolated sparks spoke of doing controlled experiments to test theories, and the idea that mathematics could be used to describe physical processes. However these ideas did not seem to start drawing together until the period in which Galileo lived (1564-1642).

The part that astrology played in the development of astronomy is rather illuminating, as part of their programme the astrologers wanted to known exactly where heavenly bodies would be at some point in time in the past or future therefore they expended considerable, skilled effort in measuring the locations of these bodies and building models from these measurements. This was the work that lead Copernicus to propose a heliocentric solar system, and would have fed into Newton’s work on gravity, and all done for completely ridiculous reasons. This also highlights some of the oddities in the thinking of the early pioneers of the modern period, for example William Gilbert, who did excellent work on magnetism did it in a distinctly odd framework – he believed the magnet was the soul of a planet, similarly William Harvey’s work on the circulation of blood and Isaac Newton’s obsessive alchemy and bible study.

During the Middle Ages there were various technological developments: the mechanical clock (Norwich, 1273), spectacles (Venice, 1300), modern printing (by Gutenberg around 1439). Paper making had been brought to Europe at some time before 1276 when the first paper mill is recorded in central Italy. Gunpowder was first mentioned in Europe by Roger Bacon (1267), having been invented in China in around the 9th century. These inventions largely arose outside of the university system.

The book ends with the death of Galileo in 1642, who had been subjected to a trial for heresy following which he was held under house arrest for the remainder of his life. The book makes clear, that in common with Newton, Galileo was “standing on the shoulders of giants” drawing heavily on work in the Middle Ages – although synthesising into a coherent whole, making his own additions and also covering a large range of topics over his lifetime.

Finally there is a timeline, a cast of characters and a nice, manageable set of further readings.

I feel ambivalent about this book, the historical aspects of it I found very interesting, the proselytising less so. It seems evident that there was progress in proto-science during the Middle Ages, and also in technology. Hannam claims that the Catholic Church facilitated this progress; the evidence he presents is mixed – they supported scholarship and the founding of universities but simultaneously ran a system of Inquisition to detect heresy which made free academic enquiry difficult.

Image: Frontspiece of Bible Moralisee, God the Geometer.