Tag Archive: history of science

Sep 22 2020

Book review: The clock and the camshaft by John Farrell

camshaftThe clock and the camshaft by John Farrell is the story of technology through the Middle Ages which went on to support the Renaissance and the Scientific Revolution.

The book is structured by invention, and although some of the inventions are technologies as we would generally understand them there are also chapters on universities and monasteries, and languages. Each chapter looks at the ancient antecedents of a technology, where there is one, before looking at its place in the Middle Ages and how it played on to the Renaissance that followed. The antecedents are typically in the Roman Empire, China and the Middle East. The overall structure of the book is reminiscent of the technology “trees” one finds in a certain sort of computer game (Civilisation/Age of Empires).

There was a huge drop in population after the end of the Roman Empire in Europe in the 5th century CE until the 9th or 10th century. People no longer lived in towns or cities, and the art of building with stone appears to have been lost across much of Europe.

Food is a core concern at anytime and there were a couple of technological developments during the Middle Ages which helped here. The plough, used in the Mediterranean, was developed to better suit heavy Northern European soils. Horses were adopted to pull ploughs through the development of horse shoes and suitable harnesses.

In the Middle East water wheels were used in irrigation, from several centuries BCE. In Northern Europe irrigation was not quite such a concern but water wheels for power, in the first instance for milling wheat were important. This is not a simple technological development, for most individuals working the land it is convenient to hand mill wheat for your own consumption – a water powered mill is not worth the effort in maintenance or in initial capital outlay. This is where feudalism and monasteries get involved, feudal barons and monasteries can build and maintain a mill economically and they have subjects whose grain can be milled, for a price. Feudal masters obliged their subjects to use their mills, and pay a tariff to do so and under threat of punishment if they were found to be milling their own grain.

Once you have something that goes round and round, driven by a water or wind mill, then the next step is something that goes forwards and backwards. Or, more prosaically, converting rotation motion to linear motion. This might be to power a saw, or more often, to hammer things. Hammering things is important in the production of cloth (fulling), paper (pulping), and metal (crushing ore).Who would have thought hammering things was so important?

Paper is another key technology, the earliest writing is found in clay which was then superseded by papyrus – produced almost exclusively in Egypt. For rough notes codexes were used – parallel thin pieces of wood tied together. In Europe, after the fall of the Roman Empire, parchment made from the skins of goats or calves was used but this required a lot of dead animals. Meanwhile in China paper made from rags was being developed. This innovation was developed in Europe too, this arrival was key for new businesses. Now tradespeople could write things down relatively freely, critical for banking, and important in other businesses.

The challenge with clocks is to allow an power source to release its energy at a steady rate, this is done using an “escapement” mechanism. The first mechanical clocks were recorded in Europe towards the end of the 13th century.

Having forgotten how to build with stone at the end of the Roman Empire the cathedrals of the Middle Ages, built mostly in the 12th and 13th centuries were a sign that the skill of building with stone had been rediscovered. They were an evolution of Roman designs for grand buildings which allowed for much greater light through the insertion of windows. They followed the stone built castles of the Norman period around 1000 CE. Cathedrals are a rather more complex building than a castle but castles provided a good training ground.

Religion provided the impetuous for collecting manuscripts from the Arab world, during the 12th and 13th centuries with a view to improving their astronomic determinations of the date of Easter. Along the way they collected other manuscripts, returning to Spain and Italy to translate them.

Eye lenses were introduced in the first half of the 12th century, and appeared to evolve from glass used to display relics. There were antecedents of lenses found in ancient Egypt even back to the Bronze Age. The Venetians were early specialists in glass making, founding a guild in 1320. There was also expertise north of the Alps in Nurembourg but the quality of ground lenses dropped from 1500 with the first telescope makers towards the end of the century making their own lenses rather than buying them.

Monasteries, and monks, played an important role in carry knowledge across the Middle Ages after the fall of the Roman Empire. They were also important players in the material world, taking the part of a sort of feudal lord in some instances. Universities were in some senses a spin off from the collision between the Church and the Secular state, they arose originally as a place to study law – a topic which came to the fore in disputes between the Church and secular states over which had legal authority. Universities and monasteries are both examples of legal entities which were not people, an important innovation in law.

The book finishes with a chapter on lodestones which lead to the development of compasses for navigation, astrolabes and boats. Astrolabes were designed for astronomical measurement but also served as timekeepers, their design fed into the layout of the clock face. Boats were another technology which evolved as it moved north, the key innovation was switching to a skeleton-based design where the keel and ribs were laid down first, and then planks attached to them.

I liked this little book, much of what I’ve read in the history of science covers a later period – from the 17th century onward – The Clock and the Camshaft provides useful background, and is also very readable.

Jun 07 2020

Book review: Science City by Alexandra Rose and Jane Desborough

science_cityOn Twitter I hang out with a load of historians of science, and this has lead me to Science City: Craft, Commerce and Curiosity in London 1550-1800 by Alexandra Rose and Jane Desborough. This is an edited volume which accompanies the new Linbury Gallery at the Science Museum, combining objects from the Science Museum, King George III collection and the Royal Society. This book touches on many of the books I’ve read previously on the Board of Longitude, the transit of Venus, surveying and map making.

The main part of the book is four roughly chronological chapters covering the development of an instrument making industry in London, the Royal Society, public displays of science, and global expeditions. At the beginning of the period covered by the book, 1550, London was not a particularly notable city – it was a quarter the size of Paris and only twice the size of Norwich – England’s second city at the time. It had no universities, in fact it wasn’t to have a university until 1826.

The instrument trade in London started with a need to fulfil the requirement for “mathematical instruments” for surveying, gunnery and architecture. It was boosted by immigrants from the Low Countries fleeing persecution. In 1571 5% of the London population were “strangers” – born outside of England. These immigrants were not unwelcome, foreign manufactured goods were often seen as better quality which caused some resentment in the Guilds. Skills were developed and maintained by apprenticeships. These were typically found by personal contacts in the 16th century, there was no advertising of positions. Science City traces some apprenticeship “lineages”. In the early days there was no specific Guild for instrument making.

The second chapter brings in the Royal Society founded in 1666. As well as the instrumental needs of Robert Hooke, its Curator of Experiments, it stimulated a wider trade in instruments. The members of the Royal Society were keen to replicate experiments, or do their own experiments to share with the Society (or at least keen enough to spend money on instruments). Variants of the air pump demonstrations Hooke did were still being done 40 years later. The Royal Society put London at the centre of a network of scientific correspondents, and to some degree defined the way to be a scientist that maintains to this day.

In the ensuing years public science became a popular entertainment. Popularisers of science needed instruments to ply their trade. By this point in the first half of the 18th century there are 300 instrument makers in London, their business is divided into mathematical instruments (theodolites, sextants and the like), optical instruments (microscopes and telescopes) and philosophical instruments (those used to demonstrate physical principles). Its interesting to see the birth of branding at this point, makers were known by their shops signs and for clarity they would typically use a consistent image across there pamphlets and shopfront (rather than simply words). Examples include Benjamin Martin’s “spectacle” logo, and Edward Culpeper’s crossed daggers.

The final chapter covers the second half of the 18th century, this is at a time where the Ordnance Survey is founded alongside triangulation surveys with France. The chapter speaks to the global reach of London in trade and in science. This is the time of the Board of Longitude which was founded, making its major awards to John Harrison for his chronometer in the second half of the 18th century. The expeditions to view the transit of Venus in 1769 were also significant – the Royal Society petitioned the King to fund an expedition to Tahiti, this was accompanied by other expeditions which led to a requirement for moderately standardised instrumentation to make the measurements. London was able to supply this demand.

Science City finishes with interviews with an instrument maker (Joanna Migdal), the President of the Royal Society and the Lord Mayor of London (also a trustee of the Science Museum). The first of these I found really interesting I wish there were photos of the sundials the interviewee made, you can find some here on their website. Migdal’s work, individual, handcrafted items, is probably in the character of the instrument making of this book but differs from the typical instrument ecosystems these days.

The book is rather smaller than I expected but it is beautifully illustrated, more a bedside table than a coffee table book. I enjoy these catalogues of museum exhibitions more than the exhibitions themselves. In the gallery you are pushed for time and space, reading the descriptions can be difficult cross-referencing to other things you have read is impractical. A book makes it a more comfortable process but just lacks the immediacy of seeing the objects “in-person”.

May 08 2020

Book review: The Pope of Physics by Gino Segrè and Bettina Hoerlin

fermiThe Pope of Physics by Gino Segrè and Bettina Hoerlin is the biography of Enrico Fermi. I haven’t read any scientific biography for a while and this book on Enrico Fermi was on my list. He is perhaps best known for leading the team that constructed the first artificial nuclear reactor as part of the Manhattan Project. As a lapsed chemical physicist I also know him for Fermi surfaces, Fermi-Dirac statistics, and the Fermi method. Looking on Wikipedia there is a whole page of physics related items named for him.

Fermi was born at the beginning of the 20th century, his parents were born before Italy was unified in 1870 when illiteracy was not uncommon and people typically stayed close to home since travel quickly involved crossing borders.

Fermi was identified as something of a prodigy whom a friend of his father, Adolfo Amidei, took under his wing and smoothed his path to Pisa Scuola Normale Superior. As I sit here in in a mild lockdown I was bemused to note that the entrance exams Fermi took were delayed by the 1918 Spanish Flu pandemic. At Pisa Fermi learned largely under his own steam, at the time physics was not an important subject – the Pisa Scuola had five professors in physics and only one in physics. Fermi graduated at the top of his class.

After Pisa Fermi fell into the path of Orso Mario Corbino, a physicist, politician and talented organiser who set about helping Fermi to build a career in physics. At the time a new quantum physics was growing, led primarily by young men such as Pauli, Dirac, Heisenberg and Schrödinger who was a little older. Fermi met them on a scholarship to Göttingen in Germany. He later went to Leiden on a scholarship where he met Ehrenfest, and Einstein who was very taken with him. This was preparation for building a new physics capability in Italy.

The fruits of this preparation were a period in the mid-1930s which saw Fermi and his research group at Rome University invent a theory of nuclear decay which revealed the weak nuclear force and postulated the existence of the neutrino (this theoretical work was Fermi’s alone). The wider research group studied the transmutation of elements by slow neutron bombardment. This work was to win Fermi the 1938 Nobel Prize for Physics.

This research led on directly to the discovery of nuclear fission and the chain reaction which became highly relevant as Fermi fled Italy to the US with his wife on the eve of the Second World War. Many of Fermi’s friends, including his wife Laura, were Jewish. Fermi steered clear of politics to a large degree, he benefitted from the patronage of Mussolini but was no fascist enthusiast. The Italian uses of chemical weapons in Ethopia and, ultimately, the racial laws of the late 1930s which expelled Jews from their positions drove him from the country. He had visited the US a number of times in the early 1930s and had little trouble finding a position at Columbia University.

The route to the atomic bomb was not quick and smooth in the early years of the war, a number of physicists had noted the possibility of the fission bomb and attempted to warn politicians of its potential. This all changed when the Americans joined the war, following the Japanese attack on Pearl Harbour.

Building an atomic bomb presented a number of scientific challenges which Fermi was well-placed to address, primary amongst these was building “Critical Pile 1” the first system to undergo a self-sustaining nuclear chain reaction. It was constructed, slightly surreptitiously, in a squash court at Chicago University. It was built there as a result of a dispute with the contractor who was due to build it a little outside Chicago, at Argonne.

The “critical pile” demonstrated two things: firstly that chain reactions existed, and secondly it provided a route to producing the nuclear isotopes required to produce a bomb. It still left the question of how to purify the isotopes, and the question of how to produce a critical mass fast enough to cause a worthwhile explosion.

Fermi would go on to help in the Manhattan Project at Hanford and then Los Alamos where he held a position combining both universal scientific consultancy and administration, or at least organisation.

It is difficult to talk about Fermi’s strengths as a physicist – he had so many – he is almost unique in being both a top flight experimentalist, and theoretician. This is the great divide in physics, and people who are talented in both fields are rare. He was also clearly an excellent teacher, as well as undergraduate teaching and writing a high school physics book he supervised 7 students who would go on to earn Nobel Prizes in physics. Alongside this he was clearly personable.

Fermi died in November 1954 a little after his 53rd birthday, leaving in his wake a large number of prizes, buildings and discoveries as a memorial.

I found The Pope of Physics highly readable, the chapters are quite short but focused.

Mar 05 2020

Book Review: The Egg & Sperm Race by Matthew Cobb

egg_and_spermI follow quite a few writers on Twitter, and this often leads me to read their books. The Egg & Sperm Race by Matthew Cobb is one such book. It traces the transition in thinking on the reproduction of animals, including humans, which occurred during the second half of the 17th century.

Prior to this we had some pretty odd ideas as to how animals reproduced, much of it carried over from the Ancient Greeks. Ovid and Virgil both claimed that you could make bees by burying a bull with its horns protruding from the ground, waiting and then cutting off the horns to release the bees! This confusion is not surprising, the time between mating and the appearance of young is quite long, and the early stages of the process are hidden by being very small, and deep inside animals.

A random “fact” I cannot help but repeat is that Avicena wrote that “a scorpion will fall dead if confronted with a crab which a piece of sweet basil basil has been tied”. I wonder sometimes with quotes such as these whether they are a result of mistranslation, or a bored scribe. The point really is such ideas were not discounted out of hand at the time. The Egg & Sperm Race starts with a description of da Vinci’s copulating couple which is beautiful but wrong – da Vinci connects the testicles to the brain – these structures do not exist.

The heart of the action in The Egg and Sperm Race is in the Netherlands, in England the Royal Society showed relatively little interest in generation aside from some experiments on the spontaneous generation of cheese mites. The Chinese and Arab scholars who had worked in various fields showed little interest in generation.

The central characters are Jan Swammerdam, Niels Stensen (known as Steno) and Reinier de Graaf, who met in Leiden at the university in the early 1660s when they were in their early twenties. Swammerdam and Steno were a little older than de Graaf and were close friends. Soon after meeting in Leiden they visited Paris where they continued to build contacts in the scientific community.

In understanding generation a first step was to realise that all animals came from other animals of the same species, and that this meant mating between two animals of the same species. Steno went to Italy and worked with Francesco Redi’s whose experiments were key to this, he checked exhaustively that insects did not arise from the putrefaction of material. Swammerdam was also interested in insects, classifying four different types of invertebrate development and showing that in moths traces of the adult form are found in the caterpillar. At the time it was not clear that the larval stage and the adult were the same species.

A second step was to realise that all animals came from eggs of some sort, William Harvey –  of blood circulation fame – did experiments in this area but although he stated this conclusion but it was not well-supported by his experiments. In the period at the beginning of this book, the role of the ovary was not understand. Steno carried out dissections on fish both those that laid eggs, and those that gave birth to live young from this he concluded that the ovaries were the source of eggs and asserted that this was the case for humans as well. This idea rapidly gained acceptance.

The discovery of the human egg, and its origins in the ovary, was the subject of a dispute between de Graaf and Swammerdam on priority. The Royal Society decided in favour of van Horne with whom Swammerdam had worked on the dissection and illustration of female reproductive anatomy. To modern eyes the written record of the dispute, in letters, and publications is surprisingly personal. De Graaf died at the age of 32 just prior to the Royal Society decision. It was a difficult time in the Netherlands with the country at war with England and France with France troops invading parts of the country.

Leeuwenhook cast a spanner into the works with his microscopical studies, he observed spermatozoa but not the female egg and as a result became a “spermist”, believing that life came from the sperm in contrast to the “ovists” who believed life came from the egg. We now know that they are both right. The human egg was not observed until 1826 by von Baer. And I have to mention Spallazani’s experiments on frogs wearing taffeta shorts, demonstrating that male sperm was required to fertilise the female egg.

The final chapter covers events from the end of the 17th century or a little later to present day. Linneaus’s classification work, and Darwin’s theory of evolution follow on from some of the core realisations of this earlier period. Neither Linneaus’ work nor Darwin’s work make much sense if you don’t believe that animals (and plants) grow from eggs/seeds which came from the same species. It wasn’t until von Baer’s work in the early 19th century that the female egg was observed.

Dec 26 2019

Book review: Higher and Colder by Vanessa Heggie

higher_and_colderHigher and Colder by Vanessa Heggie is a history of extreme physiological research in the later nineteenth and twentieth century. It is on the academic end of the spectrum I read, it is not a tale of individual heroics, although I found it quite gripping.

The action takes place largely in extreme environments such as very high mountains, and the polar regions. There are some references to high temperature environments but these are an aside. One of the themes of the book is the tension between laboratory physiological experiments, such as the barometric chamber work of Bert in 1874, and experiments and experiences in the field. It turns out it is hard to draw useful conclusions on survival in extreme environments from laboratory studies. Much of this work was done to support exploratory expeditions, mountaineering, military applications and more recently athletic achievement. The question is never “Can a human operate at an altitude of over 8000 metres?”, or the like, it is “Can Everest be scaled by a human with or without supplementary oxygen?”. So factors other than the “bare” physiology are also important.

Some of the discussion towards the end o the book regarding death, and morbidity in expeditions to extreme environments brought to mind the long distance marine expeditions of the 18th century. Its not discussed in the book but it seems like these extreme physiology field programmes go beyond simple field research, they are often parts of heroic expeditions to the ends of the earth.

The book opens with a discussion of mountain sickness and whether its cause is purely down to low oxygen or whether other factors are important. One section is titled “Only rotters would use oxygen?” – the idea being that climbing Everest was retarded by a reluctance to use supplementary oxygen. In fact oxygen apparatus only really became practical for climbers in the 1950s, so the reluctance is more to do with technology than honour. The climbing problem is different from a military aircraft where weight is relatively unimportant. Fundamentally there is no short term acclimatisation to altitude. Himalayan populations show some long term adaptations but Andean populations are quite different in terms of evolution scale adaption – populations in the Himalayas have been there much longer. Mentioned towards the end of the book is the fact that humans foetuses spend their time in a low oxygen environment, so these physiological experiments have applications well beneath the mountains and the skies.

The selection of participants into the field, both as experiment and subject, was based on previous experience, gender, class and connections. This means they were almost entirely white and male, particularly those to Antarctica where the US military refused to transport women for a considerable spell. The extreme physiology community is quite close-knit and difficult for outsiders to penetrate, there is a degree of nostalgia and heritage to their discussions of themselves. Although women played a part in missions dating back into the earlier 20th century their presence is hidden, publication culture would typically not name those considered to be assistants. The first woman to overwinter in the British Antarctica base was in 1996.

Native people are similarly elided from discussion although they were parts of a number of experiments and many missions. An interesting vignette: the conventional ergometer which measures human power output was found not to be well-suited to Sherpas since it was based on a bicycle, utterly unfamiliar to a population living in the high Himalayas where bicycles are uncommon. Also the oxygen masks used by Western climbers need to be adapted to suit the differing face shapes of Sherpas. Heggie introduces the idea of thinking of native technology as part of bioprospecting. I was intrigued to learn that “igloo” originally meant something very specific, one of a class of structures from compacted snow, but it was corrupted to mean any building made of compacted snow. Pemmican is another technology drawn from the natives of Arctic lands. These technologies are usually adapted and there is a degree to which they are not adopted until they have been “scientifically proven” by Western scientists.

It turns out that participants in polar expeditions don’t experience much cold – they are two well equipped and often expending a lot of energy. Cold is different to altitude, altitude is relatively un-escapable whilst cold can be mitigated by technologies dating back centuries.

I was broadly familiar with some of the material in this book from reading about attempts on Everest and Antarctic and Arctic expeditions but this work is much more focussed on the experiments than the men. I am contaminated with the knowledge that Heggie has worked with Simon Schaffer and felt that Higher and Colder has something of the style of Leviathan and the Air pump particularly the language around objects and artefacts, and their movement being about communication.

I found this a gentle introduction to the practice of historiography, it is related to the tales of adventure and individual heroism around scaling Everest and reaching the South Pole but quite different in its approach.

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