Sep 03 2017

Book review: Chester AD400-1066 by David Mason

chester400-1066adI couldn’t resist more Chester history, so now I am reading Chester AD400-1066: From Roman Fortress to English Town by David Mason. I’ve just read Jane Laughton’s book on late medieval Chester covering the period 1275-1520 (review here), and read David Mason’s book on Roman Chester (review here) towards the end of last year. This book fills most of the gap between those two books, but not quite.

Evidence for the early part of the period is sparse, particularly in the earlier years between about 400AD and 600AD – it isn’t known as the “Dark Ages” for nothing. During this time, after the Roman withdrawal, no durable mass-produced items such as coins or pottery were being produced. Elsewhere, in nearby Wroxeter, archaeological evidence suggests that the early Britons built wattle-and-daub huts within substantial Roman buildings. In Chester there is little such evidence. The various Roman buildings in Chester would have decayed at different rates. The baths under the now Grosvenor Shopping Centre had metre thick walls and would have only fallen down slowly, whilst the barracks in the north east quarter of the city were less substantial. At the barracks there are black deposits, possibly pigeon droppings, deposited between Roman and later date-able layers. It would seem that for most of the period from 400AD to 900AD Chester was a Roman ruin with some desultory farming and living taking place within its walls.

A little after this earliest period to 600AD there are are some written records, such as the Anglo-Saxon Chronicles, and Bede’s History which were written some time – dozens, even hundreds of years – after the event. There are songs and poems from Wales, transmitted orally, which refer to the period.

Chester enters the historical record of the period with the Battle of Chester in AD616, for which there is archaeological evidence in the form of a mass burial at Heronbridge, just south of the city. Here 120 skeletons were found dating to the same period as documentary evidence for the battle and with wounds consistent with dying in battle.

St John’s church, founded in 689AD sits next to the old Roman amphitheatre from whose remains it was built, although there is some suggestion that Christians were martyred at the amphitheatre, so it wasn’t simply a case of being unwilling to carry heavy stones further than necessary!

In common with the Roman period, and the later period covered by Laughton’s book Chester holds a key strategic position between Wales and Ireland on the one hand and the rest of England, variously inhabited by Dane’s and Anglo-Saxons on the other. I found some of the discussion here confusing with what I would refer to as “Celts” from Wales, the West Country, Scotland and Ireland described as “British” and those from Mercia and Wessex as “English”.

The final third or so of the book is devoted to Chester as a burh one of the network of fortified towns set up by King Alfred – Chester was established in 907AD. It’s at this point that Chester appears to turn into a proper town, and a moderately important one at that. In the years after its establishment as a burh Chester had “moneyers” – effectively a mint, twice the size of London. This is reflected in the discovery of coins minted in Chester being found in Ireland and around the Irish Sea. The establishment of the burh mandated taxation and physical labour to build its defences and bridges – it’s likely in this period that the modern circuit of the walls was constructed. There is more archaeological evidence from this period and the start of some form of systematic written records, rather than the non-contemporaneous writing alluding to previous periods.

It is during the period after the establishment of the burh that King Edgar holds his coronation in the city, in 973AD. By the time of the Norman conquest and subsequent Domesday census Chester had 431 houses and a further 56 belonging to the Bishop (presumably of St. Werburgh’s church which was founded by in Edgar in 758AD). It also had a system of laws and taxation detailed in the Domesday book.

The book ends with Chester suffering a setback in the years after the Norman conquest as a result of its part in rebellion against the incoming King William.

Chester AD400-1066 is a fairly slender volume but more readable than Roman Chester. As a result of the sparsity of the archaeological and written records for the period it is wider in its scope than books set before and after this period.

Aug 28 2017

Book review: Life in a late medieval city by Jane Laughton

medieval_chesterI’m back to local history with my next review. A while back I read Roman Chester by David J.P. Mason. I have his book Chester 400AD –1066AD on my “to read” pile but instead I am jumping forward to Life in a late medieval city: Chester 1275-1520 by Jane Laughton.

The book starts with some definitions and background. How do we define a city? What was the hierarchy of settlements in Cheshire and indeed the rest of England and Wales? This information can be inferred from various charters, and the like.

The book is laid out thematically, so having covered definitions of towns it then goes on to provide an overview of the historical background to the period. This is generally revolves around what kings were doing (invading Wales, crushing rebellions) but also mentions the rise and fall of Chester with famine and the Black Death.

Chester was an important location in Roman times, acting as a forward base for the Roman invasion of northern England and a potential jumping off point for Ireland. So it was in the late medieval period. The start of the time span of the book coincides with the time Edward I’s invasion of Wales when Chester was used as a garrison for the invasion force.

The next chapters cover the topography of the city and the built environment. The central streets of Chester, Eastgate, Bridge Street, Northgate and Watergate play a key part here – as they do to this day. In the period covered by the book these streets provided the key administrative divisions of the city, when citizens interacted with the bureaucracy they were labelled with their name and home street.

I am intrigued by the Pentice, which was a lean-to structure built against St Peter’s church at the Cross in the centre of the city which served as the base for administration for many years (you can see a picture of the Pentice on this page) – it was finally demolished in the early years of the 19th cenutry. The “Rows” are a key feature of the built environment even now, as they were in the late medieval period. For those that haven’t visited Chester the Rows are an arrangement whereby walkways runs through the first storey of the shops on Eastgate, Bridge Street, Watergate and Northgate (to a limited extent). Towards the street from the Row there is a flat, slightly sloped “stall” which was used to lay out goods in the past, beyond which is open to the street at first storey. Opposite the stalls are shops, and beneath the “Rows” are undercrofts. You can see pictures of the rows here, they haven’t changed a great deal over the years.     

Laughton makes it clear that the book is based on the records of courts and taxation within the city. So we know, for example, that the tanners in the city worked outside the Eastgate because there are court records of them being charged with blocking the city ditch with their cess pits. We know of the types of trade taking place in the city through taxation, rental and customs records.

Sometimes the relationship with the underlying records feels a bit direct. We are introduced to messuage with no explanation, a messuage is a dwelling and its land. And also pavage, murage and even pontage – these are taxes raised for the purpose of building and maintaining roads, walls and bridges respectively. The portmote, crownmote and piepowder courts are similarly introduced with little ceremony. Portmote are essentially courts in port town, crownmote are courts which cover the most serious offences and piepowder courts cover justice surrounding traders coming in from outside the city. Similarly a range of now obscure occupations such as corviser, souter, barker are introduced with little explanation. On the plus side I have learnt a host of new words for which to find application!

The book goes on with chapters on the hierarchical society and urban government. There is some overlap here with men moving through positions in the government of Chester, more rapidly if they are nobility.

This history of Chester is quite distinct from my readings in the history of science, the period it covers lies before the main developments in Western science. Copernicus (1473-1543), Mercator (1512-1594) and Galileo (1564-1642) are the earliest I’ve read about, most of the history of science I’ve read is post English Civil War. Science does have an equivalent to the administrative records in this book but they are impersonal records of the locations of stars and planets, and the like. Reading Life it strikes me that Chester (and undoubtedly the rest of England) had quite complex systems of law, ownership, trade and so forth from a very early time – science is something of a latecomer.

It feels like a book a bit more for the specialist than the general reader but I found it pretty readable and enjoyed the link it gave me to the medieval inhabitants of the city I live in.

Aug 13 2017

Book review: The Comet Sweeper by Claire Brock

thecometsweeperA return to women in science in this post where I review The Comet Sweeper: Caroline Herschel’s Astronomical Ambition by Claire Brock, a biography of a woman who discovered comets and nebulae and published a catalogue of astronomical objects in the later years of the 18th century. For scientists the name “Herschel” will not be unknown. Caroline Herschel’s brother William discovered Uranus, and was paid as an astronomer by King George III. Her nephew, John was also well known as a scientist. However, relatively little has been written about Caroline.

The Comet Sweeper is based substantially on the autobiographical writing of Herschel. However, she was sufficiently well-known at the time to be referenced elsewhere, and indeed later in her life was bestowed with various honours and medals for her astronomical work.

Herschel was born in Hanover in 1750, her father Isaac was a musician and very much a self-taught man – something he passed on to Caroline. Anna, her mother, gets a less than sympathetic treatment from her daughter and consequently this book. For her early years Anna treated Caroline as a servant, and stopped her education as soon as it appeared it would help her leave the Herschel household in Hanover. She was finally given a means of escape when her brother, William, invited her to Bath to work in music with him in 1771. She had no previous training in music and put herself assiduously to learning what she needed to know. William Herschel was earning up to £400 per year from music lessons and the like when he invited his sister to join him. It seems that Caroline became a significant musician in her own right, at least until her brother dragged her into astronomy.

This is something of a theme through the book, Caroline Herschel is clearly very capable and when given the opportunity can excel in whatever she turns her hand to. But the choices she has are limited. In the first instance her mother controls what she can do, then her brother – switching her from music to astronomy with little regard for her own wishes.

In astronomy Herschel started by assisting her brother in the workshop – at the time, to get the best telescope, you built them from scratch yourself. She supported him in his observations but she also carried out observations on her own. The “sweeping” of the title is the systematic scanning of the night sky with a telescope to identify static features such as stars and nebulae but more specifically to find comets. To a degree the discovery of nebulae was incidental to the main task of finding comets, nebulae were easily confused with comets so recording their locations was an essential part of finding comets. The Herschel’s work followed, but only by a few years, the publication of Charles Messier’s first catalogue of diffuse celestial objects in 1774.

As well as discovering comets and nebulae Herschel was also responsible for publishing Catalogue of Nebulae and Clusters of Stars in 1798, which built on the earlier work of Flamsteed. Ultimately this became the New General Catalogue of stars. Amateur astronomers will know this work, Messier’s catalogue provides information on the 100 or so most prominent objects whose identifying numbers are prefixed with an M- beyond this are the NGC objects – from the New General Catalogue which is the descendant of Herschel and Flamsteed’s catalogue.

Herschel was honoured in her own lifetime with a gold medal from the Royal Astronomical Society, as well as honorary membership and medal from the King of Prussia, at the age of 96. She was the first woman to be published in Philosophical Transactions the journal of the Royal Society. These awards did come until quite late in her life although she was paid £50 per annum by King George III as an assistant to her brother. He was paid rather more, £200, but notably rather less than he earned as a musician.

I found the broader insight that The Comet Sweeper gave into the lives of Georgian women was interesting. Women did not have formal positions within the scientific community of the time but they contributed as wives, sisters, daughters. At the time there was little in the way of formal, paid, scientific community – it was very much a gentleman’s club but there was a place for women in it although not necessarily of equal status.

This was to change later in the 19th century when science became institutionalised, as a result women were excluded by, for example, not being able to receive degrees or even attend lectures at university. 

The Comet Sweeper is not a long book, it is readable and casts an interesting light on women in science in Georgian England and the specific contributions of Caroline Herschel.

Aug 01 2017

Book review: Inventing Temperature by Hasok Chang

inventing_temperatureMy next read is more academic in character, Inventing Temperature: Measurement and Scientific Progress by Hasok Chang. As an undergraduate chemical physics student, temperature was important to me. On the chemistry side of the equation, increasing the temperature of a reaction by 10 degrees doubles its rate. Statistical mechanics forms the core of chemical physics, and this is very much about temperature and equilibrium. In a laser, light is emitted when population inversion is achieved which some describe as negative temperature. It’s fair to say that measuring temperature is one of the core activities of any physical scientist, even if all you are trying to do is keep your experiment at a fixed temperature.

The book starts with a discussion of the fixed points used in thermometry. For the familiar Celsius temperature scale these are (crudely) the melting point of ice and the boiling point of water. The temperature difference between these two fixed points is divided into 100 equal divisions, and the scale can be extrapolated above and below these fixed points.

But this isn’t so easy, it isn’t necessarily a given that ice always melts and water always boils at the same temperature – superheating and supercooling are things that will dog you, particularly if you take great care with your experiments! In a theoretical sense we now know that melting and boiling happen at fixed temperatures under fixed conditions. Experimentally exactly how you set your water boiling and your ice melting can change the temperature at which they appear to melt or boil. In the early days of temperature measurement these questions were all consuming and took many years to resolve.

Another question is “what does it mean to measure temperature"?”. Chang proposes a Principle of respect in the development of measurement and also epistemic iteration. That is to say that the development of the measurement of temperature is guided – respects – our perception of temperature but is not dominated by it. Sometimes our perception of temperature is wrong, epistemic iteration allows us to correct that perception or at least make our measurement correct. If you’d like an example of an incorrect temperature perception try testing the same water having run your hand under hot and cold taps – we perceive a different temperature even when there is no difference.

The next step in the process of measuring temperature is trying to make a linear scale which does not depend on the precise nature of the thermometer you use. This is difficult to achieve without having a clear idea of what temperature is. Linked to this is the problem of what the best “working fluid” is for your thermometer – although we are familiar with mercury and alcohol thermometers, from a scientific point of view “air thermometers” are the best behaved. To a 20th century physicist this is unsurprising but in the late 18th and early 19th century this was not obvious. Furthermore, air was more difficult to work with.

After considering the problem of the linearity of the temperature scale Chang turns to temperatures far above and below the fixed points of the scale, below where mercury freezes and above where glass melts. The challenge at low temperatures was attaining low temperatures, the challenge at high temperatures was finding any sort of device that could survive and keep working at high temperatures. For a long time a pyrometer invented by Josiah Wedgewood was used which relied on measuring the shrinkage of clay pellets as a measure of temperature. Joining this temperature scale to one measured at lower temperatures with conventional thermometers was hard.

Finishing the specific sections on measuring temperature is a chapter on theoretical considerations, focusing on the work of Joule and Thomson. Who established an absolute temperature scale, and under what circumstances a gas could be used to measure such a scale.  Epistemic iteration plays a part here as the combatants need to find a concrete system to demonstrate an abstract principle, and show that their concrete system is close to being abstract!

The book ends with two chapters on more general matters in the history and philosophy of science. The first of these is on Chang’s view of how science progresses. The second is on what Chang calls “complementary science”, how the history and philosophy of science could lead to an increase in scientific knowledge. In my view scientific progress would likely be improved if students were taught better in the history of their subject.

I found this book fascinating, as far as I can recall I came across a much abbreviated form of some of this work during my A-levels when I wasn’t really able to appreciate the scale of the challenge in the now simple act of measuring temperature. Once at university measuring temperature was a given but I gained a more sophisticated understanding of what temperature meant – an understanding that was based on theories developed in the late 19th century.

Jun 29 2017

Book review: Numbers and the making of Us by Caleb Everett

numbersMy next read is Numbers and the Making of Us by Caleb Everett. It is a book about our innate numerical senses, and how we developed skills beyond them that are enabled by the language of numbers.

The book starts with an overview of numbers in writing systems. Highlighting that ways of recording numbers, in the form of tallies, appeared before full blown language. Tallies seem to be evident in prehistoric artefacts before being found in the Fertile Crescent where they were used to record quantities of grain and the like in early written languages. Later in the book Everett proposes that “static” agriculture drives the development of numerical language, citing as evidence the fact that the few remaining hunter-gatherer societies have fewer number-words than their agricultural counterparts. He suggests that as specialisation due to agricultural occurs, it becomes necessary to record amounts of food so that they can be bought and sold (or exchanged for other goods).  

I was interested to read that many human number systems are quinary, decimal or vigesimal, or put more simply based on 5, 10 and 20. This relates to the number of fingers and toes we have, our number words are linked to the numbers of our fingers and toes because they are used for counting. In some languages the link to fingers and toes is explicit, whilst in Western European languages it is not. Vigesimal vestiges remain – in English the number 20 has it’s own special word – score. And in French eighty is quatre vingt and ninety is quatre vingt dix. Later in the book, Everett suggests that our bipedalism helps with the development of counting – our fingers being relatively available (unlike toes) and also important because of our use of tools.

Numbers don’t just come into language in the form of numbers, they can be inferred in the plurals of nouns, or in the forms of verbs. In English we are used to the idea of adding an “s” at the end of a word to make a noun a plural. This is common across many languages. Plurals can also be formed with prefixes (at the start of the word), and even “Infixes”. For example in the Tuwali Ifugao language woman is babai but women is binabai. The plural is formed by adding –in- within the word. But not only this, number can be indicated in the conjugation of forms, and pronoun forms. English is a bit sparse in this regard, other languages have pronouns indicating two or three people as well as just the English divisions of one (I) and many (we).

It seems we have an innate, “exact” number sense for numbers up to three. Beyond three we have a innate, fuzzy number sense meaning we can tell when objects groups are more than or less than one another but where we cannot accurately subject the numbers of objects in a group. Beyond these two senses is a matter of learning.

The evidence for this comes from a number of places, the first of these are experiments with people from anumeric Amazonian tribes and Nicuraguan home signers, who are also anumeric. By anumeric, we mean that they do not have number words beyond three. These people are able to distinguish small numbers exactly but become increasingly inaccurate beyond 3.  

A second strand of evidence comes from the investigation of numeric ability in children, some as young as 48 hours old! Although older children can be questioned directly in spoken language regarding numbers, for younger children it is necessary to use indirect methods. In particular, researchers can track gaze, and watch the absence of sucking on a dummy. Children (and adults), turn their gaze to things they find interesting or unusual and will stop chewing/swallowing/sucking as well. An example experiment in this area is to hide an object behind a screen, and then pretend (or not) to add a second object of the same type, or remove the object. If the child shows excessive gaze, or reduced sucking then it is inferred they are surprised by what they see when the screen is dropped again. That’s to say if they see 2 objects when they expected 1, or vice versa. This surprise implies the ability to count.

Evidence for the exact and fuzzy number sense is also found in experiments on animals. Although some animals, following much training appear to be able to count exactly beyond 3 they are rare. Otherwise they show the same types of innate abilities that we have.

Language is the enabler for exact counting beyond three, clearly sometime in the past one or more humans has learned how to count. Embodying this ability into language enabled it to be transmitted to other, less gifted humans.   

I found this book really fascinating, interested, as I am in both words and numbers.

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