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We are the British Library Science Team; we provide access to world-leading scientific information resources, manage UK DataCite and run science events and exhibitions. This blog highlights a variety of the activities we are involved with. Follow us on Twitter: @ScienceBL. Read more

20 April 2016

The Thinking Machine: W Ross Ashby and the Homeostat

The British Library holds the personal archive of W. Ross Ashby - psychiatrist and expert in cybernetics (the study of the control of systems using technology). In this guest post Hallvard Haug, postdoctoral fellow at Birkbeck, University of London, examines the figure of W. Ross Ashby and his key invention the homeostat - a machine capable of adapting itself to the environment. A shorter article on W. Ross Ashby is featured on the British Library Untold Lives blog.

Ross Ashby (1903-1972) was a central figure of the post-war cybernetics movement in the UK, especially due to the popularity of his books Design for a Brain (1952) and  An Introduction to Cybernetics (1956). Ashby kept a thorough record of his thoughts throughout his adult life, and a collection of his papers has been donated to the British Library by his family.

Photograph of W Ross Ashby taken in his office 1963, Biological Computing Laboratory, University of Illinois. Copyright the Estate of W. Ross Ashby.

The centrepiece of the collection is Ashby’s notebooks which he kept from 1928 up until the year of his death. Among students of cybernetics these are legendary, and for good reason. Over the course of nearly 50 years, Ashby took meticulous stock of his thoughts on the material nature of the brain, and the notebooks show the workings of a highly systematic and deeply creative mind. Written in a precise hand, the journals brim with insights, speculations, calculations, graphs, drawings, newspaper clippings and circuit diagrams. Ashby also kept a meticulous topical record complete with content pages, cross referencing, summaries of entries, as well as two different sets of indexes — also included in the collection (Add MS 89153/27-30). Eventually, the notebooks ran to 7189 pages and spanned a total of 25 volumes.

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Journals 18-25 with handwritten labels including page numbers (Add MS 89153/18-25). Copyright the Estate of W. Ross Ashby.

At first, the notebooks were a pastime; eventually, however, the ideas Ashby explored became original enough to be publishable and in time these notes became the focus of his working life as his cybernetics work. The most famous of his innovations was the homeostat, a machine which demonstrated and embodied his theory of learning and adaptation in a mechanical apparatus which, entirely on its own, regains stability when perturbed. The development of the homeostat is documented thoroughly in the notebooks, from its first entry on 19 November 1946:

"I have been trying to develope [sic] further principles for my machine to illustrate stability, + to develope ultrastability" (Add MS 89153/9).

In the coming years, it was the centrepiece for his cybernetic activities.

The homeostat — a bulky and somewhat baroque machine built from military surplus parts — had a single purpose: to regain stability in response to perturbations in its environment. It is hard to convey precisely how the homeostat worked: set up as four identical units connected to each other via electrical inputs and outputs, each unit was topped with electrically conducing vanes dipped in water troughs. Like oscillographs, the vanes moved back and forth in the trough, reacting to the electrical input from their environment — the output from other blocks in the setup — and each block had an electrical output determined by the position of the vane in the trough. If the vane was directly in the middle of the trough, the electrical output was zero; if, however, it was positioned any other place in the trough, it provided electrical output to the other blocks, affecting the positions of the vanes it was connected to. Thus, when the machine was set in action by pushing a vane out of position, the vanes on all four units would react by moving back and forth, in reaction to their respective environments.

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Image of Ashby’s hand drawn diagram for the final version of the Homeostat from page 2432, Journal 11. (Add MS 89153/11). Copyright the Estate of W. Ross Ashby.

What made the homeostat so interesting, however, was its ability to return to equilibrium once a vane had been upset. Each of the units was constructed to also produce electric feedback to their respective vanes, depending on the conductivity of the vane. This feedback was determined according to a random table, and the machine would cycle through the table as long as the electrical output was not zero. Eventually, however, the vanes, cycling through random states, would come to a halt as each block found the appropriate feedback configuration. For Ashby, the return to equilibrium that the homeostat demonstrated was equivalent to the brain’s — whether human or animal — capacity for learning. The return to equilibrium demonstrated by the homeostat also showed how what only seems purposeful can come about by randomness, and Ashby believed this principle of feedback mechanisms spontaneously restoring equilibrium was a governing principle in nature. Indeed, in 1945 he noted that he had decided to follow in Darwin’s footsteps: like with the homeostat’s return to equilibrium, he viewed a species’ evolutionary adaptation to its environment as a return to equilibrium, and is only apparently purposeful. This tendency towards what Ashby called ‘ultrastability’ was referred to by Norbert Wiener as no less than ‘one of the great philosophical contributions of the present day.’ Eventually, Ashby was invited to present it at the ninth Macy conference for cybernetics in 1952.

Image of the Homeostat taken from Ashby’s lecture slides. (Add MS 89152/40). Copyright the Estate of W. Ross Ashby.

The influence cybernetics exerted on both the sciences and humanities in the 1950s and ’60s was considerable: its central insights touched upon, transformed and occasionally dominated disciplines ranging from computer science, artificial intelligence and genetics through psychology and sociology, and also influenced intellectual movements such as structuralism. Its universal character gained it great popular appeal, but also meant cybernetics never had a comfortable institutional or disciplinary home, with only a few university departments dedicated to it. Despite its popular appeal, Ashby has remained something of an obscure figure. The autobiographical notebook ‘Passing through nature…’ gives a rare insight into his private thoughts, and suggests that it was at least partly due to Ashby’s reticence towards being in the public eye:

"My fear is now that that [sic] I may become conspicuous for a book of mine is in the press. For this sort of success I have no liking. My ambitions are vaguer.

   I am something of an artist, not with pencil or paint, for I have no skill there, but with a deep appreciation of the perfect. […] I have an ambition some day to produce something faultless." (Add MS 89153/33)

Against his inclinations, Ashby set out to spark public interest in his ideas in the 1940s, and for a brief period the homeostat was the topic both of popular magazines and radio shows, promoted as an ‘artificial brain.’ Ashby kept a record of his success, pasting newspaper clippings in the notebooks. The journals are a treasure trove for insight into the trajectory of ideas: from the premature attempts at precisely stating a problem, to the mature implementation, years later, of a successful theory and its subsequent dissemination.

Hallvard Haug is a Wellcome ISSF postdoctoral fellow at the Centre for Medical Humanities at Birkbeck, University of London. His interest in W. Ross Ashby stems from his PhD research on the history of human enhancement technologies, which included a section on cybernetics.

Further reading:

The British Library acquired the W. Ross Ashby archive in 2003. It consists of notebooks, correspondence, notes, index cards, slides and offprints and is available to researchers through the British Library Explore Archives and Manuscripts catalogue at Add MS 89153. The estate of W. Ross Ashby also maintains a website The W. Ross Ashby Digital Archive which contains digitised copies of much of this material as well as a biography and photographs. It can be found at

Andrew Pickering, The Cybernetic Brain: Sketches for Another Future (Chicago: 2010).

Norbert Wiener, The Human Use of Human Beings, 2nd ed. (London: 1989).

23 March 2016

Science and Art in the rehearsal room

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Ziggy Jacobs is Lighting Designer for Calculating Kindness, which is presented by Undercurrent and Camden People’s Theatre in partnership with the British Library. The production was researched using the papers of George R Price and W.D. Hamilton held at the British Library. George Price (1922-1975) was an evolutionary biologist who formulated the Price equation which is widely acknowledged as the mathematical explanation for the evolution of altruism.

Tell us a little about your usual creative process, and how this differs when working on a Science & Art project?

I specialize in the intersection between science, technology, art, maths, and performance – so a show like this is a gift, and it’s why I was contacted by Laura Farnworth (Director). 2
I don’t think of “art” and “science” as separate things at all, so I find exploratory processes in all fields immensely creative. There’s a flip side to that coin however, in that I find some performance and scientific work can be equally dry and un-creative, when they are not exploratory or experimental. I think we have become unfortunately stuck in a cycle of creating theatre lighting in a very limited way, working from what our existing tools can achieve. This breeds a kind of expected repertoire of pretty techniques which are applied over and over again, a lexicon of colour temperatures and shapes which are signifiers for a regular and dedicated audience of mostly other performance makers.

7I wholeheartedly believe in beginning from scratch – asking what we want to achieve, what story are we telling, and thinking sky-high about what visual elements can support that, discussing them in initial meetings and devising sessions. During rehearsals, those ideas can be pared back to the achievable, and engineered from the ground up. It may require building an app, creating a new source of light, learning from the technology of completely disparate or unexpected industries, or engineering a brand new concept – and sometimes it needs a 2kW Fresnel and a good old fashioned profile fixture. The point is that I never know what the show needs, simple, complex, or unheard of, until I work within it, and I like it that way. I like to learn new skills, hone old ones, and start from total scratch each time – I think it’s the only way to inject innovation into performance tech. Lucy Sierra is an incredible designer to work with for this kind of process. We work in a very similar way – she doesn’t start outside or inside a box. There just isn’t a box to consider. It means that she comes up with these incredible visual images that I can bounce technological ideas off of, and every time we work together I am very proud of an original concept and execution that we create. 6

How have you related the Price equation to your design?

I went through a number of ideas about how to relate the equation – from creating a “population” of sources that could demonstrate “fitness” and attrition in a live way every night, to a brain-world that reflected neurological activity through the light. In the end, we have decided to create a corner of George’s mind, where this story lives, and the lighting is related to the things that occupy this mind. The equation, and George’s mind, are reflected in an organized, angular way, but also have a natural and dynamic quality to their movement, a sort of spontaneous variable. The most important sources attached to the equation exist as they are, they do not make a judgement, or attempt to lead perception in a single direction – just like the equation doesn’t. They are neutral factors, their spread and activity is inevitable, fractal.

3To an extent the individual sources are a population, and each one has had to survive the selection process; you will see clearly that the successful attributes and the “fittest” type of sources certainly demonstrate a covariance with their frequency in the population of lighting objects. If you view the entire lighting of the Camden People’s Theatre as a population of controllable sources, we have increased the figure dramatically – and the frequency of one type of source is drastically higher by the same amount. This can be seen as very much like genetic frequency; when the frequency of one gene (this type of source) increases in a population, the fitness of the population is covariant (the fitness of lighting objects in the theatre). Obviously they are not able to reproduce (although that could be an amazingly cost-effective idea!), but the concept is sort of beautifully similar! 

Undercurrent’s Calculating Kindness opens at Camden People’s Theatre on 29 March until 16 April. All images used with kind permission of Undercurrent UK.

15 March 2016

Tunny and Colossus: Donald Michie and Bletchley Park

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In honour of British Science Week Jonathan Pledge explores the work of Donald Michie, a code-breaker at Bletchley Park from 1942 to 1945. The Donald Michie papers are held at the British Library.

Donald Michie (1923-2007) was a scientist who made key contributions in the fields of cryptography, mammalian genetics and artificial intelligence (AI).

Copy of a photograph of Donald Michie taken while he was at Bletchley Park (Add MS 89072/1/5). Copyright the estate of Donald Michie/Crown Copyright.

In 1942, Michie began working at Bletchley Park in Buckinghamshire as a code-breaker under Max H. A. Newman. His role was to decrypt the German Lorenz teleprinter cypher - codenamed ‘Tunny’.

The Tunny machine was attached to a teleprinter and encoded messages via a system of two sets of five rotating wheels, named ‘psi’ and ‘chi’, by the code-breakers. The starting position of the wheels, known as a wheel pattern, was decided by a predetermined code before the operator entered the message. The encryption worked by generating an additional letter, derived from the addition of each letter generated by the psi and chi wheels to each letter of the unencrypted message entered by the operator. The addition worked by using a simple rule represented here as dots and crosses:

• + • = •

x + x = •

• + x = x

x + • = x

Therefore using these rules, M in the teleprinter alphabet, represented as:  • • x x x, added to N: • • x x •, gives • • • • x, the letter T.

Detail of the Lorenz machine showing the encoding wheels. Creative Commons Licence.

In order for messages to be decrypted it was initially necessary to know the position of the encoding wheels before the message was sent. These were initially established by the use of ‘depths’. A depth occurred when the Tunny operator mistakenly repeated the same message with subtle textual differences without first resetting the encoding wheels.

A depth was first intercepted on 30 August 1941 and the encoding text was deciphered by John Tiltman. From this the working details of Tunny were established by the mathematician William Tutte without his ever having seen the machine itself; an astonishing feat. Using Tutte’s deduction the mathematician Alan Turing came up with a system for devising the wheel patterns; known as ‘Turingery’.

Turing, known today for his role in breaking the German navy’s ‘Enigma ‘code, was at the time best known for his 1936 paper ‘On Computable Numbers’ in which he had theorised about a ‘Universal Turing Machine’ which today we would recognise as a computer. Turing’s ideas on ‘intelligent machines’, along with his friendship, were to have a lasting effect on Michie and his future career in AI and robotics. 

Between July and October 1942, all German Tunny messages were decrypted by hand. However changes to the way the cypher was generated meant that finding the wheel setting by hand was no longer feasible. It was again William Tutte who came up with a statistical method for finding the wheels settings and it was the mathematician Max Newman who suggested using a machine for processing the data.

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Colossus computer [c 1944]. By the end of the War there were ten such machines at Bletchley. Crown Copyright.

Initially an electronic counter dubbed ‘Heath Robinson’ was used for data processing. However it was not until the engineer Thomas Flowers, designed and built Colossus, the world’s first large scale electronic computer, that wheel patterns and therefore the messages could be decrypted at speed. Michie too, along with Jack Good, played a part, discovering a way of using Colossus to dramatically reduce the processing time for ciphered texts.

The decrypting of Tunny messages was critical in providing the Allies with information on high level German military planning in particular for the Battle of Kursk in 1943 and surrounding preparations for the D-Day invasion of 1944

One of the great ironies is that much of this pioneering and critical work remained a state secret until 1996. It was only through Donald Michie’s tireless campaigning that the General Report on Tunny, written in 1945 by Michie, Jack Good and Geoffrey Timmins, was finally declassified by the British Government; providing proof of the code-breakers collective achievements during the War. 

Pages from Donald Michie’s copy of the General Report on Tunny. (Add MS 89072/1/6). Crown Copyright.

 Donald Michie at the British Library

The Donald Michie Papers at the British Library comprises of three separate tranches of material gifted to the library in 2004 and 2007. They consist of correspondence, notes, notebooks, offprints and photographs and are available to researchers through the British Library’s Explore Archives and Manuscripts catalogue at Add MS 88958, Add MS 88975 and Add MS 89072.


Jonathan Pledge: Curator of Contemporary Archives and Manuscripts, Public and Political Life

Read more about ciphers in the British Library's collections on Untold Lives