Author Archives: Michael Kay

Batteries, hairdryers, and an electrical therapy machine: using objects to teach the history of electricity

I am currently working with Harewood House, in north Leeds, on a collaborative project called ‘Harewood’s Electricity Story’, researching the history of the electrification of the house and producing new interpretation and engagement activities based on our findings.

As part of this project, on Thursday 11 August I ran a workshop at the university for students from IntoUniversity, a national charity which provides local learning centres where young people are inspired to achieve.  In particular they work with children from disadvantaged postcode districts who are statistically less likely to go to university or enter the professions than those in more advantaged areas, providing academic support, mentoring, and informal educational opportunities.

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Introducing the workshop.

After a short performance from our three actors about the history of electrification at Harewood in the 1930s, I used artefacts from our museum collections to talk about the history of electricity supply and use in the home.  These artefacts included two examples of early batteries – one wet cell one dry cell – with which I pointed out for example that country houses such as Harewood needed to supply their own electricity for a long time before they were connected to centralised power stations, and their electrical installations always included lots of large wet cell batteries. We also touched on the importance of measuring how much electricity you were using – so you knew what you were paying for!

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Showing the students a nineteenth-century voltmeter.

In contrast to fears about being hurt by electricity – which had been discussed in the performance – I also discussed how some people in the late nineteenth and early twentieth centuries used mild electrical currents as a form of therapy.  This last point I illustrated using a particularly interesting object from our collection: an electrical therapy machine designed for use at home, with two electrodes which the user would apply to parts of their body in order to administer a gentle electrical current.  This, it was argued, was efficacious against many ills, such as headaches, nervous disorders, and even deafness and baldness.  We believe ours dates from the late nineteenth-century, but devices such as these were certainly in use up until the 1920s and 30s.

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One of our electrical home therapy kits (we have two).

Whilst presenting these artefacts, I talked to students about best practice in museum object handling: the importance of gloves, of using both hands to pick things up and holding them over tables.  Next we gave the students the chance to handle some historic objects themselves.  Although our own collections were too fragile to allow this, we hired out handling objects from Artemis, the object loans service run by Leeds Museums and Galleries.  These domestic electrical appliances from the 19230s, 40s and 50s included hairdryers, a kettle, a wireless set, an iron, a toaster, a vacuum cleaner and a radiator, and students were very keen to put their gloves on and investigate.  As a hands-on activity this was very popular; the children were happy to have the opportunity to explore these objects themselves.  Knowing they were free to pick them up on their own was invaluable and a great experience.

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Gloves on! The students handle some old electrical objects from Artemis.

The energy levels in the room were fantastic throughout; the students certainly seemed to have a lot of fun, and we really enjoyed having them!

The funding for this project comes from The Culture Capital Exchange, a new joint initiative of Arts Council England and the Higher Education Funding Council for England which provides seed funding grants up to £5000 for collaborative research projects between academics, specifically Early Career Researchers, and creative small-medium enterprises or individuals, including artists, performers and heritage organisations.  You can read more about our project here, and for more information about this workshop see our blog post here.

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Seeing the light – Lord Kelvin’s mirror galvanometer

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One of our mirror galvanometers. In this instrument the mirror apparatus has been removed.

Amongst the many objects the museum has inherited from the old History of Education Museum collections are over thirty galvanometers, instruments used for detecting and measuring electrical current. Galvanometers work on the principle, first discovered by the Danish physicist Hans Christian Oersted in 1820, that electrical current flowing through a wire will deflect a magnetic needle. Amongst the galvanometers in our collections are several examples of the mirror galvanometer, a much more sensitive version of the original instrument which was first patented by William Thomson, later Lord Kelvin, in 1858.

The mirror galvanometer was developed in response to a pressing practical and commercial need; advances in submarine telegraphy demonstrated to engineers and investors alike that the scientific principles on which the technology was based were not properly understood. This became really important with the attempts to lay a telegraph cable across the bottom of the Atlantic Ocean to connect Great Britain and America in 1857 and 1858, the longest cable ever laid up until that time. The problem was that, over a long underwater cable, signals at the receiving end were very faint and difficult to detect. This was because the discrete electrical impulses became attenuated, stretched out, due to the capacitance, or electrical storage properties, of the long underwater cables. The end was result was that one signal would become stretched out and blurry, and multiple signals sent one after the other would run into one another and all that was detected at the receiving end would be a messy, unintelligible noise.

Two solutions were proposed to this problem. One was, effectively, to push more current through the wire (see here for more). However, the result of this was to burn out the already faulty 1858 cable, only three months and 732 messages after it had been laid (see Charles Bright, The Story of the Atlantic Cable, 1903). Thomson’s solution was instead to design a more sensitive receiving instrument. The mirror galvanometer comprised a small mirror with a magnet fixed to the back, suspended within a coil of wire so that it hung freely in the middle. When the current flowed through the wire, the magnet moved, thus twisting the mirror. A lamp was used to shine a light onto the mirror, and, as it moved, the light was reflected onto a scale set up opposite the galvanometer. This in effect created a weightless pointer. The movement of the light-spot on the scale indicated the presence, and the magnitude, of the current passing through the receiving instrument.

The author Arthur C. Clarke provided an elegant explanation for how this instrument detected such small currents: the initial electrical impulse, he wrote, in Voice Across the Sea, was like water behind the wall of a dam (1974, pg. 46-50). The edge was clearly defined by the vertical line of the wall. However, if the wall broke, the water would immediately begin to flatten out, and would form a wave, the crest of which would form a short distance behind the beginning of the flow of water. Clarke explained that this was similar to the attenuation of the electrical impulse; the first current to reach the receiving instrument from the original electrical impulse would be the equivalent of a trickle before the crest of the wave. The efficacy of Thomson’s mirror galvanometer arose from its ability to detect this initial trickle, without needing to wait for the crest of the electrical wave before registering a signal. Thus, it could rapidly provide separate readings for multiple, consecutive signals, one after another.

Mirror galvanometer, 1858, Science Museum
Here you can see the lamp and scale required to operate this 1858 mirror galvanometer (Science Museum, London).

The mirror galvanometer gave experimenters a tool for studying and quantifying electrical current which was so accurate that variations on it were used in laboratories for decades afterwards (see Graeme Gooday, The Morals of Measurement, 2004, pg. 137-48). It is thus a good example of an instrument which was devised for a commercial purpose but which then went on to benefit scientific research into electricity. The mirror galvanometer inspired such wonder amongst many of Thomson’s contemporaries that one, the physicist James Clerk Maxwell, was inspired in 1872 to write a short poem about it, parodying some of Tennyson’s verses: “The lamplight falls on blackened walls, and streams through narrow perforations. The long beam trails o’er pasteboard scales, with slow decaying oscillations. Flow, current, flow, set the quick light-spot flying. Flow, current, answer, light-spot, flashing, quivering, dying.” (Clarke pg. 51 or Gooday pg. 148)

Our mirror galvanometers date from the early 1900s, and would have been used in local Yorkshire schools to teach children about physics.

Museum training morning, 20/6/12

Last Wednesday, 20 June, Claire and Emily, museum director and curator respectively, ran an interesting and very informative training morning intended to bring us all up to the same level in areas such as collections management, artefact conservation, and the theory and thinking behind putting on an exhibition. The morning was well attended, and in addition to very useful training also provided an opportunity to meet and share ideas with other taskforce members.

Claire tells the taskforce about the physical agents of deterioration (and how to avoid them!)

Claire began by briefly updating us on the management situation of the museum and our progress on fully adhering to Spectrum guidelines – the international standard expected of all good museum collections. She also reiterated the museum vision, which remains to preserve and care for objects pertaining to the scientific, technological and medical heritage of Leeds and the surrounding area; to provide access to these to university students and staff and the general public through exhibits and displays; and to train and provide practical experience for students interested in HPS and museum studies. Next we looked at the practicalities of collections management, focussing on documentation and procedure when receiving a loan, or when loaning out an object ourselves.

We then had a very interesting session, also led by Claire, on conservation of objects in the museum collections, and the dangers of deterioration (and how to avoid them). Happily, objects at present in our store are being kept in a pretty good conservation environment; it’s not too warm (objects should be kept at quite low temperatures, with 5°C being the minimum), there are no windows (and so no dangerous UV radiation from sunlight), it’s dry (damp can of course lead to mould), there aren’t any pests (which can eat into various vulnerable organic materials such as woods, fabrics and paper), and the humidity is good (the ideal relative humidity is between 25% and 65%, optimum being about 45%, with higher numbers meaning more moisture in the air and the average outside RH being 75-90%). Good news for our objects then.

We discussed the need to keep objects clean, because dust can get ingrained into some materials, especially wood. However, as Claire pointed out, it is also important to remember to think about what stories we want the objects to tell, and thus how we want them to appear. For example, some dirt is evidence of use. This is particularly relevant when it comes to our medical collections, with lots of instruments, many of which were used in the nineteenth century, hardly being as shiny and gleaming as doubtless they once were. Likewise our physics instruments, made mainly of wood and metal, which were used in late nineteenth century classrooms. The odd bump or scratch on one of these serves to add to our appreciation of its use by generations of school children who we like to imagine interacting with the forces of physics, especially electricity and magnetism, with awe and excitement.

Depending on what we want to say with these objects through our exhibitions, we must consider, essentially, how clean we really want them to be. Nevertheless, modern dirt is bad dirt, and we should be ensuring objects are kept dusted and well wrapped. Metal objects are particularly susceptible to being permanently marked by fingerprints, and so gloves should be worn when handling them. As none of us are, or are likely to become, experts in restoring objects to any semblance of their former glory, we must rather see our job as one of preservation: whatever the state of the object we are presented with, that is how it should stay. We should do all we can to prevent curators of the future wondering whether a certain mark, scratch or discolouration is evidence of wear and tear, or simply of a less careful previous curator.

Emily leads a discussion about the theory and thinking behind putting on an exhibition.

At this stage, Emily took over to lead a session about the interpretation of exhibitions. In answer to her question of why we should put on exhibitions at all, we came up with several answers. A good exhibition brings people in to a museum, allows for the promotion of the institution and its collections, and encourages public involvement with what are essentially publicly owned collections. Some thought it important to challenge people, others saw a display as a useful pedagogical tool, teaching about a subject through presenting an object that the audience can study, in three dimensions, and relate to. Exhibitions can also be used to tie in with special events, and to get more money for the institution.

Putting on an exhibition will always involve a balancing of priorities; one group requiring consideration are the conservators, who would probably rather that everything stayed nice and safe in the store, and that nothing went on display at all. Any display entails some degree of risk to the artefacts. Another important group are the shareholders of the institution, who may require that a certain emphasis be placed on the story being told. The public, of course, want access to the collections, and what is wanted in terms of information may change depending on the objects and the audience. Ultimately, the organisers will also need to decide whether the objects they have in their collections will guide the shape of the exhibition, or whether some idea or ideal will lead them to seek to borrow other artefacts from elsewhere to help them tell their story.

Emily also pointed out that people have different ideas about what they want to get from an exhibit. In our subsequent discussion, we considered that some people want to be told a lot of information about the artefacts on display, some people want to be able to make up their own minds about what an object means, with minimal context given to them, and some people just want to look at pretty shiny things. In our case, we need to decide how best to present our objects and information about them in order to provide people with interesting stories about the history of science, technology and medicine here in Leeds.

As, unfortunately, Mark Steadman was unable to make it in to take a planned session on object handling (due to car troubles), we wrapped up the training morning about midday with a short taskforce meeting to update one another on the progress of our various projects. The morning’s activities were well received, and all the sessions were informative and well-run, and should provide all who attended with a good foundation for implementing future museum projects.

Embedding videos

Hi all, there are now 10 videos up on the channel.  I have to thank Dom for his Facebook publicity, which saw the number of views rocket within a couple of hours; I wonder if others might also do what they can to promote them by posting links to their chosen social networking outlets?

Secondly, could I suggest that those of us with blog posts on their objects edit those posts to embed their YouTube video into the text?  It will just pull everything together and make all our material more accessible.  See mine below.

Thanks!

Michael.

Hidden Histories videos

I am pleased to announce that the first 6 videos of the project are now up on YouTube on the museum channel, and can be viewed here:

http://www.youtube.com/user/hpsmuseumleeds

I have also made sure to put plenty of information on the channel itself.  Please leave me any feedback or comments you think relevant.

Thanks to all those who have taken part and been filmed so far, and to everyone else, I look forward to seeing you on the other side of the camera very soon.

Michael.