Category Archives: Technology

Maps on the radio

Two members of the Map Room team have recently been featured on WRFM, a local radio station based in West Oxfordshire. Science on the Radio is a weekly show, interviewing local experts across a range of fields connected with the sciences, presented by Nina Morgan and Grant Grindley. Broadcast every weekend, the show is also available online as an on-demand podcast.

‘Fascinating Maps‘ is a recent episode featuring Nick Millea, in which he talks about the 3D facsimile of the 15th century Gough Map of Great Britain (MS Gough Gen. Top. 16), recently produced by the Factum Foundation in Madrid. Nick explains that recent high resolution 3D recording of the map has revealed pinholes invisible to the naked eye, indicating that the map is a copy of an earlier map which does not survive. The 3D scanning unusually included the reverse of the map too, allowing confirmation that the pinholes only appear on the front of the map. Identical in size to the original, the facsimile has already proved useful for teaching and displays.

The Gough Map facsimile on display with other collections at a 'show and tell' event at the Weston Library.
The Gough Map facsimile on display with other collections at a ‘show and tell’ event at the Weston Library.

In ‘Digital Mapping‘, Martin Davis explains how some of our maps are being made available online via Digital Bodleian, and also why the digital maps we use every day pose new challenges for the library. While spatial analysis is something that we tend to associate with digital technology, such as Geographic Information Systems (GIS), Martin explains that the origins of these techniques predate digital technology altogether; for example in the work of the 19th century epidemiologist John Snow on the spread of cholera.

Science on the Radio is broadcast on Saturdays at 10am and Sundays at 6pm, and available any time via wrfm.co.uk.

Do [not] touch

People have always tried to make sense of their surroundings and plot where they are in the world, often in graphic form. Maps are inherently two dimensional but efforts have been made throughout time to create three-dimensional tactile maps. Primarily they are aimed at visually impaired users but they can also serve to understand relief and the environment in a holistic way. It is unclear when tactile maps started appearing but this lovely example of England and Wales is the earliest in our collections, produced in 1925. It primarily shows relief and rivers but also locates major towns but does not name them.

The development of tactile writing systems really took off in the 19th century with the development of basically embossed versions of roman letters, such as the Moon System but alongside was the use of a logical system of dots representing the letters such as braille.

This globe, which is undated but looks like it was made in the 1960s, uses prominent dots to depict capital cities in Europe but also a chain of mountains in Asia which must be confusing.  You can also see the rivers have been exaggerated and the equator marked to aid orientation.

Tactile maps conventionally were made using thermoforming or vacuum forming which uses heat or a vacuum to fix a material such as plastic or paper over a mould to create a stable physical object. These are very successful but they come with their downside – unlike paper maps they cannot be folded up and put in your pocket. The Royal National Institute for the Blind produced several maps with the Central London map as a typical specimen. With embossed roads and braille labels it is limited in detail so what its purpose is unclear. Was it produced for reference or as a wall map?

What is the future for mapping for blind or visually impaired people? Much work has been done by tech companies with smartphones and hand-held devices. Google Maps can speak directions and even tell you where safe road crossings are while you are using it. Haptic technology is used to generate a hybrid tactile map – for example the signal from your fingers will cause the map to vary when you cross a boundary, such as a road; or come across a symbol, maybe a bank. Although 3D printers can also be used to create maps but do not overcome the portability issue.

The library has a several tactile maps in the collection but this one was particularly challenging as it had no text to identify it. Coming originally from the MOD sample collection it has a red acquisition stamp and a tentative “Torquay” in ball point pen. I could not identify it with a modern map of that area so bit the bullet and tried transliterating the braille labels. It turned out that it needed turning around and it represents the Goswell Road/City Road area of Islington in London!

 

 

 

 

 

 

 

 

The Lake District’s topography lends itself very well so this is an attractive example. Designed as a hanging wall map in four sections it has been executed beautifully with using wooden strips glued together which have been sculpted to form the peaks and trough: shorelines, rivers and names have been burnt in to orient the sighted.  Entered into the BCS Awards which not only is it easy on the eye, it has a beautiful feel demonstrating that this is inclusive and appreciated by everyone not only as a map but as original creative piece. The perfect example of aesthetics and technique.

 

England and Wales. [S.n., S.l.], 1925 C17 (220)

A simplified system of embossed reading for the use of the blind : invented by WIlliam Moon, LL.D. &c. [London] : Moon Society, 1937 Rec. c.185

[World globe in braille]. (BR) B1 c.492

[Torquay]. [London] : [Royal National Institute for the Blind], [1979] SP 55

Central London. [London] : Royal National Institute for the Blind, 1970. SP 54

Lake District National Park. [Sheffield] : From the Workshop. BCS Award 2019 51

Mapping the recent past – electronic Legal Deposit

If you want to see what your town looked like 50 years ago, or even 150, the Map Room can find you a detailed Ordnance Survey map to answer the question. And if you want a really large scale plan showing the same site in the present day, you can buy one via an agent for OS Mastermap. But what about the period in between?

The OS map extract above shows Stratford-upon-Avon in 1889 at a scale of 1:2500. Maps at the same or larger scales continued to be published, updated at intervals, until the late twentieth century. In the 1990s, the OS stopped producing printed maps at the largest scales of 1:10,000, 1:2500 and 1:1250. Present day large scale mapping continued to be produced in digital format, and could still be purchased, but each time the data was updated the previous version was lost. There was a danger that recent history would disappear into a black hole. If a researcher in 2022 wanted, for example, an OS Mastermap of Kendal from 2012, what would they do?

The Legal Deposit Libraries – of which the Bodleian is one* – sprang forward to fill the breach. Working with partner organisation thinkWhere, they negotiated a scheme for the OS to deposit an annual digital “snapshot” of large scale mapping across the whole of Great Britain from 1998 onwards. Northern Ireland, which has its own mapping agency, soon followed suit. The dataset is updated annually. It was an early example of electronic Legal Deposit, preceding the official eLD which began in 2013.

What is electronic Legal Deposit? Under Legal Deposit legislation the Bodleian Libraries, and the other LDLs,  are entitled to a copy of every item published in the UK. Legal Deposit of printed materials has existed in some form since 1662, and thousands of the books, maps, serials, and printed music items in the library are here as a result. Electronic Legal Deposit was based on this; it came into force in 2013 and since then many published items have been deposited in electronic rather than print format. You can read more about it here on the Electronic Legal Deposit Libguide. In most cases, electronic Legal Deposit items are listed on SOLO and can be read on any Bodleian Library reading room computer.  Maps deposited on electronic Legal Deposit usually require specialist viewing software, and can be seen on a dedicated terminal in the Rare Books and Manuscripts Reading Room of the Weston Library. You can log in using your Bodleian Libraries username and password. Extracts can be printed using your PCAS account.

This has recently been updated with a much wider range of maps; as well as the large scale OS maps described above you can see a whole array of different maps of the UK here. There are detailed town plans by XYZ Maps and The Clever Little Mapping Company, large scale coastal charts by Antares, and a wealth of cultural information. There is information from Historic England showing locations of all the listed buildings geographically plotted with links to the website, descriptions and images; Historic Environment Scotland and Welsh preservation organisation CADW show similar information for Scotland and Wales. Also included are World Heritage sites, protected monuments, battlefields and shipwrecks.  The map below shows the locations of listed buildings in Portsmouth.

The maps so far are almost exclusively for areas within the British Isles, but the system is set up to give access to maps from anywhere in the world via a map interface. As an increasing amount of publication is now digital rather than printed, this can only grow.

 

*The other LDLs are the British Library, National Library of Scotland, National Library of Wales, Cambridge University Library and Trinity College Dublin, in case you were wondering.

The shortest distance between two points

We came across this map, on a very unusual projection, while processing a previously uncatalogued set of nineteenth century French sea charts produced by the Dépôt des cartes et plans de la marine. Most are standard nautical charts, but this one – part of a set of three – is extraordinary.  The world appears to have been turned inside out; the chart is centred on the central Atlantic, and the land masses are progressively larger and more distorted the further they are from this point. The other two charts represent the Pacific and Indian Oceans in the same way.

The title makes the chart’s purpose clear: ‘Carte pour la navigation par l’arc de grand circle’. A great circle is, technically, the point at which the surface of a sphere intersects with a plane passing through its centre. In practical terms, a great circle drawn on the surface of the Earth between 2 points will be the shortest distance between those points (the Earth is not, of course, a perfect sphere, but it is close enough for this to be of use).

Navigational charts are traditionally drawn on the Mercator projection. This has the great advantage of showing a line of constant bearing (rhumb line) on the Earth’s surface as a straight line on the map. This is the simplest course to navigate, as mariners have known for many hundreds of years, but it is not the shortest. The shortest route is a great circle, and this requires constant adjustment of direction to stay on course. Sailing ships were limited by the challenges of winds and currents, and early steam ships by the need to refuel, but from the 1870s this principle began to have more practical applications. A straight line drawn on this orthodromic chart is a great circle course between the two points it connects, enabling navigators to plan their great circle journeys relatively easily. These charts were published in 1879. 

Charts of this sort do not appear to have passed into common use, and there could be several reasons for this. For one thing, the difficulties of plotting a great circle course are sufficient to outweigh the advantages for all but the longest ocean crossing journeys. Mariners continued to use rhumb line navigation well into the late twentieth century, by which time GPS systems had come into use. When a great circle course was followed, for sea or air travel, it was calculated in advance, sometimes using a chart of this sort. The course would then be plotted onto a Mercator projection chart where it was easier to follow. 

The usefulness of great circles can be seen most clearly on a modern map of long distance air travel. This is why aeroplane routes from, say, London to San Francisco always appear oddly curved when viewed on a map, with the route going much much north than you would expect. This is a great circle course, and the shortest way to connect two distant cities. A demonstration can be seen on this useful site http://demonstrations.wolfram.com/GreatCirclesOnMercatorsChart/.

The charts were created by Gustave Hilleret, a naval lieutenant and teacher at the École supérieure de guerre navale, who also published books on navigation. The projection is the Gnomonic projection with Equatorial aspect; the charts’ Bodleian shelfmark is B1 a.61/1 [39-41].