British Museum blog

Lost Change: mapping coins from the Portable Antiquities Scheme

coin visualisation
Daniel Pett, ICT Advisor, British Museum

Today sees the launch of Lost Change, an innovative and experimental application that allows coins found within England and Wales and recorded through the British Museum’s Portable Antiquities Scheme (PAS), to be visualised on an interactive, dual-mapping interface. This tool enables people to interrogate a huge dataset (over 300,000 coin records can be manipulated) and discover links between coins’ place of origin (the issuing mint or a more vague attribution if this location is uncertain) and where they were discovered and then subsequently reported to the PAS Finds Liaison Officers.

While much of the the data is made available for re-use on the PAS website under a Creative Commons licence, some details are closely guarded to prevent illicit activity (for example night-hawking or detecting without landowner permission) and so this application has been developed with these restrictions in mind. An object’s coordinates are only mapped to an Ordnance Survey four-figure National Grid Reference (which equates to a point within a 1km square), and only if the landowner or finder has not requested these to be hidden from the public.


The distribution of coins is biased by a number of factors (a project funded by the Leverhulme Trust is looking at this in greater depth) which could include:

  • Whether metal detecting is permitted by the landowner, or the topography makes detecting difficult
  • Soil type and land use
  • Whether there is an active community of metal detectorists within the vicinity


The tool is straightforward to use. The left hand pane holds details for the place of discovery; the right hand side holds details for the place of issue, the mint. These panes work in tandem, with data dynamically updating in each, depending on the user’s choice. A simple example to get going is this:

  • Click on “Iron Age” within the list of periods
  • Within the right hand pane, click on one of the three circular representations and this will highlight where the coins from this mint were found in the left hand pane. The larger the circular representation, the more coins from that mint have been recorded.
  • If one clicks on any of the dots within the left hand pane, these are selected and an overlay in the right hand pane allows dynamic searching of the PAS database.

The PAS intends to build on this project at a later stage and will be seeking further funding to enable this to happen, with many more facets of discovery available to query the dataset.

Lost Change was funded through a £5,000 grant from the CreativeWorks London ‘Entrepreneur-in-Residence’ programme.

The PAS is grateful to Gavin Baily and Sarah Bagshaw from Tracemedia who developed the application, and everyone who has contributed to the PAS database.

If you have any feedback on the project, please contact the PAS via

If you would like to leave a comment click on the title

Filed under: Portable Antiquities and Treasure, , , ,

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 14,939 other followers


Follow @britishmuseum on Twitter

British Museum on Instagram

You can now discover thousands of British Museum objects in partnership with @googleartproject at We’ve asked staff members to highlight their favourites and explain what makes them special. Chris Spring, Curator of Africa Collections, describes why he finds the ‘Throne of weapons’ so powerful. ‘This war memorial celebrates the ordinary people of Mozambique, many of them unarmed, who stood up to a culture of violence. It represents both a human tragedy and a human triumph. The Throne's essential humanity is suggested right away by its anthropomorphic qualities - it has arms, legs, a back and most importantly a face - actually two faces. My first reaction was that these faces are crying in pain, though they could also be seen as smiling faces finally freed from conflict. These anthropomorphic qualities also link it immediately to the arts of Africa, in which non-figurative objects such as chairs, stools, weapons, pots etc are seen as - and described as - human beings. The Throne has toured the world, taking its message of peace to schools, churches, shopping centres and even prisons – and of course, to museums and galleries.’ #MuseumOfTheWorld We’re celebrating our partnership with @googleartproject, and have asked curators to tell us about their favourite objects. Hugo Chapman, Keeper of Prints and Drawings, explains why he chose this chalk drawing by Michelangelo. ‘One of the things I love about drawings is the way they sometimes allow a glimpse into the private, behind the scenes world of an artist, one unseen in finished works in paint or stone. An example of that is a red chalk drawing by Michelangelo of grotesque heads in red chalk that reveal that the Florentine Renaissance artist had a lively, if caustic, sense of humour. The three heads were probably drawn to amuse but at the same instruct his pupils, as the three studies show how slight changes can radically alter the reading of an image with the character and mood of each figure (paranoid anxiety; vacuous joy; and depressive gloom) signalled by the position and erectness of their donkey-like ears.  I wish my ears were as expressive.’ Discover many more incredible works of art in the Google Cultural Institute at

#Michelangelo #art To celebrate our partnership with @googleartproject, we’ve asked members of British Museum staff to highlight their favourite objects and explain what makes them special. Jill Cook, Deputy Keeper of Britain, Europe & Prehistory, chose this stone chopping tool from an early human campsite in Olduvai Gorge, Tanzania. ‘Holding this 2 million year old African tool in my hand I am reminded that whatever differences exist between people now, we are united by our common origin in Africa. The discovery of this piece by Louis Leakey in 1931 began to change our understanding of what makes us human. It illustrates the beginning of a transition from an ancestral ape that walked upright on two legs within the confines of a limited ecological niche to humans with more complex brains capable of changing and eventually dominating the world around us by making tools and weapons. This chopping tool is one of the seeds from which all human cultures and societies have grown.’ Discover the stories of thousands of objects in the Google Cultural Institute at

#MuseumOfTheWorld In Victorian England many people were fascinated by their past, and the ancient tribal leader Caratacus (also spelt Caractacus) was adopted as a symbol of national pride and independence. Like Boudica, Caratacus resisted the Roman invasion of Britain. Although he was eventually defeated, he earned a reputation as a noble and worthy foe. The Victorian sculptor J H Foley portrays him here standing triumphant, the embodiment of courageous English spirit. See this incredible #Movember moustache in our #Celts exhibition, until 31 January 2016.
J H Foley (1818–1874), Caractacus. Marble, 1856–1859. On loan from Guildhall Art Gallery/Mansion House, City of London. Some more #Movember inspiration! Here’s the Museum’s security team from 1902 photographed on the front steps. They include officers from the Metropolitan Police, and the London Fire Brigade (identified by their flat caps). We’re celebrating #Movember with Museum moustaches great and small. Here’s a #Movember fact: Peter the Great of Russia introduced a beard tax in 1698 and this token was given as proof of payment!

Get every new post delivered to your Inbox.

Join 14,939 other followers

%d bloggers like this: