Gethin Rees is Lead Curator for Digital Mapping at the British Library and a Sloane Lab Community Fellow. The following post was first published on the Digital Scholarship Blog of the British Library.
I have recently started a community fellowship working with geographical data from the Sloane Lab project. The project is titled A Generous Approach to Web Mapping Sloane’s Collections and deals with the collection of Hans Sloane, amassed in the eighteenth century and a foundation collection for the British Museum and subsequently the Natural History Museum and the British Library. The aim of the fellowship is to create interactive maps that enable users to view the global breadth of Sloane’s collections, to discover collection items and to click through to their web pages. The Sloane Lab project, funded by the UK’s Arts and Humanities Research Council as part of the Towards a National collection programme, has created the Sloane Lab knowledge base, a rich and interconnected knowledge graph of this vast collection. My fellowship seeks to link and visualise digital representations of British Museum and British Library objects in the SLKB and I will be guided by project researchers, Andreas Vlachidis and Daniele Metilli from University College, London.
The first stage of the fellowship is to use data science methods to extract place names from the records of Sloane’s collections that exist in the catalogues today. These records will then be aligned with a gazetteer, a list of places and associated data, such as World Historical Gazetteer (https://whgazetteer.org/). Such alignment results in obtaining coordinates in the form of latitude and longitude. These coordinates mean the places can be displayed on a map, and the fellowship will draw on Peripleo web map software to do this (https://github.com/britishlibrary/peripleo).
Figure 1. Web map using Web Mercator projection, from the Georeferencer.
The fellowship also aims to critically evaluate the use of mapping technologies (eg Google Maps Embed API, MapBoxGL, Leaflet) to present cultural heritage collections on the web. One area that I will examine is the use of the Web Mercator projection as a standard option for presenting humanities data using web maps. A map projection is a method of representing part of the surface of the earth on a plane surface. The transformation from a sphere or similar to a flat representation always introduces distortion. There are innumerable projections or ways to make this transformation and each is suited to different purposes, with strengths and weaknesses. Web maps are predominantly used for navigation and the Web Mercator projection is well suited to this purpose as it preserves angles.
Figure 2 Map of the world based on Mercator projection including indicatrices to visualise local distortions to area. By Justin Kunimune. Source Link Used under CC-BY-SA-4.0 license.
However, this does not necessarily mean it is the right projection for presenting humanities data. Indeed, it is unsuitable for the aims and scope of Sloane Lab, first, due to well-documented visual compromises —such as the inflation of landmasses like Europe at the expense of, for example, Africa and the Caribbean— that not only hamper visual analysis but also recreate and reinforce global inequities and injustices. Second, the Mercator projection has a history, entangled with processes like colonialism, empire and slavery that also shaped Hans Sloane’s collections. The fellowship therefore examines the use of other projections, such as those that preserve distance and area, to represent contested collections and collecting practices in interactive maps like Leaflet or Open Layers. Geography is intimately connected with identity and thus digital maps offer powerful opportunities for presenting cultural heritage collections. The fellowship examines how reinvention of a commonly used visualisation form can foster thought-provoking engagement with Sloane’s collections and hopefully be applied to visualise the geography of heritage more widely.
Figure 3 Map of the world based on Albers equal-area projection including indicatrices to visualise local distortions to area. By Justin Kunimune. Source Link Used under CC-BY-SA-4.0 license.