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Darwin Correspondence Project

Epsilon: building a collaborative digital framework for c19 letters of science

Arago to Young pc sized.jpg

Letter from François Arago to Thomas Young
Courtesy of the Royal Society

ƐPSILON is both a research consortium and a developing, flexible, technical infrastructure for recreating the network of practitioners who expanded scientific knowledge in the long nineteenth century.  It will promote and support the digital creation, delivery, and preservation of scientific correspondence. Designed to link letter-texts from multiple sources for cross-searching and analysis, Epsilon will open up c19th science letters to the next generation of researchers and the widest possible public audience.

Its founding partners are:

A beta version of the site was demonstrated at the History of Science Society meeting in Toronto in November 2017. We expect it to be publicly accessible in 2018.

ƐPSILON is being designed to:

  • Maintain the independent identity of ongoing projects
  • Recognise the right of the originator to be identified
  • Accept material in multiple formats
  • Offer different levels of controlled access

And to take texts, metadata, and images from:

  • Completed and ongoing born-digital projects
  • Orphaned digital projects
  • Print only projects, completed, in progress, in and out of copyright
  • Print and digital projects in various formats
  • Ebook publications
  • Individual digital transcriptions of letters created by scholars
  • Crowd-sourced transcription from digitised images

How? We map letter data to TEI P5 XML encoding using the <correspDesc> metadata exchange element set. Advice on conversion and on using XML as an editing format is available.   Search is powered by XTF, an open source tool.





In this section:

Interested? We would like to hear from you.

If you would like updates about progress on ƐPSILON and to be notified when it goes live, please email us at with a request to be added to the Epsilon mailing list. For information about how we handle your personal data, please see .

Why ƐPSILON? The fifth letter of the Greek alphabet is used as a variable in almost every branch of science.  Its range of meanings include ‘set membership’, ‘elasticity’, and an ‘arbitrarily small positive quantity’.  And it also stands for ‘Epistles of Science in the Long Nineteenth century’.

ƐPSILON is funded, via the Darwin Correspondence Project and Cambridge University Library, as a publicly accessible platform, and as a repository for accepted TEI XML encoded data.

Have letters? Have ideas? Please join us.