Balliol College Library is delighted to announce that a new collection, Trefethen’s Index Cards, is now available to the public on Epexio, our online platform for archival material. This unusual collection is the work of Lloyd Nicholas Trefethen FRS, Professor of Applied Mathematics in Residence, Harvard University. Professor Trefethen is also a Fellow of Balliol College and until 2023 was Head of Oxford’s Numerical Analysis Group. He deposited this collection with Balliol College in 2023.
The collection consists of roughly 1,200 4″ by 6″ index cards, each bearing a short piece of writing by Professor Trefethen. Trefethen began producing these index cards in February 1970, when he was 14 years old, in an effort to capture some of his recurring thoughts and ideas. The collection currently includes all of the index cards up to the end of 2025, but Trefethen continues to produce more to this day and the additional cards will all eventually be added to this collection.
The index cards are a collection of Trefethen’s thoughts, observations and questions, relating to a wide variety of topics ranging from fatherhood to language to religion. These writings vary not only in topic but in tone, with some entries being light-hearted, such as those concerning word play or day to day life. Others, such as those concerning morality or the threat of nuclear conflict are often deep and serious.
In some ways, the collection almost resembles a diary. The reader gets an intimate picture of Trefethen’s thoughts and opinions as they develop over time, recording his changing interests and ideas from his teenage years all the way through his long and eventful career. It gives the reader a remarkable insight into Trefethen’s intellectual development and his evolution as a scholar.
In addition to the insights that the collection can give us into Trefethen as an individual, the collection also provides a unique window onto the intellectual, cultural and technological developments of the late 20th and early 21st centuries as perceived by this unusual scientist and scholar.
The collection has been fully digitised and images of each card can be seen on Epexio as well as transcriptions of the full text of each card and a variety of other information. The cards are organised chronologically, but the collection is searchable as a whole or within a specific date range, or users can filter it by subject.
You can find the full collection here: https://balliol.epexio.com/records/BCHC/PP/TREF
The text of some of the most recent cards can also be found at Professor Trefethen’s WordPress here: https://trefethen.net/
Historic Collections @Balliol 