Article by Erinna Cave and Corinne Mona

The Niels Bohr Library & Archives has proudly sponsored the Grants to Archives program since 1998. This program helps support work to make accessible records, papers, and other primary sources that document the history of modern physics and allied fields. It is open to any institution worldwide and has a deadline in autumn each year.

Chatsworth House Trust was one of the recipients of the grant in 2022 for its project to catalog the papers of Henry Cavendish. In this interview, Archivist Erinna Cave tells us more about the project.

This interview was originally published in the spring 2024 issue of the AIP History Newsletter. The project is now concluded; please see the bottom of this article for more information.

Corinne Mona: Please tell us a bit about yourself. What is your background? What is your job at Chatsworth?

Erinna Cave: My background is actually in law. I was a practicing barrister before re-training as an archivist. Since then, I have worked in several places with archival holdings including a museum, a local authority (municipality), and a large corporation.

My job at Chatsworth is that of Project Archivist. I catalog the collection of Henry Cavendish (1731-1810): a collection consisting of several boxes of papers. I also assist in the running of the wider archive: monitoring the studyroom when researchers visit to consult our collections, answering enquiries, and working on the other collections that the Trust maintains.

In non-working life, I love living in England’s beautiful Peak District (even on the wet days!), hiking its trails and exploring its summits.

Please tell us a bit about Chatsworth House Trust. What kind of collections do you have? Who are your typical researchers and visitors?

Chatsworth House Trust, a registered charity, was established in 1981 and supported by an endowment donated by the Devonshire family (the historic owners of Chatsworth) to preserve Chatsworth House, its collections, its garden and Chatsworth Park for the benefit of everyone. The Trust generates income from visitors and supporters to undertake an ever-expanding program of essential conservation and to fund an extensive learning program. The Trust is part of the wider Devonshire Group comprised of charities and businesses throughout the UK and Ireland. Chatsworth House is at the heart of the Derbyshire estate and attracts around 600,000 visitors each year.

The Devonshire collection is one of the largest and most significant private collections in the UK. It includes ceramics, furniture, jewelry, gems, an extensive library, metalwork, paintings, Old Master drawings, sculpture, textiles and (naturally) the archive. Within the archive, we hold family papers and papers from the numerous estates owned or once owned by the Cavendishes, along with papers from individuals associated with the family, such as the philosopher Thomas Hobbes or the gardener Joseph Paxton.

Our researchers and visitors are varied. We get many internal enquiries from the Devonshire Group: from Estates looking at land ownership to the gardens investigating the history of a particular plant to the retail outlets developing new products or branding. Our external visitors are academics, private researchers looking into family or local history, curators from other organizations and others. Any day could bring a new query in to our inbox on a topic that we have not focused on but is someone’s passion which is exciting!

The grant is funding the cataloging of the Papers of Hon. Henry Cavendish. Please tell us about the project and how it’s going.

The project is broken down into several stages. The first is to ascertain the material that we have in the collection; the second to catalogue it to acceptable international standards, making it accessible through our electronic catalog to researchers; and the third is to complete some preventive conservation work on the papers and repackage them appropriately so that they are preserved for future generations.

At this stage, I have been through the material in the main collection and have an idea of how it should be arranged and cataloged. I will now start entering the data into our catalog, describing each record in detail so that researchers will be able to see what material can be accessed. I hope to move on to searching for traces of Henry through our other collections, such as in the papers from the family lawyers and family letters written by other Cavendishes to or about Henry.

Who is “The Man Who Weighed the World?” Why is he important to the history of science?

Henry Cavendish (10 October 1731-24 February 1810) was the grandson of the second Duke of Devonshire. His father, Lord Charles Cavendish, having been a politician, pursued his own scientific interests. Lord Charles was a Fellow of the Royal Society and set up a laboratory and workshop at his home in Marlborough Street, London. Henry attended Cambridge before returning to live with his father in London, assisting him with his scientific work and developing his own interests. Henry was elected a Fellow of the Royal Society in 1760. His work spanned diverse areas of science: astronomy, magnetism, heat, chemistry, electricity, and mathematics. During his lifetime, he published little yet was feted for his discovery of hydrogen (as published in his papers Containing Experiments on Factitious Air, 1766) and his later great experiment to calculate the density of the earth (Experiments to Determine the Density of the Earth, 1798). The former discovery earned him the Royal Society’s Copley Medal, the society’s most prestigious award.

Another great discovery by Henry was ascertaining that water was not an element, but a compound of gases- the last of the ancient elements to be shown to be not in fact elemental. Henry’s investigations gave rise to a controversial priority claim between his supporters, James Watt’s heirs and the French scientist Antoine-Laurent de Lavoisier which raged throughout the 1830s to the 1850s.

After his death, an examination of his papers revealed the scope, depth and genius of his scientific work. His manuscripts showed that he had anticipated most discoveries about electricity that were to be “re-discovered” over the coming years, such as Coulomb’s Law. Subsequent scientists including Sir William Snow Harris and James Clerk Maxwell saw his manuscripts and were astonished at how advanced his thinking was.

Henry served on several significant committees for the Royal Society, contributing to the advancement of science by his work on the committees organizing the transit of Venus expeditions, protecting gunpowder stores from lightning (working with Benjamin Franklin), measuring the mass of the Earth through the attraction of mountains, and organizing instruments for expeditions to find the Northwest Passage. Henry’s letters shows that he corresponded with many leading scientists of the era, including Joseph Priestley, John Michell (who developed the instrument that Henry would use to measure the Earth’s density), Sir Joseph Banks, Nevil Maskelyne, Jean Andre Deluc, and William Herschel.

Henry had a reputation for being shy and uncomfortable in society, rarely joining in general conversation. He kept a strict routine in his lifestyle, dining twice a week with the Royal Society. He was meticulous with his experiments and focussed on detail, accuracy and precision. His papers are full of the repetition of experiments to accurately and precisely calibrate instruments. He rented two houses in London: one he used to house his extensive library, the other he used as a laboratory and observatory. His library eventually passed to the Dukes of Devonshire and forms a substantial part of the library housed at Chatsworth today.

How did you hear about the grant?

We heard about the grant through a colleague at the University of Manchester who successfully applied to the AIP for a project to catalogue the papers of astronomer Zdeněk Kopal. Having investigated the grant, we felt that Henry Cavendish’s papers would be a perfect candidate for this funding given their significance to international science.

Do you have a favorite part of the Collection? Has anything particularly surprised you or caught your interest as you’ve been working with it?

Unfortunately, the most surprising element so far has been an absence: an absence of any papers about Henry’s best-known experiment to “weigh the world”! There is not one scrap of paper about that experiment in the collection, save for the letters that he exchanged with John Michell talking about the idea. The absence causes me to wonder if the papers relating to that experiment, being particularly valuable, were syphoned off elsewhere before the collection came into the hands of the Dukes of Devonshire. Perhaps Henry destroyed them himself before his death? Maybe one of the many scientists who looked at his papers after his death decided to keep them for themselves? This is a question that I hope to get to the bottom of in the course of the project.

My favorite part so far has been trying to piece together any sense of Henry as a person. This is difficult as his life is his scientific endeavor. There are no papers of a more classic “personal” nature in the collection. He had a younger brother who suffered a terrible accident falling on his head out a window while the brothers were studying at Cambridge. I would love to find more material relating to the brothers’ relationship. This will require much trawling through the family lawyers’ papers and the papers of other family members. I will let you know what I find.

Is there anything else you want to share with us about your Grants to Archives experience, or anything about the project?

We were absolutely delighted to be a recipient of one of the AIP’s Grants to Archives as there are so few grants available which are exclusively dedicated to cataloguing archives. Grants like this make a huge contribution towards addressing our cataloging backlog and making information about our collections available to researchers.

In terms of the project, there is a lot of engagement with the work already. It’s hoped that we will include Henry in some of the program at Chatsworth shortly: watch this space!

Editor’s note: Indeed, since this interview occurred, we heard from Erinna Cave that she submitted the final report for this project, and the papers are now open for research; here is the press release with more details. Be sure to check it out and visit Chatsworth if you can!

Finally, here is a short video that Chatsworth produced about Henry Cavendish, narrated by Erinna Cave: