Maths in Museums: Bolsover Castle

For years I have been periodically prompted to think "ah yes, must go there one day" by signs for Bolsover Castle as I pass through the vicinity of Junction 29A on the M1. That day, as all things must surely do, finally came to pass on Monday 11th August, 2025^[1].

Bolsover Castle © 2025 by Tom Briggs is licensed under CC BY-NC-SA 4.0

As with all posts in the Maths in Museums series, it is not for me to tell you how or when to visit, how much it costs, or even much about the history of the site (though some will surely creep in). All of that can be left to English Heritage, who are its current custodians. Our purpose here is to uncover some of the opportunities for mathematical exploration that I spotted during my visit^[2]. As with most museums and galleries, there's no interpretation at the site that will help you to structure any exploration of these ideas.

Bolsover Castle is the ruins of a 17th century castle built on the ruins and earthworks of a 12th century castle. My immediate mathematical thought, then, was of a simple comparison of the time between the original castle and the rebuild, and the time between the rebuild and now: telling me that something is from the 12th century or from the 17th century doesn't mean much to my brain, but comparing the length of those two periods gives me a mild case of what I'm going to call time-vertigo.

Scale Models of Bolsover Castle © 2025 by Tom Briggs is licensed under CC BY-NC-SA 4.0

One of the first things I noticed as we passed through the massive South-East Gate into the Great Court was a tactile scale model of the castle and its grounds (bottom, in the collage above). I love a scale model because they help me to shrink things down to a point where an overview fits into my brain. There was another - of 'The Little Castle' (top, in the collage) - elsewhere^[4]. Not only are scale models generally brilliant, they're also excellent routes into some mathematical exploration: measure things on the model and work out their real-life size; measure a real-life thing (yourself, maybe) and figure out what it would look like in the model. Or, when the scale isn't given^[5], measure a real-life thing and its scaled counterpart and work it out from there! An image of the earliest-known architect's design for a kitchen range, destined for Bolsover castle, (including annotations with units of measurement) provides a nice alternative angle on this general theme. And another: it's difficult to tell the scale of the building in the image at the top of this post, but I commented that it felt like it was made for giants, which made me wonder how big those giants would be if their height and and the height of the entrance way were in the same proportions as my height and my front door at home.

Browsing the guidebook tells me that Bolsover has been subject to at least two major sieges in its past. A good siege always reminds me of Storming the Castle, a maths+history learning activity offered 140 miles away at Norwich Castle, could easily be plundered for ideas that would work at any castle. But siege warfare in general provides a feast of mathematical themes just waiting to be explored at all educational levels, from simple resource management problem solving for primary school students, up to investigations of projectile motion for students at A-level and beyond.

It's always good when there's a real person you can hang a mathematical story on, so I was absolutely stoked when I wandered into a room and came face-to-face(less) with none other than...

Ada Lovelace Mannequin at Bolsover Castle © 2025 by Tom Briggs is licensed under CC BY-NC-SA 4.0

... only Ada blimmin' Lovelace! She's there as part of a collection of dressed mannequins that form an exhibition called Fame, Fortune and Fashion: The Women of Bolsover^[6]. Disappointingly, the banner accompanying Countess Lovelace's mannequin doesn't explain what her connection with Bolsover is, and the best I could find was that her final resting place is a church about half an hour away by car. Nevertheless, Ada Lovelace is well known as an important figure in the history of computer science (which is often mentioned, including in her panel here) and mathematics (which is often omitted, including in her panel here)^[7]. This habit of celebrating famous historical figures' achievements except the maths^[8] means that sometimes a little bit of digging can pull out a mathematical connection where one is least expected.

A couple of quickfire bits of maths at Bolsover Castle to leave you with: one panel drew attention to circular themes in the garden, explaining that the symbol represented perfect love in Renaissance philosophy, providing an opportunity to explore the not inconsiderable links between geometry and all sorts of things like religious symbolism and superstition; and the shapes formed either on purpose or by accident in architectural designs where form and function combine, such as the roof timbers shown in the image below:

Form Meets Function in Roof Supports at Bolsover Castle © 2025 by Tom Briggs is licensed under CC BY-NC-SA 4.0

As always, if you'd like more museums and galleries (including Bolsover Castle!) to bring their mathematical stories to the surface, then consider letting them know when you provide feedback after a visit: organisations in the cultural sector really care about visitor feedback, and the only reason that most of them don't do anything to help you play with maths while you're there is that they don't know you want them to.

Did you enjoy this post?

If you'd like to see more posts like this, summarising the maths I've found during a visit to a museum (or gallery, etc), then consider doing one or more of the following:

• (and don't forget to let me know what I did that was worthing tipping me for)
• If you'd like me to write a similar post about a specific museum or gallery then commission one.
• If you work for a museum or gallery and you'd like some help telling a mathematical story, get in touch.

Footnotes

1. I realise that this sounds a bit like I'm saying literally all things come to pass on Monday 11th August 2025, which clearly isn't the case. [back]
2. I'd be very interested to hear about the maths links that you spot during your own visit^[3], or that you think of while you're reading this. If you're screaming in your head "BUT WHY HAVEN'T YOU MENTIONED [mathsy thing]!" the answer is that it's because I haven't thought of it, so you'd be doing everyone a favour by bringing it up in the comments (or maybe even writing a guest post). [back]
3. To Bolsover, yes, but also anywhere else. [back]
4. In The Little Castle, if you're interested. [back]
5. Naughty! But sometimes useful, in this context. [back]
6. The only 'official' project page that I could find was this one which lists other women represented in the exhibition but, oddly, doesn't include Ada. [back]
7. She gets more than a mention on both counts in my book, The Mathematicians' Library. [back]
8. Another example, in case you're not convinced that this is a thing that happens: ask the next ten people you meet if they have any idea of who Florence Nightingale is and what she did that was so important, and tell me (a) what fraction of them know something about her and (b) what fraction of them mention anything to do with statistics. [back]