Dr Geraint Owen and Emily O'Reilly: George Bellas Greenough's geological map of England and Wales

Dr Geraint Owen and Dr Emily O'Reilly are taking over Swansea Museum on Thursday 5 November, for a double-bill that looks at one of the museum's own treasures from two very different angles. The subject is George Bellas Greenough's geological map of England and Wales, and the evening is split into two talks.

The first half is the historical side of things. Dr Owen will be talking through the background to Greenough's pioneering map, which was one of the earliest attempts to chart the geology of England and Wales. It's the kind of thing that sounds like a niche bit of history until you realise how much of our understanding of the landscape started with maps like this. If you've ever wondered how we actually began to map the ground beneath our feet, that's where this part kicks in.

The second half shifts from the history of the map to the physical object itself. Dr O'Reilly will be talking about the conservation of the museum's own copy, a project funded by the Royal Institution of South Wales. It's a different kind of story — less about the 19th-century science and more about the practical, painstaking work of keeping an old map from falling apart. Between the two, you get the whole life of the thing: how it was made, what it meant when it first came out, and what it takes to make sure it survives for another century.

Both talks are part of the Royal Institution of South Wales's long-running programme, which has been putting on talks and events for its members and the public since 1835. The cycle runs every year from September to May, with most sessions held at Swansea Museum (Amgueddfa Abertawe), open to everyone and free of charge. This one starts at 6:30pm on Thursday 5 November, so you can catch both halves in one go.