Martin (1789-1854) was an extraordinary man - bipolar, a rationalist who specialised in religious scenes, a devoted amateur scientist: he achieved great success at the time as a painter, but would really rather have been an engineer! - who was derided by the art establishment for being too populist and entertaining. His paintings were Romantic in style: huge vistas of beetling mountains; vast and distant cities evoking a past of unimaginable grandeur; drama and destruction; lurid colours. And lightning - I lost count of the number of scenes taking place in an electrical storm. He painted Things Blowing Up (Pompeii and Herculaneum, Sodom and Gomorrah) and The End of The World, Heaven ... and Hell.
Despite his current obscurity, he was an immense influence on the Pre-Raphaelites, on Victorian engineers, and on film-makers from Cecil B de Mille to Ray Harryhausen to George Lucas. I can see echoes of his style in modern fantasy paintings of lost or futuristic cities.
This was one I was most impressed with - it doesn't show up well online, but in the flesh you can look right down those colonnades at the back, for about a mile.
I've never seen a painter who gives a better impression of depth to his landscapes. They're huge in scale, yet so detailed it feel like you could fly into his vistas.Though you might not want to, given all the lightning and the falling rocks ....
The exhibition runs until 5th June. Entry is free.