Monte Saint-Michel. Nebbia e sole

In 1897 the abbey church of Mont Saint-Michel got a new neo-Gothic spire, and a gilded copper archangel was hoisted to the top of it, four and a half metres of hammered Saint Michael with a sword, wired up to double as a lightning conductor. Signac was working on the rock that same year, painting it in a run of canvases under different weather before he went south to Saint-Tropez. The silhouette he was recording had just changed shape.

His own method was changing too. Six years after the death of Seurat, with whom he had built the technique of separated colour, Signac had given up the small dot for broader square touches laid side by side like tiles, which is what lets fog and sunlight share the same patch of canvas here. He spent those years writing a book that traced the whole idea back to Delacroix. It appeared in 1899.