One of my routes takes me from Green Park Underground station to St James’s Square. There, after a spell prowling the metal floors of the London Library and perhaps retiring to a leather armchair to digest my researches (it’s extraordinary how many people read with closed eyes), I retrace my steps.

Twice on Piccadilly recently, I have been confronted by a blinding light. On Saturday, it was so intense that I had, once more, to close my eyes, nearly blundering into tourists in the Ritz arcade. A Jehovah’s Witness might have mistaken it for the Second Coming. You may say it was only the late-afternoon sun, but I’ve been puzzling about it. I don’t remember having observed such an effulgence before.

If I were a Luminist-one of the school of 19th-century American painters who believed the phenomena of Nature were an expression of divine will-I would think it meant something. But what? The streets of London are hardly paved with gold, but a golden light could be taken to symbolise its wealth. Or was it like the beam of light focused by a magnifying glass, a hint that this City of the Plain is about to self-combust? Deep waters.

On a material note, after years of building work, the new Underground station has been revealed: it’s much improved.

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