...I can post this. Surprisingly, for my mobile telephone, the quality isn't that bad. Any hope that I had of not having to explain what the image is of however still went out of the window because I didn't have a wide enough angle lens to get all the text in.
The trough has "Metropolitan Drinking Fountain & Cattle Trough Association" engraved alongside it. I found it in Hyde Park, and was amused.
I wonder what sort of person has "member of Metropolitan Drinking Fountain & Cattle Trough Association" on their CV? And does anyone know what the association actually does, beyond providing this key facility in the centre of London's biggest park?