I spent a couple of hours yesterday wandering around the Degas exhibition at the Royal Academy.  He's justifiably famous for his ballet imagery but Degas was also an accomplished  photographer and there were lots of his prints and negatives on show.  Degas made portraits of friends and members of his family, as well as of himself, and also used photography as the basis for some of his paintings.  Of course I couldn't take any photos in the exhibition but in the courtyard outside there's a 10m high model of Tatlin's utopian Monument to the Third International, an unrealised structure designed two years after Degas died.  These brass figures are about 5cm high, giving some idea of how the 400m high tower would have soared into the sky above St Petersburg.