Yesterday was much more interesting. Richard & I went to see Ghost Forest in Trafalgar Square. It's an exhibition of tree stumps from rainforest trees in Ghana. Some of the trees had been felled sustainably (every tree in the rainforest there is numbered, and you can only take a certain quota of trees from a particular area in a 40 year period), others had fallen naturally. It was particularly useful to have the exhibition there because Nelson's Column is a similar height to the mature trees, so you had an immediate reference for the size of them when living. Also the plaque alongside each tree had a simple graphic comparing it to Nelson's Column (like when blue whales are compared to London buses, or in a video game info screen where you see size of monster compared to your character). Richard took lots of photos and I shall prod him until they go online.
Today the exhibition was being taken down, and sometime this week the trees are going to Copenhagen for the climate change summit. I don't know if there is a comparable building to be a size reference there.
I like the story about the Denya tree not wanting to leave the ground.