James Cheshire of UCL's Centre for Advanced Spatial Analysis has made the above map, depicting London's fire engine callouts between January and December, 2011. The map represents 144,000 separate incidents, and shows the distance the travelled by the fire engines to each one. As you can see, the results are unexpectedly beautiful.
Does it tell us anything? Perhaps not, but at a time when proposed cuts to fire stations are likely to impact the service's response time, it's a useful indicator of the sheer number of callouts our firefighters have to deal with, and how vital the service they provide is.
Read James' blog post for a further explanation of his methodology.