This is a picture of a Moniac (along with my son Jacob), a hydraulic computer, modelling an economy at a high level. It is a New Zealand cultural and scientific artifact, invented by Bill Phillips. Phillips was a New Zealand economist, but if you read his biography, you discover that before that, he was an adventurer. It is well worth reading about Bill, who was trained largely by observation and had a brilliant, critical mind, unusually coupled with a an inventor's belief in the possible.
This photograph was taken at the science museum in London. But you don't have to travel so far to visit this icon, as there is also one in the Reserve Bank building, in the small museum on the ground floor, which is open to the public. If you have some time between appointments next time you are there I recommend popping in.