It stands over six feet tall, comprises of a number of plastic tanks and tubes through which coloured water flows. Linked to the tanks are gauges, sluices, pulleys and felt tip pens. What they are looking at is a magnificent piece of Kiwi ingenuity created by Professor Bill Phillips (of the Phillips Curve fame), known as the Moniac machine. It is a dynamic model of a working economy.
See also:
Wikipedia entry on analog computing
(via OVO)