Rich - this is a shot tower. Shot Towers were used for making lead shot for guns. Molten lead dropped from a seive at the top was formed into spheres by surface tension as it fell. The tower needs to be high enough for the lead to start to solidify on the way down. A water tank at the bottom cooled the shot balls.
This tower now stands inside a shopping complex. The tower was heritage protected, so the developers solution was to turn it into a feature under the glass roof.
Nifty
