this is known as the Falstaff weather ball. The ball on top is lighted and is supposed to glow one color or another depending on weather. It was briefly in operation, in anticipation of some restoration of the building complex below, but seems to have been abandoned again since Hurricane Katrina (8/29/05). The area of the old Falstaff Brewery was heavily flooded by levee breaches after said hurricane and this is one of the areas where the brackish water remained the longest (almost two weeks).
