This stoneware jug was discovered in the bottom of a 19th-century cistern and functioned as an early water filtration system in downtown Albany. The cistern collected rainwater and cleaned it as particulates settled to the bottom while going through a series of baffles, or panels used to control water flow. In the final stage of the process, water was filtered through a layer of charcoal before entering the jug through small holes. A pipe inserted in the top of the jug was then used to draw the clean water to the surface.