Great Grandma had a big collection of antique kitchen tools. I brought this one home to show my kids. But I'm not sure exactly what it was used for. The base is made out of pottery. The base is 8 1/2 inches tall. The diameter is 6inches. The lid is wooden. There is ametal turning mechanism on the top that rotates a spatula like handle on the inside to stir whatever is in there. Does anyone know what this is?