Not exactly cookware, but related to my own interests.
Here is a size 0 glue pot I restored recently. It is marked Marietta PA along one side of the rim, and 0 with a raised “B” mark on the other. The small pot also has what looks like a raised 0 on the bottom of it. There is a gate mark across the bottom of the larger pot.
Hide glue granules are mixed with water in equal volumes in the small pot. Water is heated in the larger pot, creating a double boiler to heat and melt the hide glue into a useable product.
The fourth photo shows two musical instruments old enough to have been glued together using hide glue prepared in a pot like this one.