The illustrative diagram shows three types of cooking equipment.
Overall, what stands out from the diagram is that the changes are depicted trough three main stages: A, B, C. The diagram illustrates not only their stages of development but also what they were made of.
The first phase A was made of stone, it was a long cylindrical pot, with a narrow neck and a small opening. Phase B demonstrates significant improvement, with cooking shield made of clay, which protects fire from water and wind.
In contrast, phase C shows the major development, as it is made out of metal, while others made of natural materials. On the pot there are supports and handle which makes transportations easier. There is a door which needs to be closed while using the pot, made to control ashes and air. The top grate is needed for charcoal, which is surrounded by a clay lining and makes the design modern.
