This superb large yellow ware mixing bowl has a smooth finish inside and out, appearing never to have been used. The only imperfections I can find are in the manufacture. See photos. 

The bowl is heavy with the iron in the base. 2.514 kg

The angled rest in the patent design of the base allows the bowl to be tipped and remain stable whilst mixing the ingredients.

Patent number 491517. I believe this was 1939