Hi Adam. Griswold listed them as "Maslin Shaped"(in several old reprinted catalogs) Griswold stated -"These kettles are particularly serviceable for canning, preserving, and jelly making.
Why is it called a Maslin? Well, without getting too involved, thought to be of British origin (maslin was an archaic term for "mixture"), they used them to cook down a mixture of grain....think- [smiley=Drunk.gif] (mash), and then the shape was popular for canning, jelly, etc. FWIW.