This is a fantastic Mayonnaise churn. It is just like the daisy butter churns but on a smaller size. It has a mechanical crank on the top that turns the paddle inside of the jar. It is a very neat old piece. No damage of any kind. It is 12 1/2" tall and 4" across the bottom of the jar. The top is can iron and the handle is wooden.
J in a square………Jeannette Glass Company, Jeannette, Pennsylvania (1889-1983). Exact period of use of this mark is unclear …….. perhaps 1920s-1960s.