These containers vary greatly in size, but are typically glazed white, flat-bottomed, round porcelain containers with unglazed bottoms and fluted exterior borders.
The construction is similar to their building these waters' more common flat-bottomed rectangular rowboat used for fishing and river crossing of local goods.
An extension of the spirit level is the bull's eye level: a circular, flat-bottomed device with the liquid under a slightly convex glass face with a circle at the center.
An extreme example of tumblehome architecture, she sported a conventionally shaped superstructure mounted on a wide, flat-bottomed, turbot-shaped submerged hull or pontoon.
