I ran across this little tidbit while I was browsing through some of Bruce Ferrini's manuscript leaves. Dimensions are listed below.

m = 2 3/16 inches, best approximation.

Lisa Abrahams of the Gallery was kind enough to give me some background information about it:

Lisa:

Expertise on the pots is as follows:

DESCRIPTION:

small ink pot in beige stoneware, probably made by apprentice potters, found
in a dig in the Beauvaisis (area around Beauvais in the Oise).          '

PROVENANCE:

1.  compare to small pitchers and bowls, uncovered in the excavation of the
school (Fouilles de l'Ecole) at the town La Chapelle-aux-Pots (a town origi-
nally known as La Chapelle-en-Braye near Savignies).  These pots are dated
at the beginning of the XVe century, and there is a major collection of them
displayed in the Musee Departemental de l'Oise.  See Ceremiques du Beauvaisis
by Jean Cartier, 1984, pp. 217ff (ill.).  [I will try to send you a xerox
of the similar pots].

2.  Paris, Art Domestique Ancien - a dealer in ancient, including medieval,
cooking wear, household vessels, and pottery.

The Beauvaisis is one of the centers of stoneware production in medieval
France.  It is said that these tiny ink pots (according to the dealer from
whom they come) were made by apprentice potters, a theory which is not out
of line with their similarity with the larger pítchers made in the same
region.