Fabulous flint glass master salt cellar in the Collared Bulls Eye pattern c. 1840. Shown as #29 on page 28 of Much More Early American Pattern Glass by Metz.
It is 3 1/8 inches across and 2 1/4 inches tall. It is in good condition with no chips, cracks or stains. There are some shallow depressions on the rim. They are either just an unevenness that occured in the making, or very, very old flakes that look and feel fire-polished.