diameter: 2.0 cm x h: 5.7 cm
This is an Albertson gravitating stopper is glass with a flared knob at the end. There are two chips out of the glass shank. There are words on the side of the shank that read, "PATENTED // AUG. 26, 1862 // OCT. 11, 1864 // APRIL. 15, 1873"
The gravitating stopper was patented on October 11, 1864 by Albert Albertson and assigned to John Matthews, an associate of Albertson's, in 1866. This closure was apparently first put into use in 1867 or 1868 (Riley 1958). It consists of an elongated glass plug with a flared knob on one end. A rubber gasket was placed on the upper end of the knob which when placed in the bottle sealed the contents by pressing against the inside surface of the bottle at the juncture of the neck and shoulder. The bottle was "...filled in an upright position, then inverted so the stopper would gravitate into closed position, and be held there by the inside pressure when the bottle was removed (from the filling machine)." The Matthew's Patent noted that the stopper could be made of "...glass, hardwood, or other suitable material..." though it is likely that glass was by far the most commonly used material (Bender 1986). (from https://sha.org/bottle/closures.htm#Glass)
