antique early 1900s vintage replacement shade for pendant light, opalescent white glass

Old translucent opalescent white glass shade, early 1900s, made for an early electric pendant light fixture for schoolhouse or other industrial / commercial use. This is original architectural salvage, not a new reproduction.

The shade measures 11" wide across the opening, and 2 1/4" across the fitter. It's very heavy, beautifully made (though there is a little edge roughness, from manufacture or use).