This antique aqua blue glass "beehive" insulator was made by the Brookfield Glass Company likely in the early 1900's based on it's mark of a single "B". The top inside is also marked "2", denoting the shop in which is was made.
It measures 4 1/4" high, 3 1/4" wide, and weighs 1 pound, 8 ounces. It is in fair vintage condition (good condition for its 140+ year age), with a few chips on the inside edges, and fissures and bubbles inside the glass that may have been manufacturing anomalies. There are no cracks that reach to the outside that I could see. Please see all photos for condition details.
Insulators were originally used on telegraph, telephone and railroad lines. But now they are a colorful piece of communications history that can make unique windowsill or mantle decorations, as well as paper weights! Or turn them upside down inside a flat base and use them as candle stick holders.