The combination of the "AC" monogram, the bee, the "FIREPROOF" designation, and "MADE IN SAXONY" strongly indicates that this is a glass product made by A. C. Cosens & Co. (or possibly A. C. & Co.) They were known distributors and possibly makers of lamp chimneys and globes, which were often manufactured in Germany (Saxony) in the late 19th and early 20th century.
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