Original Polyphone catalog circa 1900 showing pictures and prices for their attachments. The Polyphone Company of Chicago (operating under The Talking Machine Company and variations like the Chicago Talking Machine Co.) was a prominent turn-of-the-century audio pioneer best known for marketing the Polyphone attachment. Patented in November 1898 by Leon Douglass—who later became the president of the Victor Talking Machine Company—and sold alongside co-founder Henry Babson, the Polyphone was one of the most unusual and sought-after inventions in early phonograph history. It was endorsed by Edison for use on his machines. The only thing rarer than a Polyphone attachment is this catalog. Measures 4" tall and 3" wide. In overall good condition with paper loss to the last 2 pages. See photos. From the Allen Koenigsberg collection.