Northwood Glass Company

This underlined "N" in a circle mark is the most prolific in classic Carnival glass. Most pieces with this mark are old carnival pieces, but it's wise to remember that Wright reissued several patterns (Grape and Cable butter dish and Grape Delight nut bowl are the most frequently found) with the mark after they bought the molds. They were later forced to change the mark making the later reissues less of a problem for collectors to identify. Reference: www.ddoty.com