The most unusual feature of this collectible Birdseye lamp is the unusual vacuum tube shaped glass envelope, rightly fitting for advertising RCA products during the 1930s! A vintage article has surfaced that provides more information about this lamp21:
Novel “Neon” Bulb Can Also Be Used As Night Sign
For scarcely more than the price of an ordinary lamp, dealers can now get a novel display piece that has great attention getting value. The letters “RCA” inside the bulb shown here have a “neon” glow when the bulb is screwed into either an A-C or D-C 110-volt outlet. The price of the RCA Glow Tube is only 60˘ It can be obtained from RCA Radiotron distributors
For Windows or Interiors
Many uses for the Glow Tube will suggest themselves to stores that realize the effect of novelty in window or interior displays. Several of the tubes might be screwed into sockets to outline a window, or with a little ingenuity special display pieces can be rigged up using the tube. In the store, one or more tubes could well be used to mark the RCA Tube department.