1. Bars used to support the glazing and the roof of a lantern.
2. In the U.S.A., loosely used for bars supporting the optical elements of a prismatic lens or of a fixed lens. (Fig. 16b)
Note 1: In Britain, the term is used in sense 2 only in respect of a fixed lens.
Note 2: The German term Verstrebungen is also used for bars supporting the optical elements of a prismatic lens or of a fixed lens.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM