This is an original 20th-century galvanized ship's masthead navigation lantern, manufactured by C.M. Hammar in Göteborg (Gothenburg), Sweden. It is in good used condition with a patina corresponding to its age. It has not been restored. The lantern is 50cm tall (not counting the height of the carrying loop) and 26cm wide. It is quite heavy, weighing in at 6.7kg. The lantern features a thick Fresnel glass lens, designed to project a horizontal beam of light over long distances. The internal oil burner is original, with the original fount (fuel vessel), and burner assembly, including the wick and lamp glass. The wick turner dial is well preserved and features an anchor overlaid with an arrow pointing clockwise. This is the historical logo for CM Hammar, indicating that the burner assembly is entirely original to the Goteborg housing. The anchor symbol indicates that the burner was manufactured specifically for sea-faring conditions and nautical navigation lights. The arrow indicates the direction in which to rotate the wheel to raise the cotton wick. The lantern was manufactured between the early 1900s and the 1940s, with the exact manufacturing date not known, but likely around the 1930s due to the blocky lettering of the logo and the use of metal brackets to secure the large Fresnel lens. The CM Hammar factory built these lanterns to withstand severe North Sea conditions. The lantern can be picked up in the Netherlands, or shipped if required.