Mechanical watch vintage ship wall clock! Features a frame with metal dial and glass window. Hangs via 3 screw holes at the base. A porthole, sometimes called bull's-eye window or bull's-eye, is a generally circular window used on the hull of ship. The function of a porthole, when open, is to permit light and fresh air to enter the dark and often damp below-deck quarters of the vessel. It also affords below-deck occupants a limited view to the outside world. When closed, the porthole provides a strong water-tight, weather-tight and sometimes light-tight barrier. The clockwork is clean, oiled and runs very exactly.