Historical information

A porthole, sometimes called bull's-eye window or bull's-eye, is a generally circular window used on the hull of ships to admit light and air. Though the term is of maritime origin, it is also used to describe round windows on armoured vehicles and aircraft.

On a 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 porthole is an example of a ships fittings and is not associated with an historical event, person or place, provenance is unable to be determined at this time and the item is believed to have been made in the first half of the 20th century.

Physical description

Porthole and cover, brass and glass with 1 screw dog to secure hinged cover.

Inscriptions & markings

Marked 6" on ring