The Tremlett's Naval Pattern Fighting lamp wa used in gun casemates to illuminate the guns when fired at night. There are no known examples of this lamp left. The one above is a replica, fabricated from drawings researched by the PFS after many years of searching.
The Tremplett's Fighting lamp was hung on a metal bracket fastened to the pier of the casemate on one side of the gun. A fluted reflector inside the lamp allowed adjustment so that light did not give away the gun position to an enemy outside the casemate.