Battye grenade

Simple hand grenade issued to British troops in 1915. It consisted of a cast-iron cylinder with an open end, filled with ammonia and closed with a wooden plug. A hole bored through the plug allowed the insertion of a length of time fuse and a detonator. At the outer end of the time fuse was a percussion cap which, when struck, ignited the fuse to give a delay of about four seconds before the grenade exploded.