Preponderance
This specified the amount by which the breech end of a gun mounted on trunnions was heavier than the muzzle end. This was determined by the location of the trunnions, the lugs on the barrel by which it rotated in its mounting, which were usually located slightly forward of the gun's centre of gravity. E.g. if the preponderance was quoted as 4 tons 2½ cwt as for the RML 17.72 inch "100-ton" gun, the breech end sat with that weight on its mounting, enough to ensure stability but not enough to hinder changes in elevation. The preponderance of British muzzle-loading guns was typically stamped on the end of one of the trunnions. The term was dropped when it became meaningless with the replacement of trunnions by more modern methods of mounting guns on recoil slides in the 20th century.
Read more about this topic: List Of British Ordnance Terms