A Mutilated Iron Cannon Showing a Protruding Trunnion Near Trunnion Mounts or Cradles.
Naval History Center. Washington Navy Yard.
Washington, D.C.
The makers of bronze cannon also incorporated another major technical innovation by adding trunnions to cannon. Trunnions are cylindrical projections on the side of the cannon barrel that serve as mounts for the gun and as the pivot for changing its elevation.