sentences:  The original secondary battery comprised ten 6-inch (152mm) guns, but the overweight condition of these ships forced the elimination of four of these weapons.Intended for prolonged deployments on distant foreign stations, the ships were sheathed with wood and copper to prevent marine growth on the hull, and were originally fitted with a brig sailing rig to economize on coal.After trials showed them to be sluggish under sail, the masts and yards were removed and replaced by a single pole mast between the funnels.