Character in an iron-clad of Sir John Millais

I am a character in one of the great iron-clads of Sir John Millais, which has been built to resist the shot of enemies, but not to defy the storms of friends. I am a link in the chain of that mighty engine which binds together the plates of the "Warrior." I am one of the thirty-two mighty bars which form a single block of the great forty-ton gun at Woolwich. I am a part of that monster piece of ordnance which has been constructed out of a single block of iron, weighing sixty-four tons, and which has been rendered available for purposes of national defence, by being converted into a machine of war, at the hands of Sir William Armstrong. I am a part of that which has been rendered possible, by being rendered probable, in the shape of