quarterdeck vs turret

quarterdeck

noun
  • The aft part of the upper deck of a ship; normally reserved for officers 

turret

noun
  • An armoured, rotating gun installation on a fort, ship, aircraft, or armoured fighting vehicle. 

  • The elevated central portion of the roof of a passenger car, with sides that are pierced for light and ventilation. 

  • A little tower, frequently a merely ornamental structure at one of the corners of a building or castle. 

  • A siege tower; a movable building, of a square form, consisting of ten or even twenty stories and sometimes one hundred and twenty cubits high, usually moved on wheels, and employed in approaching a fortified place, for carrying soldiers, engines, ladders, casting bridges, and other necessaries. 

  • A tower-like solder post on a turret board (a circuit board with posts instead of holes). 

How often have the words quarterdeck and turret occurred in a corpus of books? (source: Google Ngram Viewer )