Nore, mutiny at, [234-235]
North Sea Mine Barrage, see Mine Barrage
Octavius, Roman emperor, at Actium, [61-69]
Ontario, campaign on Lake, [283]
Open Door Policy, [330], [447]
Oquendo, Spanish naval officer, [157]
Ordnance, early types of, [94]; introduced on ships, [146]; at Armada, [150]; breech-loading, [289]; rifled, [289]; long range, [374]
Oregon, U. S. battleship, cruise of, [314], [315]; at Santiago, [326], [327]
P.