harness of breeching and strong side-tackles—the devices that anchor back and sides of cannons to prevent them from jolting out of position.
long rammers and shorter instocks—tools for loading and firing cannons.
tampioned—stoppered (when not in use).
the minister of Christ though receiving his stipend from Mars—Melville is emphasizing a paradox: the chaplain’s service to a god of peace is salaried by the War Department.
living trophies . . . in the Roman triumph of Germanicus—Ancient Romans during the time of Germanicus Caesar (15 B.C.–19 A.D.) celebrated wartime victory with a period of thanksgiving marked by a triumphal procession of captured weapons, horses, and human hostages, especially nobles and their children.
the Pope of that time—Gregory the Great (c. 540–604).
Fra Angelico’s seraphs—angels painted by Giovanni da Fiesole (1387–1455), known as “Fra Angelico,” or the angelic friar.
plucking apples in gardens of the Hesperides—The Hesperides were nymphs of early Greek mythology who guarded a grove of trees bearing sacred golden apples.
