In Chapter 4, Melville goes off on a tangent and discusses how gunpowder was invented and how it revolutionized warfare. He expresses disappointment in the fact that firearms allow people to kill from afar, which he sees as a cowardly way of fighting. He believes that in the past, naval warfare mostly involved close combat with swords or other close-range weapons.

However, even though firearms were used, Lord Nelson, an exceptional sailor, demonstrated courage and composure in combat. Melville admires Nelson's bravery while fighting on the Victory, despite some people criticizing him for showing too much of himself during the battle. These critics also argue that Nelson was reckless at Trafalgar and had he been more careful, he could have survived the fight. If he had lived, Nelson could have possibly avoided the significant loss of life that happened due to a less competent second-in-command.

Despite the criticism of some people, Melville maintains that Nelson was the epitome of a "great sailor," and that his courage was driven by a deep sense of responsibility. Melville points out that Nelson received numerous accolades for his dedicated service to the monarchy.

Lord Nelson, dressed in his full attire and wearing his medals, wrote his final will and testament on the night before the deadly Trafalgar battle. Although some may view Nelson's actions as a display of vanity, Melville sees it as an expression of pride given the circumstances. Melville believes that Nelson's conduct embodied the heroic sentiments expressed by poets in their verses.

A lot of the unhappiness that caused the two rebellions persisted for a long time. Even when Nelson held the position of vice admiral, he was instructed by the admiral to move his authority from the Captain to the Theseus in an effort to regain the crew's loyalty to the British Navy simply by being there.

Even after the mutinies, the complaint about impressment persisted as a major issue. Melville observed that if this practice was abolished, it would severely harm the fleet since there was an unrelenting need for sailors due to the numerous battlefronts.