The initial letter, Walton, tells his younger sister about his preparations that led to his departure to the north of the pole. The desire that he had on accomplishing the purpose helps him in the discovery of the way to pacific; this led to revealing of the Margaret in the earth.
The novel, therefore, has several letters, Walton is an Englishman who has a seafaring passion as the ship captain while to the dangerous voyage that reveal the sources of the earth’s magnet.