The novel was intended to teach bout family values, good husbandry, the uses of the natural world and self-reliance. Many of the episodes have to do with Christian-oriented moral lessons such as frugality, husbandry, acceptance, cooperation. The adventures are presented as a series of lessons in natural history. The novel opens with the family in the hold of a sailing ship, weathering a great storm. The ship runs aground on a reef, and the family learns the ship's crew has taken to a lifeboat and abandoned them. Subsequent searches for the crew yield no trace.