A Princess of Mars
Burroughs introduced "A Princess of Mars", the first Barsoom Novel as though it were a factual account passed on to him personally. He imagines John Carter to be an avuncular figure known to his family for years who entrusted the manuscript of the novel to Burroughs for publication 21 years later. The Gods of Mars is the second Barsoom novel to use this device. John Carter 'visits' Burroughs 12 years after the events of "A Princess of Mars", claiming to have mastered the secret of inter-planetary travel and stating this will be the last time he makes such a journey from his adopted home. However, the device was used in two further Barsoom novels, "The Chessmen of Mars" and "Swords of Mars".