What you may have noticed is the episodic nature of these short chapters! Like many early science fiction and fantasy novels, this novel was first printed as a serial! A Princess of Mars is actually fairly “joined together” for a serial novel. The next book in the series however is much, much worse, mostly because of the Very Obvious Repetitive Cliffhanger where it takes quite a long time to find out the full name of a young man John meets during his adventures. You will of course know who the young man is before the second cliffhanger cuts off the introduction.