Du Bois (Pene du Bois?) does a good bit of world-building, as it might be called now, but then unfortunately doesn’t do anything with it. The whimsical Krakatoa Island he conjures, where twenty families live in harmonious luxury provided by plentiful secret diamond mines, is quite the place. Every day a different family takes turns cooking the meals for everyone. Although they are all originally from San Francisco, each family adopts a culture or country on which they base their housing and cooking style. They even change their names – “Mr. A” for American, “Mr. B” for British, “Mr. C” for Chinese, etc.
Sadly, the narrator is just getting to know the place when Krakatoa erupts, destroying the island. Luckily the families flee (by balloon, of course!) in the nick of time. The families parachute off the balloon contraption in India and Belgium and are never heard from again (well, at least by readers of this story). The narrator, newly arrived in Krakatoa via balloon across the Pacific, crash lands the balloons in the Atlantic, where he is rescued. His story attracts a lot of attention due to his inadvertent around-the-world travel.