The 21 Balloons

Twenty of the 21 balloons mentioned in the novel’s title—the 21st is Sherman’s own balloon, the Globe, with its basket-house gondola—are attached to a wide platform made of light wood. The balloons, folded and ready for use, are attached to hoses connected to large cylinders of compressed hydrogen. During the escape, these cylinders are opened, and the gas quickly fills the balloons, which lift the platform and its passengers away from the exploding island. This life raft is the single concession the islanders make to the fact that their wonderful life on Krakatoa can come to an abrupt end. Despite the romance and danger of the island, its residents show a practical side that ultimately saves them.

The children’s Balloon Merry-Go-Round is a contraption made of boats attached to each other in a circle around a central pole. The boats, lifted by balloons, swirl around the pole, higher and higher, until the entire wheel of boats soars off into the sky. Eventually, the children deflate the balloons and land in the sea, where they raise sails and race back to the island. The whimsical merry-go-round serves as a device that demonstrates the resourceful ingenuity of the island’s children and their ability to cooperate in an orderly manner to enhance their enjoyment of island life. It also permits the author to foreshadow the coming disaster on the island, as Sherman describes the dark and frightening cauldron of smoky lava that will soon threaten the islanders.

Krakatoa contains caves filled with diamonds—giant boulders made of the glittery stuff, as well as smaller stones and pebbles. The caves ensure a lifetime of wealth to whomever finds it, but only if they dispense those riches carefully. The Krakatoans at first fight over control of the mine; eventually, they realize there is more than enough wealth to go around. They live under a promise never to reveal the mine to outsiders, lest a wholesale invasion ruin the island and reduce the value of diamonds to pennies.

The diamonds serve as a warning that vast wealth must be curated carefully and shared with others. The mine can be seen as an allegory about a world made suddenly wealthy by the “discovery” of the modern era’s new technologies, which bring riches but can disrupt societies. The Krakatoans’ management and equitable distribution of their wealth presents an alternative to the “zero sum game” approach that divides people into economic winners and losers.

Sherman names his balloon the Globe: Its purpose is to take him on a trip around the globe. He declares that it’s the second-largest balloon ever built. It serves its purpose nicely for a week, until seagulls tear it open, and Sherman must crash-land on Krakatoa. Hanging below it is a tiny “basket house,” built of light materials, which contains the minimum comforts and a lot of food. Anticipating his year-long traveling needs, the professor designs both balloon and house carefully. He adds ingenious touches, including the use of metal plates and cups instead of china, a veranda around the house for easy sightseeing, an inflatable bed, and a system of raising his altitude by tossing garbage overboard.

The craft symbolizes Sherman’s knack for inventive practicality, a trait that helps him succeed in his remarkable adventure. It also is meant to inspire readers, especially young ones, with the idea that enthusiasm, coupled with smart thinking, can achieve almost anything a person desires.

The island where Sherman crash-lands is a real place that blew up in 1883 in one of the most famous volcanic catastrophes in history. The author chooses this site for several reasons. Few people would dare to live on so dangerous an outcrop, which makes it a perfect hiding place for an undiscovered, fictional civilization in a world already thoroughly explored. Volcanoes and diamonds are linked geologically, which makes for a convenient source of the islanders’ stupendous wealth. The idea that the ground rolls like waves also adds a unique thrill to the story. Finally, it’s interesting to speculate on what this exotically dangerous island might have been like in the years before it exploded. (For more on Krakatoa, see the Background section “Historical & Scientific Context: Krakatoa Volcanic Activity.”)

The Krakatoans build an escape platform to be used in case the island becomes violently unlivable. It’s a large, flat surface with a railing, plus 20 folded balloons attached to hoses and ready to be inflated at a moment’s notice. This craft, ingeniously designed, serves its purpose at story’s end, when Krakatoa explodes. The escape craft answers Sherman’s concern that the Krakatoans live a life that’s unrealistic and dangerously romantic. It also reminds readers that nothing lasts forever, and that it’s always wise not to be too attached to one’s lifestyle but instead be prepared to move on, should things change abruptly.