be back and to give the speech to the densely packed audience in the auditorium of the Western American Explorers' Club in San Francisco. However, all in all, he is still eager by the end of the book to have his year-long vacation away from people.

In Chapter 4, the reason why Professor Sherman crash-lands on Krakatoa is because seagulls harmed his balloon. As soon as he saw the seagulls, he immediately fed them his garbage, but he was unable to anticipate that they would fish the garbage from the ocean then fly back up to the top of his balloon to have their feast. Since he hadn't thought to bring a hunting riffle, he had no way to protect himself and his balloon from the gulls. Two gulls got into a fight on the top of his balloon over his turkey carcass, resulting in the gulls popping a hole in his balloon and one even getting trapped inside. Since there was no way Professor Sherman could mend the balloon while in the air, he had no choice but to land on the island below, which turned out to be Krakatoa.

Landing on Krakatoa happened to be an excellent experience for the development of his scientific mind because it gave him a chance to see all of the mechanical inventions the people of Krakatoa have developed. By the end of the novel, Professor Sherman has advanced scientifically enough that he is able to think of a solution for his next trip: he will invent a "seagull catcher" to attach to his balloon.

Yet, in one respect, Professor Sherman still has not changed by the end of the novel. Though he has come to appreciate people enough that he can be friendly, he is still very eager to get away from people for a full year,  as we see in his final sentence of the book:

I plan to spend one full year in the air, one year of truly delightful living, a year in a balloon! (p. 180)

Professor Sherman names his balloon "The Globe." This is entirely appropriate given its projected size, as well as the nature of the journey on which he's about to embark. The professor wants to be alone on his voyage, floating high above the earth out of everyone's reach. He also wants to make sure that he stays in the air for as long as possible. This means that he's going to have to build a large balloon, with all the practical engineering problems that that entails.

But there's a precedent. The great French balloonist Giffard constructed a giant balloon of his own, the Clou, the biggest balloon ever built. This remarkable feat of aeronautical engineering consisted of no fewer than seven alternating thicknesses of rubber and silk. Professor Sherman's "Globe" has four alternating thicknesses of rubber and silk and is six thousand cubic yards in size—ten times the size of a normal balloon—making it one of the largest balloons ever made.