Mark Twain is narrator and the main character in the story. As such, he is also the key to other characters; it is through him that we meet new people and form opinions about them. He is thirty-two at the time he starts the voyage. Throughout the story Twain shows his clever wit in describing situations. With it, he manages to poke fun at most everything that happens.
Jack is another character in the adventure. He is young man with "a head full of good sense, and a pair of legs that were a wonder to look upon." (35) A contribution he makes to the story is his journal, which he keeps diligently at first. Twain tells Jack a finished journal is worth a lot of money, and Jack eagerly listens. However, Jack soon finds it to be a tedious and boring task, and realizes the meaning of Twain's words.
A third character in the book is the doctor, a person that accompanied Twain in his exploration of Europe. The doctor has a calm demeanor, and is slow to anger. Like Twain, the doctor also has a sarcastic wit, which he cleverly employs. The doctor's personality can be seen clearly when he and Twain are being carried against their will on a shopping spree by a Parisian tour guide. In the scene, the doctor uses his sarcasm to goad the tour guide into doing what he wants, while remaining calm at the same time.
An underlying theme to this book is the observation that people tend to jump to conclusions about an unknown. Often, people will be overzealous toward a popular, novel idea. The voyage Twain...