What does Mark Twain mean when he describes the steamboat as being "handsome" in paragraph 3 of "Life on the Mississippi"?

Well, exactly what that word means - he is trying to say that the steamboat is quite a beautiful sight. He is describing the boat as being " long and sharp and trim and pretty," which obviously tells us that he likes what the boat looks like. Twain says that these people are seeing such a boat for the first time in their lives and that they are amazed by it.