I hope you are enjoying this book. It is one of my favorites! Now, let's look at a few examples of the figurative language you need help with.
In Chapter III, the red carpet that is to be rolled out for Professor Sherman is "rolled up like a huge jellyroll" (35). This is a simile because the carpet is being described as "like" something it is not. Obviously, a carpet is not a jellyroll, but this simile gives us a picture that allows us to see what the carpet looks like when it is rolled up.
An example of a metaphor in Chapter V is in Mr. F's explanation to Professor Sherman about the effect of taking diamonds off the island. He tells Professor Sherman that this would "cause the diamond market to crash" (74). Now, a diamond market is a financial market that cannot literally "crash." So this is a metaphor which explains something abstract in terms of something concrete. We can "see" a crash.
An example of personification may be found in Chapter V, when Professor Sherman is walking with Mr. F. There is volcanic activity on Krakatoa, and Mr. F. is explaining this to Professor Sherman. He tells his audience that the earth begins to shake, "as though this explanation had been a cue for the mountain to perform" (66). This is personification because the mountain is being described as doing something a person would do, performing, but of course, a mountain cannot perform.
There are many other examples of each literary device in these chapters. See if you can find some, too. Good luck!