OK, this may not be the most exciting book in the world, and it's hard at first to find your way around, due to the unique Victorian way it's arranged.
But it's worth the effort, as this arrangement means that you can find all sorts of alternatives that a normal A-Z thesaurus wouldn't provide you with. It's very useful, and also just fun. Some of the synonyms it provides seem a little unconnected, but that's half the fun, and if you read through the entire entry for one word, you can end up in a completely different place.
All in all, a great investment for anyone who loves words.