Any book recommendations, for a gifted 8 year old boy, that gives a lot of useful knowledge about a wide variety of topics?

Wow, that made a lot more sense in my head. Let me try that another way...my son loves impressing us with all that he knows (which is a lot more than we typically give him credit for...especially my 19 year old daughter who is in college).

ie: the other night we were discussing spiders and he told us they typically have 8 eyes...the whole family (including me) got a strange look on our faces. Of course we googled it and he was right...asked him how he knew it and he said he didn't know.

So, since he loves gaining and giving knowledge, I'm looking for a book that might interest him and contains a lot of facts from a variety of topics.

Thanks.

TripleB