Quotes that prove piggy is intelligent in Lord of the Flies?

I need to quotes (plus pages if you can) that shows that Piggy is smart. I've been searching through the novel and don't remember any specific moments of intelligence!



Piggy, for all his ludicrous body, had brains. Ralph was a specialist in thought now, and could recognize thought in another." Chapter 5, pg. 71

Find the bit where Piggy starts talking about the sundials, where he attacks the notion of there being ghosts where the boys are all having meeting.