"The way we work" (the other book by same David Macaulay ;)). DC has read both cover to cover and still comes back to both. (Re. age-appropriateness: there is one illustration on reproduction at the end of the book which you might want to check.)
Unfortunately, I do not know any other books in this category which come even close to these two in quality. I'll try the one you recommended ("QAE").
Arlen1
DS LOVED that book - all Maccauley actually - but we actually cut that page out of the book - we can't understand how he has never noticed it! But it was just so graphic and explicit and he was 5 when we got him the book. But the science is great!
I have recommended in 10000 threads, the brainwaves books, great science, lots of pictures and facts. DS adored them.
DeHe