I remember it was in the new books section of the school library and I was attracted to it immediately and spent the day reading it instead of paying attention in my classes. I need to read it again. Thanks for bringing it up!
I read that ages ago. Back in high school, in fact (I'm 46). I don't remember it except the chapter where time is a flock of birds that you have to try to catch to stay youthful. The children can catch them but always let them go and the adults can never catch them.
Wheeled carts are not very practical without draught animals to pull them. And the one place they had animals like that, in South America, llamas and the civilizations that utilized them lived in the mountains where wheeled carts aren't practical either.
Pff. You call that flying?