When I was a boy I loved all his books. The most treasured was this one:
This one is not about predicting the future and contains very few science fiction elements, but it is absolutely great adventure story.
I can't wait until my daughter is big enough to appreciate this story, so I can read it to her from my very old, tattered copy with beautiful woodcut (metalcut?) illustrations. I have inherited this one from my father. It used to be his favorite book ;-)
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All the books you find here