Knock knock, what was that book?
April 14, 2014 2:18 PM Subscribe
Please help me find a mystery book from my childhood. I am stumped. It would have been in the mid 70s, probably between 1974-77. I think it was science/nature-related book that may have been one of a series. What I remember is a hard-cover book, and on the back inside cover there was mounted a round plastic disk with an arrow inside, sort of like a compass. It was visible though holes in the pages and front cover. There were questions with multiple choices on each page, and you would close the book and knock on the cover a certain number of times to make the needle point to the correct answer on a corresponding page. That sounds crazy even as I type it, but if someone could find this book (or even corroborate my memory) I would be eternally grateful.