I got this book from the library by recommendation from this website. I'd give it 3-4 stars. My 10 year old really liked this book and found it interesting. My 8 year old, however, thought it was "just fine." She didn't love it; not sure that she was interested enough to even read all of the words. I did read all of the words but I understand her opinion. I liked how the story tells of the brothers having to try and try again to achieve their goal. A quote from the book by one of the brothers: "If just one experiment out of a thousand succeeds, then you're ahead of the game." That is, indeed, a positive message that our children could benefit from learning. I also really liked the simple yet colorful pictures.