Reading many of the reviews before purchasing this, it seemed like people were a little confused with how to take it.  Admittedly, I was kind of puzzled by the book once I got it as well, until I finally figured out what this book really is.<br><br>This book is a puzzle book. As someone who is mechanically inclined, this book gives you tons and tons of these mechanical drawings (with little or no interpretation) and it's then an exercise to mentally rotate the image and visualize how the mechanisms interact with each other.  This is the book of crossword puzzles for those of us who hate crosswords and love to work with our hands and build stuff.