content: Simple drawings, accompany simple mechanisms. This is a great book for learning basic mechanical princibles. There is not alotof theory and formula. This is a excellent introduction to building automata. I use this book in my kinetic sculpture classes and it works well. My only critique is that the oneelectronic diagram is confusing and, well not drawn in a correct manner. But hey! This is not an electronics book. A great addition to the kinetic sculptors library.