In order to cram that many mechanical bits into so few pages, the illustrations are frequently small, but intensely detailed. You'll find several of them on each page. This is great reference material for steampunk, sci-fi, and fantasy artwork, but since each device has only one illustration, it would be next to useless as a technical manual. There is a huge array of different devices - from tiny gears to giant steamworks - so as long as you're browsing for inspiration, this is a great book to have on hand.