Amazingly comprehensive book -- if you're a woodworker. He has a whole section of electron microscope pictures of the results of different sharpening techniques, and goes through just about every woodworking tool that has ever existed, talking about how each is used and how sharpening it should be approached. He talks about the difference between oilstones and waterstones, micro-bevels, sharpening fixtures, wet and dry grinding, how to regrind screwdrivers so they work right, how to set up competition two-man saws: it's amazing. He's also a funny writer, not in the jokey way but in clever, wry asides about how things go wrong and why he believes things, sometimes in the face of all evidence to the contrary.