This book provides both an overview of the history of the slide rule, some of its cousins (e.g. circular and cylindrical) and its ancestors, and a reference table of practically all slide rules ever made. The table lists the type, size and scales of all rules, if known. The book also has tables of slide rule makers and patents.
This book is useful if you are interested in collecting slide rules since it attempts to list all rules known. It does not, however, attempt to trace the evolution or variants of specific slide rule models, nor does it contain much information on specific slide rule makers. It it also not a slide rule tutorial, apart from very basic handling.
Even though the book is thus not a full encyclopaedia of slide rules, the overwhelming completeness of the tables alone would give me cause to award it five stars. The historical overview also makes the book an enjoyable reading, and I recommend it with my whole heart.