Among the most valuable attributes of this book are the maps, line-drawings, and a fascinating collection of old photographs. Many of these last show clearly the importance of the water wheel in areas where the use of steam was uneconomic. But the author's practice of translating Welsh place-names in the text is distracting; such translations would be better placed in an appendix.

Industrial archaeological is still in its infancy and much remains to be done if we are to preserve available records of past industries. Land use is now changing rapidly and much of this preservation will depend on the enthusiastic amateur, especially the skilled photographer. Mr. Rees's book will prove a valuable guide to such people. It will also be of great assistance to those who are involved in the teaching of local studies in our schools.