This is an excellent textbook on sundials. Starting from a simple clarification of the theory of sundials, describing the motion of the earth around the sun (a bit more than it just goes round) demonstrated by excellent graphics. The book gives a written history of sundials with many photographs of sundials of all types. If you are slightly fearful of the mathematics of dialling this book goes a long way to remove any discomfort by its excellent diagrams. If you want to design your own sundial this is a very good book. If you want to test your knowledge there is a testing section. Francophobes may be alarmed by the fact that there are many references to locations in France (strange from a French author!)but there are easy explanations to translocate your designs to your own part of the world - even describing the functioning of dials north and south of the equator.
Many books on sundials are either trivial (written for primary school youngsters)or heavy going (some of the classic books on the subject).This book is educational, scientific, and easy on the eye. An easy read - and thanks to the author.