"His lively pen, his direct and simple style, his expressive vocabulary, his avoidance of pedantry, his conciseness in the exposition of his thoughts make his book a pleasure to read." — Henri Michel, International Academy of the History of Science The story of man's efforts to measure time is a long one — reaching back thousands of years to the dawn of civilization. Among the earliest instruments developed for telling time was the sundial. In this expert study, a noted sundial expert offers a fascinating and informative account of these ancient devices, presented in simple, lively language. Over the centuries, many different varieties of sundials have been constructed, and Mr. Rohr provides detailed, accurate descriptions of them all: classical sundials, inclined dials, solar calendars, analemmatic dials, moon dials, and many more. There is even a chapter devoted to especially remarkable dials past and present, and a listing of the most popular sundial mottoes. In this profusely illustrated volume, you will not only learn about the long and colorful history of the sundial, you will learn a practical method of building one yourself. No special knowledge is required, other than an understanding of the basic principles of cosmography and of the relative movements of the sun and the planets. (These are recalled in an elementary way in a special chapter.) For mathematically inclined readers, more complex formulae and calculations have been included, some of which have never been printed in a book of gnomonics.