Reseña del libro "sundials: their construction and use"
To many people, the construction of a sundial implies laborious mathematical calculations and a knowledge of astronomy. Nothing could be farther from the truth. This fascinating handbook, used in conjunction with ordinary tools and materials found around the home, makes it easy to design and construct a sundial on almost any surface and in virtually any position. Introductory chapters offer a wealth of information on the sundial's development from ancient times to the present, why the sundial tells time, how to design and make a dial, and more. These chapters are followed by full instructions on how to construct the hour lines for many kinds of sundials, by the graphic or geometric method. The use of this method doesn't require a knowledge of mathematics or astronomy. It simplicity and accuracy, together with the ease and quickness of delineation, make it very practical. Readers will also find fascinating chapters on dial furniture, portable sundials, constructing a heliochronometer (a highly precise solar timekeeper), sundial classification, and other topics. Accompanying the text are 150 well-chosen illustrations, many published for the first time. They depict scale models, as well as a moon dial, a cathedral dial, and other actual dials from around the world, including the world's largest, in Jaipur, India. If you've ever wanted to build your own sundial, or if you simply want to know more about these ancient timepieces that can show the time of day as accurately as many clocks, this clearly written, easy-to-follow guide is the best book available. -- Commonweal.
