Free Astronomy Magazine March-April 2022

45 MARCH-APRIL 2022 ASTRO PUBLISHING T he sundial of the Palais de Justice in Besançon, near Saint-Pierre Square. This sundial is, in fact, a vertical dial that declines in the morning. online also allow one to delve into ancient scriptures by downloading beautiful books from the 17 th or 18 th centuries and discovering geometric methods richly illustrated with hand engravings. While it is possible to manually cal- culate a horizontal or vertical south- ern sundial, it becomes a bit more complicated to accurately trace a vertical descending sundial, or to trace the sidereal hours and analem- mas. Many people dream of mak- ing a sundial on their own for their garden or the facade of their house, expressing their talents in painting, cially in some regions such as the French and Italian Alps. It is one of the rare subjects that combine sci- ence with art or handicraft, as well as with philosophy, with inscribed mottos that often make passersby reflect on their life and the passage of time. Many books on the subject have been published in the last thirty years, including technical and math- ematical, as well as beautiful pho- tographic books that allow, for ex- ample, the reader to discover the many sundials of Queyras or the Hautes Alpes. The archives available sundials. The Louvre Museum and the National Conservatory of Arts and Crafts in Paris, the Galileo Mu- seum in Florence, the Navy Museum in Madrid, the Adler Planetarium in Chicago, the Greenwich Observatory in England, the Munich Science Mu- seum in Germany… Each time, these collections amaze and arouse inter- est and admiration. Disappearing into oblivion for a while starting in the nineteenth cen- tury due to the spread of mechanical wall and wrist clocks, sundials re- turned to fascinate the public, thanks in no small part to software and computerized drawing and carving tools. More and more people are in- stalling one at their houses, espe-