Free Astronomy Magazine March-April 2022

47 MARCH-APRIL 2022 O n the left, a vertical sundial made by Heiko De Jong with Shadows, for his house in the Netherlands. Below, a painted wood sundial, made by Mark Mills in Springfield (IL, USA), with the same software. the sundial is displayed on the screen and the user only needs to configure it by changing its size and design options, decorating it with clip art or images, and possibly em- bellishing it with a personalized motto, or simply choosing an option from the long list provided by the software. Finally, the result can be printed to scale, possibly on several sheets. For large sundials, the coordinates of the points are provided in Excel-compatible tables. The lines can also be ex- ported in vector format (EMF), to allow one to rework them in Corel Draw or Adobe Illustra- tor, or in DXF format, compati- ble with CAD software and, from there, engraving ma- chines. The computer can help a lot, but the user still has to do the practical work of transferring the layout to the final mate- rial, as well as assembling the stylus and placing it on the facade of the house or on a column in the garden. The satisfaction of the work done will still be there and can be shared with others. The users’ sundials gallery highlights the diversity of layouts and materi- A bove, Italic (green lines) and Babylonian (red lines) hours. Left, sidereal hours. Right, mean time and coloring of diurnal arcs. als. There are horizontal and vertical sundials of any orientation, armillary spheres, portable shepherd sundials, and so on. It is evident how the tal- ent of some can be expressed once the software eliminates the difficulty of the calculations. Furthermore, it is not only the private individual who uses Shadows, but also teachers and professors in their schools for il- lustrating projects on celestial mechanics or the Solar System, and even professionals who produce sundials in engraved stone, wrought iron or fresco. The Shadows software is used all over the world thanks to its