Dear friends, a new issue of the Italian magazine Orologi Solari is available for download from the usual site http://www.orologisolari.eu/.
Here is the list of articles together with a short abstract: 1. "Paralipomeni of the "daylight triangle" on horizontal sundials" by Albéri Auber Paolo After the Gnomonic National Seminar held in Chatillon in October 2012, the author was correctly urged by Alessandro Gunella to elaborate (Paralipomeni) on what is written in the records. The subject of the daylight triangle and more generally of the estimate of the duration of the day in different seasons is thus resumed. 2. "The daylight triangle and its use" by Albéri Auber Paolo and Caviglia Francesco The article explains what the daylight triangle, little-known to today's gnomonists, is and how it must be used to deduce the length of the day in different seasons. In particular, the problem of how to use the triangle in an ancient (or temporal) sundial is addressed; actually, the operation is not immediate in this case and it requires some calculation. 3. "Bifilar sundials with Photoshop" by Caviglia Francesco and Nicelli Alberto A fundamental property of bifilar sundials on flat surfaces with rectilinear wires parallel to the dial is recalled: to be simply achievable by scaling one of the cartesian coordinates of a gnomonic point sundial drawn on the same dial. How this transformation can be done using an image processing program is explained and formulas to obtain it through calculation are reported. 4. "Equatorial sundial" by Coco Nicola The construction and operation of a simple equatorial sundial, elegant and instructive, is described. A brief reminder of the French gnomonist Robert Sagot, who proposed this sundial model in a short paper, is reported in the Appendix. 5. "Personal considerations on the gnomonic history (2nd part)" by Gunella Alessandro The article is the author personal excursus into the part of the gnomonic history limited to Europe and to Mediterranean. A stimulus for those who may want to complete it in any deficient or missing parts. 6. "Matelica & Prosymna: the point of view of one who makes use of graphical methods only" by Gunella Alessandro Following the recent articles concerning the Sphere of Prosymna, published in "The Compendium" and in this magazine, the author, having resumed part of his discussion on the Matelica sphere already published in 1999 in the UAI magazine "Gnomonica Italiana", analyzes by means of graphical methods only the traces marked on the Prosymna globe. 7. "Transparency sundial with trifocal lens gnomon" by Cesare Lucarini and Mario Catamo On a glass window at the University of Rome "La Sapienza", the authors have built a transparency sundial with a trifocal lens gnomon. The construction process is illustrated, from calculation to drawing, glass engraving, decoration and assembly. Special attention is given to the description of the gnomon, consisting of a trifocal lens that focuses the light spot, greatly enhancing the vision by transparency, inadequate with traditional methods because of the large dimensions of the sundial. The time shown is the TMEC noon. 8. "Reflection sundials" by Savoie Denis Formulas for the calculation of reflection sundials, where both mirror and dial have a generic orientation, are reported. 9. "An unusual horizontal height sundial" by Denis Savoie and Joseph Theubet The unusual horizontal height sundial installed in front of the Museum of the History of Science in Geneva is discussed. The instrument dial is drawn on a rotating disk, to be oriented according to the date and to the direction of the Sun. 10. "Return from the past" by Stocco Elsa The author describes the recovery phases of an ancient Italic sundial on the block of a historic Trevigiano farm: a teamwork that combined techniques of conservative restoration with those of gnomonic computation. On the ancient plaster, which has regained the material finesse, the original appearance and vibrations, the ancient sundial returns to live and to mark time, symbol of a place connected to the culture of earth and nature and therefore unavoidably to Sun and heaven. A digital bonus can also be downloaded for additional reference material. Hope you will enjoy the reading, although in Italian only. Ciao. Gian
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
