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. "M. Antistius Euporus" by Paolo Albéri Auber The author tells again about the Plintio Lacunare in Aquileia (UD) exposing the results of new studies and researches on the subject. 2. "The making of a reflection sundial using Cartesius Mirror or, how to make such a sundial... and live a [gnomonically] happy life" by Riccardo Anselmi The author describes the various stages of construction of a reflexion sundial, personally conducted using the software Cartesius Mirror developed by himself. He reveals different operational details useful in practice to facilitate the work. 3. "Ethiopian sundial" by Francesco Baggio The author describes the construction of a vertical sundial in Ethiopia on the vertical wall of the St. Luke Wolisso Hospital during his stay as a volunteer medical doctor. 4. "Sun ephemeris comparison" by Gianpiero Casalegno The author presents various programs available on the internet, on PCs or smartphones to compute the solar astronomical parameters useful to gnomonists and compares the results with those obtained from authoritative sources, concluding that all of them can be considered satisfactory to gnomonic purposes, at least for general applications. 5. "The graphical research of hour lines through the section of the sphere" by Alessandro Gunella The article refers to similar articles, generally focused on analytical aspects, recently appeared in Gnomonic bulletins. As an alternative to computation it proposes simple solutions involving the representation of the Sphere in an orthographic projection. It shortly relates about the historical origins of the method and about the graphs recurring in several epochs, in treatises and in encyclopaedias. It observes that in the past its utility was mainly didactic, because the operation involves the construction of ellipses suitable for the correctness of the hour lines to be obtained. The operation was onerous and obviously other methods, more convenient in practice, were chosen, while today such obstacles are overcome by CAD programs. 6. "Giovani Caddei's (or Taddei's) sundial" by Frans Maes The origin and the correctness of a horizontal sundial acquired by the author at a low price are discussed. The instrument, which appears to be a bad replica of an unknown seventeenth-century original, is also compared with two similar objects appeared on the market and with a similar but precise tool from the Museum of the History of Science in Florence. One of the issues that remain open is how to read the signature on the dial: Caddei or Taddei? 7. "Gnomonic machines by Ignace - Gaston Pardies" by Elsa Stocco The article presents two solar instruments, useful to draw sundials, that the Jesuit abbot Ignace - Gaston Pardies, French physicist and mathematician, describes in his treatise. After a brief introduction about the author, a description of the instruments and their reconstruction with the use of the solid modeler Solidworks follow. 8. "Sundials in Geneva" by Francis Tamarit The article shows a sequence of some sundials designed by René Beguin mechanical engineer , inventor, restorer of clocks and gnomonist in Geneva. More in detail the list includes different analemmatic sundials for schools, many vertical sundials, one horizontal and one in a darkroom. 9. "Analemma drawing by Giovanni Monsignori" by Angelo Urfalino and Carmelo Urfalino By drawing in longitude the "line in planitia " of the analemma according to the reference system of the ancient Egyptian cartographers, it can be proved the consistency of the text of the ninth book of De Architectura with respect to the arrangement of tropical diameters as indicated in Vitruvius drawing: summer tropic at the bottom, winter tropic at the top. Therefore, in our opinion, not the Vitruvian text should be amended, as it has been done until now by the classical exegesis, but Monsignori drawing. It's worth noting that article n. 2 by Riccardo Anselmi is published both in Italian as well as in English. A digital bonus can also be downloaded for additional reference material, including the English translation of article n. 4 "Sun ephemeris comparison". Hope you will enjoy the reading. Ciao. Gian
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