for vertical declining dials—pen and ruler constructions Sciothericum telescopicum—a sundial invented in the 17th century that used a telescopic sight to determine the time of noon to within 15 seconds. Scottish sundial—the ancient renaissance sundials of Scotland. Shadows—free software for calculating and drawing sundials. Societat Catalana de Gnomònica Tide (time)—divisions of the day on early sundials. Wilanów Palace Sundial, created by Johannes Hevelius in about 1684. Zero shadow day Notes References Citations Sources Reprint of the 1902 book published by Macmillan (New York). Heilbron, J. L. : The sun in the church: cathedrals as solar observatories, Harvard University Press, 2001 . A.P. Herbert, Sundials Old and New, Methuen & Co. Ltd, 1967. Kern, Ralf : Wissenschaftliche Instrumente in ihrer Zeit. Vom 15. – 19. Jahrhundert. Verlag der Buchhandlung Walther König 2010, Hugo Michnik, Theorie einer Bifilar-Sonnenuhr, Astronomishe Nachrichten, 217(5190), pp. 81–90, 1923 Slightly amended reprint of the 1970 translation published by University of Toronto Press (Toronto). The original was published in 1965 under the title Les Cadrans solaires by Gauthier-Villars (Montrouge, France). Savoie, Denis: Sundials, Design, Construction, and Use, Springer, 2009, . Frederick W. Sawyer, Bifilar gnomonics, JBAA (Journal of the British Astronomical association), 88(4):334–351, 1978 Walker, Brown: Make A Sundial, (The Education Group British Sundial Society) Editors Jane Walker and David Brown, British Sundial Society 1991 External links National organisations Asociación Amigos de los Relojes de Sol (AARS) – Spanish Sundial Society British Sundial Society (BSS) – British Sundial Society Commission des Cadrans Solaires de la Société Astronomique de France French Sundial Society Coordinamento Gnomonico Italiano (CGI) – Italian Sundial Society North American Sundial Society (NASS) – North American Sundial Society Societat Catalana de Gnomònica – Catalan Sundial Society De Zonnewijzerkring – Dutch Sundial Society (in English) Zonnewijzerkring Vlaanderen – Flemish Sundial Society Historical "The Book of Remedies from Deficiencies in Setting Up Marble Sundials" is an Arabic manuscript from 1319 about timekeeping and sundials. "Small Treatise on the Calculation of Tables for the Construction of Inclined Sundials" is another Arabic manuscript, from the 16th century, about the mathematical calculations used to create sundials. It was written by Sibt al-Maridini. Vodolazhskaya, L. Analemmatic and Horizontal Sundials of the Bronze Age (Northern Black Sea Coast). Archaeoastronomy and Ancient Technologies 1(1), 2013, 68-88 Reconstruction of ancient Egyptian sundials Other The British Sundial Society including a register of British sundials Register of Scottish Sundials Understanding sundials through map projections The Ancient Vedic