Papers to be presented at the NASS conference in Tucson. Friday and Sunday morning will be dedicated to talks and displays on dialing. The schedule is still open and we have room for additional speakers. Please contact Fred Sawyer if you would like to deliver a talk - or if you would like to do a shorter, 10 minute presentation on some aspect of dialing.
Speakers currently scheduled include: Roger Bailey / Mike DeAmicis-Roberts Seasonal Sunrise Marker There is a point on the east/west axis of analemmatic sundials that can be used with the date table on the north/south axis to show where and when the sun rises or sets. The presentation outlines the discovery of this idea, the theory and calculations to determine the points, the construction of the first seasonal dial using these markers, and techniques to improve the accuracy to compensate for periodic error and horizon pollution. Harold Brandmaier Latitude Effects on Sundial Design My interest in sundial design using matrices led to a study of latitude effects. The results are presented in a series of dial-face layouts for a number of common sundials. Included are inclining and declining sundials and those which both incline and decline; horizontal and vertical azimuthal sundials, and altitude dials. Finally, alternate approaches to showing day-lines are briefly discussed. Tom Kreyche Projections of the Sphere for the Planispheric Astrolabe and Double Horizontal Dial This talk uses strict cartographic descriptions to present a general background on projections, and an in-depth discussion of those used for the planispheric astrolabe and double horizontal sundial. This talk also includes a discussion of computer-based design techniques. Stephen Luecking Constructing Daylines This talk introduces the point-wise construction of hyperbolas and its application to daylines. During the Renaissance, artist/scientists such as Leonardo Da Vinci, Albrecht Dürer and Piero Della Francesca began experimenting with methods for constructing these curves. Their experiments and those of others led to the point-wise construction of conic curves, a method which was to presage the plotting of curves in analytic geometry. Fred Sawyer Dialing and Cartography I An examination of several of the threads linking the history of dialing and cartography together. Fred Sawyer Dialing and Cartography II Introducing a new family of compressed gnomonic sundials, deriving from an early 20th century map projection. Fred Sawyer A Mandl Abac Sundial Showing the development of a new universal altitude sundial from a simple nomogram by J. Mandl. Sara Schechner Savvy Travelers How time finding tools served those on the move in the Renaissance. A look at pocket sundials and astronomical compendia, with their remarkable components (including gazetteers, specialized hour scales, astrolabes, quadrants, nocturnals, maps, and travel guides). John Schilke Oh, East is East and West is West..A Note On The Prime Vertical The prime vertical is that great circle which passes through the zenith and nadir and the east and west points of the horizon. It has a few properties which make it useful for the dialist. We present two methods of establishing the PV as well as examples of dials for which a readily determined local east-west line is even more convenient than the meridian. -
