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NASS Convention, 2010 Six New Dials I Would Like to Make, or Like for You to Make, or Like for Us to Make Together. - Bill Gottesman. Wind powered sundial Wheatstone polarizing dial with dipleidoscope Civil time ring (bracelet) dial Vercasson’s Foster Lambert dial Ozanam map dial
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NASS Convention, 2010Six New Dials I Would Like to Make, or Like for You to Make, or Like for Us to Make Together.-Bill Gottesman
Wind powered sundial • Wheatstone polarizing dial with dipleidoscope • Civil time ring (bracelet) dial • Vercasson’s Foster Lambert dial • Ozanam map dial • Hologram dial
A cone whose vertex angle is twice your latitude can be used to make a dial that reads hours from sunrise and hours to sunset. Sundial in Genk, Belgium
Wind powered sundial • Wheatstone polarizing dial with dipleidoscope • Civil time ring (bracelet) dial • Vercasson’s Foster Lambert dial • Ozanam map dial • Hologram dial
Lets build a modern polarizing sundial(adapted from Bradley Schaefer’s polarization sundial article in Sky and Telescope, May 1997) • Camera Lens Polarizer (linear, not circular as for digital cameras) • ½ wave retarder film
In use, the sunlight first passes through the half-wave film, and then the polarizer. “Sandwich” doesn’t work if it is flipped over. Cement film between polarizer and glass window(use clear epoxy or UV optical adhesive)
Retroreflector 90b
Wind powered sundial • Wheatstone polarizing dial with dipleidoscope • Civil time ring (bracelet) dial • Vercasson’s Foster Lambert dial • Ozanam map dial • Hologram dial
Bracelet Dial Images from UK National Maritime Museum website
All read local, not civil, time. • No currently available ring dials are latitude specific. • Scale is confusing • Morning and afternoon hours on same hour line • Dates are typically Zodiacal, if at all. • Takes some dexterity to suspend and read at same time. • But it is a great piece of jewelry! Being specific to location it tells the recipient “only for you.”
(Afternoon example) Altitude 26 degreesWinter Solstice
Wind powered sundial • Wheatstone polarizing dial with dipleidoscope • Civil time ring (bracelet) dial • Vercasson’s Foster Lambert dial • Ozanam map dial • Hologram dial
Fixed Gnomon Foster Lambert Dial(Michel Vercasson, Compendium March 2010)