A free standing stained glass
dyptich sundial
The model was built in 1995 and has deteriorated a bit. The lines and curves were generated by program I wrote for DesignCAD - a DOS based graphics program. The design was then printed on mylar with a laser jet printer.

The stained glass faces south.

Below The side view. The numerals are upside down. Their shadow will invert when they fall on the platen to the right.
Below is a view of the platen. The time is told as the shadows of the stained glass pattern move across the platen during the course of the day. The "bead" is the indicator.

On the summer solstice the shadow of the upper curves will travel across the bead. Simarly, the lower curves at the winter solstice. The straight lines represent the equinoxes.




Listing from
Stained Glass Sundials: 20th & 21st Centuries (1900's & 2000's)
Site by John L. Carmichael (author) and Dave Bell (webmaster)>
This is dial #5
Designer: Robert Terwilliger
Date: March, 1995
Original Location: drawing appears in NASS "Compendium" (Vol. 2-1, 03/95, p12.
Ave Amici by L. Papirius Cursor)
Orientation: Vertical. Faces south and made for 40 N. and adjusted (tilted) to work at 25 N.
Size: pedestal size
Adornment: none
Mottos: none

Comments: This is a conceptual drawing. This type of dial was recently invented in 1994 by Dutch dialist Thibaud Taudin-Chabot. There are no known full-scale examples of this extremely rare sundial type installed anywhere. When lit by the sun, the sundial face on the glass projects its image onto a receiving surface.

In a building, this could be a wall or a floor. The sundial doesn't have a fixed gnomon attached. Instead, the gnomon is simply a dot on the receiving surface. As the sun moves across the sky, the projected sundial image moves across the receiving surface. The location of the dot gnomon on the projected image indicates the correct time and can also indicate the date.

The lack of a three dimensional gnomon makes this type of dial more resistant to damage. Projection dials such as this must have transparent glass or plastic that's colored or clear. They can't have translucent opalescent glass

Article by Robert Terwilliger: (March 1995). Ave Amici. "The Compendium" Vol. 2-1 pg. 12 NASS