Topics related to Sundial Mailing List
May 2007: Prius Sundial
The antenna of my Prius exits the roof at a 48 degree angle, so how could I resist turning it into the gnomon for a"fast" sundial? The dial is configured for 48 degrees, but I live at 44.5 degrees, so for it to work I need to park facing south on a 3.5 degree incline. The nodus is a foam basketball, and is really just to make the car easier to find in a large parking lot, as there are no declination lines for it to mark. Antennas like these are now common on many cars, and easily unscrew for taking the car through a carwash.
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Policeman: How are you so sure the accident occured
at 1:15? Me: Because, officer, I had one foot on the accelerator, one hand on the wheel, and my upper torso was sticking out of the driver's window, craned backwards to read the time off my sundial! |
August 2006: Sundial Cannon
| I bought a reproduction of a sundial cannon on ebay about a year ago, and finally got around to testing it out. I'm not sure who made it, maybe the Franklin Mint, but the darn thing works! See and hear the video by clicking on the adjacent picture. |  |
| The cannon uses about a gram of gunpowder. Some is spread across the channel at the top where it is ignited by the focused sunlight. The holes lead to the cannon's barrel. I stand in front of the lens when I place the powder here, so my shadow keeps the thing from going off accidentally! |
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November 2005: Homan Heliochronometer photos courtesy of Tony Moss of Lindisfarne Sundials.
Notice that the lower left image has the numbers running counter clockwise. Originally I thought this meant it was a Southern hemisphere model, but Andrew James pointed out that the numbers are engraved on the rotating alidade rather than the fixed rim, and hence are supposed to run counterclockwise for the Northern Hemisphere. He is right, but I had to think about it for a while.
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September 2005: Time Lapse Camera
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To film the 80 minute time lapse movie of the Odyssey of Light (see Consult Page), I built this automated device from my son's Kinex set. It took a photo every 20 seconds, and to my relief, worked flawlessly! Here is a 8 second movie of it running (Kinex Movie, 2.8 megabytes). |
January 2004: Unfinished Schmoyer Design
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Richard Schmoyer's daughter, Laurel Browning, shared this sundial design he never finished. It appears to be an equatorial dial designed to be mouned high on a wall, such as over a doorway. |  |
December 2003: Focused Sundial Cursor
I finished my double focusing sundial (Renaissance style) in December 2003. My intent was to make a shadow, or "cursor", for reading the time that was only a few seconds wide with crisp, sharp edges. I was able to accomplish this by using two sets of focusing mirrors to project two focused beams of light, side by side, and spaced apart by just a thin sliver of shadow. These photos show the set-up and the results. Here is a 45 second movie of the beam moving in real time, compared with a watch. Here is a link to the Renaissance (single focusing mirror) sundial page.
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Here the dial reads (right to left) 12:16 and 40 seconds. The cursor is only about 10 to 15 seconds wide. |
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Two rows of mirrors cast the two focused beams of light. |
Email to: Bill Gottesman, managing member
