Celestial Products

About SunVial™

 

SunVial is a sundial designed to provide the correct zone time and date without the necessity of manipulating parts of the sundial or consulting correction tables. The general shape of the sundial is cylindrical, hence the coined name of SunVial.

 

 The basic concept for the dial was inspired from the observation that during the period between solstices, the sun’s position maps to unique points in the sky for every moment of every day. Thus, a dial face for that period could be charted to illustrate common units of time and date of the sun’s location. Utilizing a small aperture (nodus) in the top of the cylinder, the sun’s image is projected onto the inner wall where a translucent sheet creates a rear view projection screen for observers. This translucent sheet is scribed with hour lines, minute division marks, and date marks to enable the user to read the time and date where the sun’s image falls. With a little practice, users can usually read the time +/-30 seconds of their actual zone time. This is a vast improvement over most commonly available sundials.

 

Setting up SunVial is a simple task. By rotating and pitching the SunVial cylinder on its special base so that the sundial reads the current time/date and is level, Sunvial is set until the next solstice.

 

Each solstice, the SunVial owner needs to merely turn the inner translucent sheet 180 degrees to bring up the dial face of the next solstice-to-solstice period. If one does not have a solstice ritual or celebration, the SunVial reset process could be a reason to start one.

 

SunVial may sit by a window, on a garden table, or on a pedestal. A bore with standard threading in the base allows SunVial to be anchored to a larger base or pedestal.

 

Each translucent dial sheet is custom scribed based on the latitude and longitude of the user’s location. Should the user move, a new dial sheet can be produced and sent for customer insertion.

 

Test marketing of the original custom-made versions has ceased. Mass market and custom models are planned utilizing a variety of materials including, acrylic, glass, brass, and stone. Inquiries or a request to be added to the SunVial “Now Available” announcement list may be directed to Larry Bohlayer at , or by phone 540-338-4040 (U.S.).

 

 

The concept and invention leading to SunVial are recorded under U.S. Patent 4,384,408.

 

 

Three views of a prototype appear below. |Celestial Products Home|

 

 

SunVial Prototype Full View

Base is made of brass and has function of allowing orientation of tube in both azimuth (360deg) and altitude (over a limited range) to set SunVial to the correct time and date.

Close-up of standard aperture nodus image.

The sun’s image is bright and is highly visible a good distance from the sundial for reading approximate times. Moving in for a closer look, one can readily determine the time and date with more precision. The translucent dial face is rotated 180 degrees on the solstice dates.

Close-up of an annulus aperture nodus image. Time shown is 12:04 pm ET on March 5th. The photo doesn’t show the center shadow dot nearly as well as the human eye can see it. (Note: The center shadow seems to be offset when in reality it is the result of the thickness of the metal at the edge of the nodus cutting off the full aperture. This will be remedied by a much thinner aperture in the production model.)