| 摘要 |
A universal sundial which indicates watch time is constructed from a standard pipe section or cylinder with one end an elliptical plane at an angle to the axis of the cylinder preferably within approximately 15 DEG of the latitude of the proposed site. The gnomon is a small sphere located at the center of the elliptical plane end. Time, sun declination, latitude, and meridian displacement indicia are all located on the inner surface of the cylinder by angular coordinates from the center of the gnomon. Two cylinder or two removably attachable overlays are required for indication of civil time for a full year. The sundial is set up by orienting it so the shadow of the gnomon indicates the correct time when the gnomon is in a vertical position over the site latitude and meridian or meridian displacement indicia.
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