sundial

The idea for the sundial element of the Gaber Solar Clock Garden emerged from a presentation at a summer research conference in 2000 attended by Matt Beaky, associate professor of physics. and Scott Ellis, dean of science. Dr. Beaky said that after seeing the presentation on a university sundial, the same idea occurred to both of the professors: "Why not build one at Truman?"

Dr. Beaky assigned students in his spring 2001 JINS class – Astronomy and Early Human Culture – to work in teams and to develop design ideas for a Truman sundial. He then developed a final design based on the students' proposals. This design incorporates a vertical gnomon to cast the shadow, hour lines to mark the time of day, and solstice and equinox lines to mark the passing of the seasons.

The sundial occupies a gently sloping site, 30 feet wide by 90 feet long, at the south end of the newly renovated Magruder Hall. Located between the greenhouse and the sidewalk along Patterson Street, the sundial serves a practical as well as an educational purpose.

The sundial tells local apparent time, which differs from "clock time" because of the displacement of Kirksville from the standard meridian for the Central Time zone, the irregular annual motion of the Sun, and the observance of Daylight Savings Time. Between the months of April and October, add one hour to the times shown on the diagram above.

Gnomon: Made from a cedar tree that once stood on the Solar Clock Garden plot, the gnomon is a 12 foot high, vertical post that casts a shadow which indicates the time of day and the season of the year.
Equinox Line: The sun's shadow follows the straight vernal and autumnal equinox line on March 21 and September 22.
Summer Solstice Line: The short, curved line closest to the gnomon indicates the path of the tip of the gnomon's shadow on the summer solstice, around June 21.
Winter Solstice Line: The long, curved line farthest from the gnomon indicates the path of the tip of the shadow on the winter solstice, around December 21.