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Session 54 - Ground and Instrumentation Techniques and Catalogs.
Display session, Wednesday, June 12
Tripp Commons,

[54.08] The Colorado Equatorial Sundial

R. H. Garstang (JILA, Univ. Colo. and NIST)

The University of Colorado received from Mr. and Mrs. J. H. Tippit in 1995 a large equatorial sundial in memory of one of their sons, John Garrey Tippit, who graduated from the University of Colorado and was killed in a construction accident in 1969. The sundial is installed in the quadrangle in front of our main Norlin Library. The sundial is made of a large slab of Colorado rose-red granite, mined a few miles from Boulder. It is approximately 185 cm in diameter and 16 cm thick. The gnomon is a steel rod 7.6 cm in diameter and 205 cm in total length. The total mass, estimated from the average densities of granite and steel, is about 1400 kg, and this large mass made it impossible to make slight adjustments to the setup after installation. The sundial carries the motto "Knowledge and time abide in the same place". The sundial can be read to an accuracy of about one minute. We are making a large number of checks of the time; after allowing for the longitude and the equation of time the residuals are up to about three minutes, depending on whether one is using the winter or summer side and on whether it is morning or afternoon. We intend to analyze the errors after we have made checks for about a year.

Program listing for Wednesday