Photo Descriptors - The Brighton, CO Equatorial Sundial ROW 1 No. 1 (145_4539_r1.jpg) - An equatorial sundial is actually a reduced model of the Earth, similar to a globe with its upper and lower halves removed: the dial plate represents the plane of the Earth's Equator; the gnomon represents the Earth's axis of rotation. No. 2 (145_4529_r1.jpg) - The gnomon is the part of a sundial that casts the shadow used to tell time. For equatorial sundials, the gnomon is a pole (or rod) of varying thickness. The gnomon shadow falls on the upper dial face from the MAR Equinox to SEP Equinox; the gnomon shadow falls on the lower dial face from the SEP Equinox to MAR Equinox. Date/Time Original: 2003:11:08 / 16:29:36 (~4:30 p.m. MST) Gnomon shadow = ~4:45 to 4:47 Local Apparent Time (L.A.T.) Equation of Time (EoT) = -16.3m ~4:46 L.A.T. - 16.3m EoT = ~4:30 p.m. MST (same time indicated by photo metadata) ROW 2 No. 3 (145_4567_r1.jpg) - The gnomon of a properly oriented equatorial sundial points toward the Celestial North Pole. No. 4 (145_4550_r1.jpg) - The gnomon should be parallel to the Earth's axis, inclined at an angle equal to the latitude of the observer. The dial plate should be parallel to the plane of the Earth's Equator (perpendicular to the gnomon), inclined at an angle equal to the complement of the observer's latitude. This angle is also known as the colatitude. The Brighton, CO sundial gnomon angle of inclination = ~40 degrees; dial plate angle of inclination = ~50 degrees. ROW 3 No. 5 (145_4545_r1.jpg) - Wrist strap of GPS receiver looped around sundial gnomon, upper dial face. Note: Location inscribed on sundial is nearly identical to location displayed by GPS receiver (see photo No. 6). No. 6 (145_4548_r1.jpg) - Close-up, Garmin GPSmap 76S GPS receiver showing exact location of sundial (+/- ~15 ft). Elevation: 5030 ft Accuracy: 14.8 ft Date/Time: 08 NOV 03 / 16:38:57 MST Latitude: N 39.92538d Longitude: W104.87789d ROW 4 No. 7 (145_4576_r1.jpg) - Upper dial face as viewed from the north (facing south). The upper dial face represents the Northern Hemisphere; the lower dial face represents the Southern Hemisphere. No. 8 (145_4582.jpg) - Close-up of text, upper dial face (northern side of sundial). Transcript of inscription: 'Spring and summer read this side. Tempus Fugit - Time Flies. This equatorial Sun dial was erected for your enjoyment on November 21, 2000. Funds provided by Adams County Cultural Council, Adams County Historical Society, and Scientific and Cultural Facilities District. Brighton, Colorado. Longitude W104.8, latitude N40.0. 7 hrs. west of Grenwich [sic] England.' Note: The Prime Meridian is located in Greenwich, England (pronounced, 'gre-nich'). ROW 5 No. 9 (145_4569_r1.jpg) - Lower dial face (southern side of sundial). Transcript of inscription: 'Fall and winter, read this side.' No. 10 (145_4572_r1.jpg) - View from the southwest (facing northeast). ROW 6 No. 11 (145_4540.jpg) - Graph, Equation of Time (EoT) used to correct solar time for standard time. Transcript of inscription: 'In spring and summer read right edge of shadow in a.m., left edge of shadow in p.m. Add or subtract number of minutes shown on chart for current date. The results will be standard watch time for this area. Subtract [sic] one hour for Daylight Savings [sic] Time.' Note: Add one hour for Daylight Saving Time. No. 12 (145_4577.jpg) - Graph, Equation of Time (EoT) used to correct solar time for standard time. Transcript of inscription: 'In fall and winter read left edge of shadow in a.m., right edge of shadow in p.m. Add or subtract number of minutes shown on chart for current date. The results will be standard watch time for this area. Subtract [sic] one hour for Daylight Savings [sic] Time.' Note: Add one hour for Daylight Saving Time.