Photo Descriptors - The Denver, CO Equatorial Sundial ROW 1 No. 1 (140_4001_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 (139_3988_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. ROW 2 No. 3 (140_4006_r1.jpg) - The gnomon of a properly oriented equatorial sundial points toward the Celestial North Pole. No. 4 (139_3992.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 Cranmer Park sundial gnomon angle of inclination = ~39 degrees; dial plate angle of inclination = ~51 degrees. ROW 3 No. 5 (140_4007_r1.jpg) - Note Rocky Mountain peaks visible along the western horizon (background). No. 6 (140_4010.jpg) - The red sandstone used to make the sundial in Cranmer Park came from Lyons, Colorado (north-northwest of Denver). The tiles of the flagstone plaza are made of red sandstone as well. Sundial reads 12:30 p.m. Local Apparent Time (L.A.T.). ROW 4 No. 7 (139_3971_r1.jpg) - At local solar noon, a.k.a. Sun transit, the gnomon shadow is congruent with your meridian. Sun transit occurred at 12:46 p.m. MDT on 12 OCT 2003. Note: sundial reads 12 noon L.A.T.; Global Positioning System (GPS) receiver display reads 12:46 p.m. MDT. The apparent discrepancy between solar time and standard time is caused by: 1) the Equation of Time (EoT); 2) the difference in longitude between the location of the sundial and the Standard Time Meridian (STM) for the Mountain Time Zone (MTZ STM = 105d W); and 3) Daylight Saving Time. No. 8 (139_3983_r1.jpg) - Sundial shows ~12:14 p.m. L.A.T.; GPS receiver display shows 1:00 p.m. MDT. ~12:14 p.m. L.A.T. minus 13.4m EoT = ~12:00 noon MST; add one hour for Daylight Saving Time = ~1:00 p.m. MDT. (Note: In this case, the difference in longitude between the sundial location and MTZ STM is negligible.) GPS receiver display shows the exact elevation of the sundial: 5,434 feet above sea level (see photo No. 18). ROW 5 No. 9 (139_3979_r1.jpg) - Wrist strap of GPS receiver looped around sundial gnomon, upper dial face. No. 10 (139_3982_r1.jpg) - GPS receiver (hanging from gnomon) showing exact location of sundial (+/- 32.5 ft.): N 39d 71.921m, W 104d 93.474m. ROW 6 No. 11 (140_4094.jpg) - Plaque located in-ground, to the right of the gnomon, lower dial face. Note: Original sundial, commemorated in 1941 (see photo No. 12), was replaced in 1966. No. 12 (140_4097.jpg) - Close-up of text, Equation of Time (EoT) graph, in-ground plate located next to lower dial face (southern side of sundial). Transcript of inscription: 'Read upper edge of shadow. Add or subtract number of minutes shown here for the current date. The result will be watch time. The reading on the sundial shows the visible Sun's time here. Watches are set to the average time at the 105d meridian (7 hours west of Greenwich, England) which lies along Navajo Street, Denver, and is 17 seconds of time west of here. The 40th parallel of north latitude, along which are Boulder, Lafayette and Brighton, lies 0d17m north of this site. The axis of this sundial is elevated 39d43m. It points now about 1d from the North Star to the pole of the heavens. The stone is elevated at 50d17m to be parallel to the Equator. 1941' ROW 7 No. 13 (140_4047.jpg) - The Cranmer Park sundial was designed by Stephen A. Ionides. Ionides' signature is inscribed on the lower-right side of the EoT graph next to the upper dial face (northern side of the sundial). The original sundial was produced by master stonecutter John Earl Herschberger, Erickson Memorial Company. No. 14 (140_4049.jpg) - 'Ancient Chinese type Sun dial.' The preceding quote appears on the lower-left side of the EoT graph next to the upper dial face (northern side of the sundial). Naturalist Dean Babcock, one of the first forest rangers in Rocky Mountain National Park, reportedly was associated with Stephen A. Ionides in designing and setting various sundials in Colorado. When George Cranmer, former manager of parks and improvements in Denver, CO, decided to place a sundial of Chinese tradition in Mountainview Park (now known as Cranmer Park), Babcock helped Ionides by translating Chinese characters into Arabic. ROW 8 No. 15 (140_4086.jpg) - ~5:07 p.m. L.A.T., or ~5:53 p.m. MDT. No. 16 (141_4108_r1.jpg) - View from the southwest, looking up the steps to the flagstone plaza (foreground) and across the 'mountain view panorama' (see photo No. 20) located along the western side of the plaza. ~5:22 p.m. L.A.T., or ~6:08 p.m. MDT. ROW 9 No. 17 (140_4069_r2.jpg) - Cranmer Park, originally known as Mountainview Park, was renamed after conservationist George E. Cranmer, former manager of parks and improvements in Denver, CO. No. 18 (140_4099.jpg) - Cranmer Park's elevation is 5,434 feet, or 1.029 miles above sea level. (Note: 1 mile = 5,280 feet.) ROW 10 No. 19 (141_4103.jpg) - No. 20 (140_4041_r1.jpg) - The 'mountain view panorama' is a geographic profile that shows the name and elevation of the peaks of the Front Range of the Rocky Mountains, visible to the west of Cranmer Park (formerly known as Mountainview Park). ROW 11 No. 21 (140_4033.jpg) - No. 22 (141_4140.jpg) - ROW 12 No. 23 (141_4105.jpg) - No. 24 (141_4117_r1.jpg) - Sunset: 6:26 p.m. MDT, 12 OCT 2003.