Ingleside Terraces Sundial
sundial geographic north The gnomons of horizontal sundials in the northern hemisphere point to geographic north, the North Pole, but how accurate is the layout of the 1913 Ingleside Terraces Sundial?
In the accompanying google satellite view of the IT sundial, the gnomon appears to point to the right, but that is due to camera not being directly overhead.

The IT sundial is surrounded by four hearts, the apices of which point in the cardinal directions, north, east, south, and west. The centers of the hearts originally had plantings that formed the directions N, E, S, W historic sundial photo.  The plantings have been replaced by letters in this photo.

A vertical line placed using Photoshop starting at the north apex goes through the center of the sundial and also intersects the south apex, showing that the placement of the IT sundial is accurate within a fraction of a degree.

The four classical columns are in the ordinal directions:

  • SW Doric
  • NW Ionic
  • NE Corinthian
  • SE Tuscan
The horizontal line between the west and east heart apices goes through the center of the sundial.
The base of the gnomon is in an east-west line with the 6 A.M. and 6 P.M. Roman numerals (and also with sunrise and sunset at the vernal and autumnal equinoxes).   The base of the gnomon is approximately 5/9 of the distance between the center of the sundial and the inner aspect of the dial with the Roman numerals, corresponding to this sundial being located at approximately 5/9 of the distance between the north pole and the equator.

pyramids geographic north Egyptian pyramids from 2500 B.C. are also aligned in north-south, east-west directions.
A compass points to magnetic north, not to geographic north, but there are several ways to determine geographic north.
Put up a vertical pole and place stones at the end of its shadow multiple times throughout the day. The location with the shortest shadow, which occurs when the sun is farthest north, points to geographic north.
Or from a starting point, place markers at sunrise and sunset and connect the markers with a line. The line will be east-west and a line at right angles to the east-west line will be north-south.

Ingleside Terraces Sundial links:
Google map, directions to the Sundial
Ingleside Terraces Sundial, Then and Now Photos
Ingleside Terraces Giant Sundial
Kite Aerial Photographs
Sundial History

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Robert Karis
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