Geometry and Possible Calendar Functions at The Ghost Eagle Site (Richland Country, Wisconsin)
By: Prof. James P. Scherz Madison, Wisconsin
This report addresses geometry and possible calendar functions at the effigy mound group located on the north bank of the Wisconsin River, near Muscoda, Wisconsin. In the 1800’s this extremely impressive group of eagle mounds was called “The Eagles”. Today, we refer to it as the “Ghost Eagle Site”. The latter name was coined by Jan Beaver, an artist from New York, who in 1992 became infatuated with this mound group. She devoted more than a year of intense effort on studying this large collection of earth art work. Through her efforts, we were able to merge historical surveys of these mounds, made by T. H. Lewis in 1886, with modem surveys of the few mounds that remain. And by use of historical aerial photos analyzed on a stereoplotter (a precise machine for making maps from aerial photos) we were able to locate the image of a giant eagle mound which, like a ghost, expressed itself in the different rates of ripening oats. These patterns were evidently caused by differences in soil where the mound had once been located From our precise mapping methods, we could tell that this ancient eagle mound was oriented to the direction of the winter solstice sunset on the shortest day of the year (about 21 December). The body of this mound was oriented directly to the setting sun on the winter solstice, and its long, straight wings at right angles to this direction. Although plowed down by agriculture and not readily recognized in the field even when one is located near the mound, this ancient image appeared like a clear ghost in aerial photos from 1968. Even its beak was clearly indicated, pointing to the northwest in the direction of where the sun will set after the winter solstice.
As with other mound groups, we find geometry in the Ghost Eagle site that is related to setting the solar calendar-a calendar related to the cold and warm seasons of the year. Any agricultural people in this part of the world must have such a functional solar calendar, lest the crops be planted to late and not ripen or be planted too early and freeze in the late frosts of the spring. A solar calendar is set at times we call the solstices or the equinoxes. On the equinoxes (about 21 March and 21 September), the sun is located on the celestial equator and will rise and set directly on an east-west line. On the summer solstice (about 21 June) the sun’s declination (angle north or south of the equator) is about 23.5 degrees north, and the sun will rise and set at its extreme position north of an east-west line. Similarly on the winter solstice, when the sun’s declination is about 23.5 degrees south, the sun will rise and set at its extreme southern location.
These four times in the solar calendar determine the beginning of what we call spring, summer, fall, and winter. They correspond in graphical form to the four cardinal points of a compass (east, south, west and north). But many ancient cultures also used what we refer to as cross quarter days. Cross quarter days are midway between the equinoxes and solstices, dividing the year into eight parts. In graphical form, they correspond to the other directions on a mariner’s compass (N, NE, E, SE, S, SW, W, and NW). We preserve some of the approximate times of these ancient festivals in our modem calendar as Halloween (also All Soul’s and All Saint’s Day following Halloween), Ground Hog’s Day, and May Day. In some ancient cultures, a festival in August (between the summer solstice and the autumnal equinox) was devoted to celebrating the first fruits from the fields. Our Halloween with its skeletons and witches (names for ancient pre-Christian holy women) relate to the Old World festival at the fall cross quarter day when people remembered and honored their departed relatives. A similar honoring was practiced in the pre-Columbian New World on the same cross quarter day. It is still practiced in Mexico as the day or feast of the dead. As in the Old World, there are visits to grave yards and skeleton decorations.
Similar to other mound groups we have analyzed, we see alignments at the Ghost Eagle Site that suggest a calendar devoted to equinoxes, solstices, and ceremonies between these times, some at the cross quarter days and some a month before or after the equinox.