Abstract

Medicine Wheel is a name given to several kinds of circular or radiating patterns of stones placed on the ground by man. It is unlikely that all kinds of medicine wheels served the same purpose (Brumley 1988). The Majorville Medicine Wheel in Southern Alberta (50.586? N latitude, 112.410? W longitude) has associated with it outlying rock lines and cairns that accurately mark the sun rise and set points on the solstices and on the observed equinoxes. The point of the sun's first flash on the horizon is the rise position, and the point of the last flash on the horizon is the set position. These points move northward from December to June, then move southward again after the summer solstice. Near an equinox the sun rise and set points at Majorville move along the horizon by 1.3 sun diameters per day. Near a solstice it takes nine days to move the last diamcter to the solstice position. We determine the sun rise and set points photographically to within less than one sun's diameter, and sometimes to within a fifth of a diameter (0.1?), along alignments up to 2km long. Rock alignments at Majorville mark the sun rise and set points three days before the vernal equinox and three days after the autumnal equinox. These days are within two minutes of being exactly 12 hours long. The lens effect of the atmosphere causes the length of the solar equinoctial days to be about 12 hours and 10 minutes long at Majorville. The position of sunrise on the 12.00 hour day is marked by a spoke in the Medicine Wheel, which points to a large white limestone in the East House 61m away, and to a configured part of the eroded river bank 1100m away. Rocks have slid down the eroded bank from the sightline position. The sun rises over the horizon about 30km distant. A more spectacular 12.00 hour day sunrise marker involves two V sights of rocks separated by 70m, on the west side of the Medicine Wheel hill. The sighting line is tangent to the Wheel. Because one is looking up the shaded side of the hill, the sun becomes visible in the nested bottoms of the V's a half hour after the first flash on the distant horizon. Thus, one can observe the equinox sunrise even if the distant horizon is overcast to a depth of several sun diameters. The 12.00 hour day sunset is marked by a spoke of the Wheel which points to a small cairn on a hillock 1100m away and to a ripple on the horizon about 10km distant. The important part of the Majorville Medicine Wheel site covers 13km. It is 20,000 times larger than previously thought. The area protected by Alberta Government designation has been increased from 0.16km to 0.65km. The designated area should include all of sections 2, 3, 10 and 11 in township 19, range 18, west of the 4th meridian, and also the E half of 4-19-18-4 and the steep banks on both sides of the Bow River in sections 1, 12, 13 and 24 of 19-18-4, and the banks in sections 24, 25, 34 and 35 of 18-18-4.