Earliest records show a spoon shaped compass made of lodestone or magnetite ore, referred to as a "South-pointer", that dates back to sometime during the Han Dynasty. Ancient Chinese alchemists realized that the magnetite ore would point towards a magnetic north. The instrument was placed on a cast bronze plate called a "heaven-plate"Â that had the eight trigrams or cardinal directions, as well as the 24 directions based on the constellations. The Big Dipper was often drawn within the center disc as a reference point. The square symbolized earth and the circular disc represented heaven. Upon these were inscribed the points relating to the constellations. Its primary usage was that of geomancy to determine the best location and time for such things as burials. In Han China, where reverence for ancestors was of extreme importance, the spoon-shaped compass remained an important tool well into the 19th century. Even in modern times there are those who use this divination concepts of Feng Shui for locating buildings and locations.