This group of stars is probably one the best known constellations in the night sky. Since man first began to group the stars into some order this figure has been recognised as a bear, eternally drifting around the celestial pole. In Britain it is commonly called the "Plough" after the tale of Hu Gadarn, and can be seen on every clear evening as the major constellation of a collective group called the circumpolar stars. Every kind of civilization has legends regarding it, from the Chinese to the American Indians. Ursa Major is one of Ptolemy's original constellations, and is an ideal tool that will enable the beginner to find his way around the northern sky. In mythology they were Callisto and Arcas, a mother and son. Callisto was one of the servants of Artemis, who turned her into a bear over some imagined slight. Her son, Arcas, out hunting came across the bear and was about to slay it when Zeus changed Arcas into a bear too and placed both amongst the northern stars.