Without charts, the only means to determine a sailor or explorer's location was celestial navigation. The captain's chart was little more than the ship's log. On old maps, a circular directional emblem is a "wind rose." Mariner's in Homer's time identified direction with wind and early cartographers were part artist, part astronomer, combining wind direction into the "wind rose." Once nautical charts were initiated in the fourteenth century, the four primary winds were schematically positioned around a circle that represented the horizon. Always present was the "wind-rose," that contained a radial set of points, such as a star, directed into each wind position. The rhumb lines radiated from the central point of the rose, connected to each directional point. In the sixteenth century, cartographers expressed their most imaginative work within the rose, incorporating brilliant colors with gold and silver laced trims. Possibly through some means of uniformity, principal winds, half-winds, and quarter winds were done in different colors. Fifteenth century Italian cartographers used gold, green and red hues for their winds. Cherubs were added depicted as blowing the principal winds from their mouths and sometimes accompanied by wild animals. Where the compass and GPS set our course today, the wind rose was the primitive directional indicator on navigational charts. Early Italian wind roses displayed an east wind with an "L" for "levanter" with the west wind designated as a setting sun. A wind such as the "grecco" or northeast wind was marked with a "G". An "S" marked a "sirocco" or southeast wind and the symbol for a northwest wind or "maestro" carried an "M". The north wind originally was noted with a variety of symbols depicting celestial stars. In the 1500s, north was often marked with a symbol familiar to us, the fleur-de-lis. The discovery of the lodestone or magnetite, once touched to a steel needle, began the development of the compass.