Diagram MAPD0341

Equinoctium: The diagram represents the balance between added lengths of daylight and subtracted lengths of daylight in the three months before and after each solstice. Three concentric and equidistant semi-circles, extended to form horseshoe-shaped lines, set the framework for this diagram. Within the innermost of the three, a straight line bisects the space and extends to become parallel with the legs of the horseshoe shapes. The six ends of the horseshoes are numbered. From the outside in on each side of the figure the three legs are labeled with numerals, one to three, and often with the words for "first", "second", and "third" as well. The label, "equinoctium", appears in the curved section of the diagram.