The globe sundial will show light and dark sides of the stone in sunshine. The terminator line separates the two and the hour numbers show the time.
This stone globe was initially puzzling. It has a band of hour numerals and looks like a type of sundial. It is actually a globe terminator dial. The hour band lies parallel to earth’s equator, and the line between light and dark shadow in sunshine is the terminator. The puzzle was why the globe had a second sundial stone fixed onto it, since removed in the workshop, as a later post will explain.
The stone is in excellent condition. The hour numerals are sharp and uniform. The dots cut into the stone are the hour points with half hour and quarter hour points as well. A terminator sundial has the hour ’12’ cut twice, on the East and West sides, opposite each other. This is where the terminator line falls at noon, which is midday. The hour ‘6’ is also cut twice, on the South and North sides of the stone, and the other hours follow a similar pattern. At Spring and Autumn Equinox, sunrise is 6am and sunset is 6pm.
When it was made, this sundial was never a precise instrument for telling the time, mainly because its terminator is not sharp, it will be a soft shadow line even in bright sunshine. This object is for the fascination and interest of mathematics and astronomy. It probably dates from the 17th century when people loved to discuss and explore new scientific ideas.