In the semicircular arches above the clock faces are a set of carved and decorated keystones. On the north side is the head of an Inuit male; on the south, the head of a Khoikhoi male; on the east, the head of a Chinese male; and on the west, the head of a Native American male, which refer to the four corners of the globe. Lower down, above a pair of windows, is a stylised relief carving of a half-length bearded male holding a scythe with wings spreading out behind him. Below, above another pair of windows, are two further relief designs: a sun with rays radiating outwards, and a quarter moon surrounded by a circle of stars, illustrating the theme of day and night.