The tower was akin to a modern-day laboratory, with an elaborate water-clock inside and sundials on the outside walls. On its eight metopes one can see personified figures of the eight winds—Boreas (N), Kaikias (NE), Apeliotes (E), Eurus (SE), Notus (S), Livas (SW), Zephyrus (W), and Skiron (NW). A rotating bronze Triton-shaped wind vane that once existed atop its roof pointed with his staff to the figure of the wind that was blowing.