The Arab authors indicate that the lighthouse was constructed from large blocks of light-coloured stone, the tower was made up of three tapering tiers: a lower square section with a central core, a middle octagonal section, and, at the top, a circular section. At its apex was positioned a mirror which reflected sunlight during the day; a fire was lit at night. Extant Roman coins struck by the Alexandrian mint show that a statue of a Triton was positioned on each of the building's four corners. A statue of Poseidon or Zeus stood atop the lighthouse.[10] The Pharos's masonry blocks were interlocked, sealed together using molten lead, to withstand the pounding of the waves.[11]