EXHIBITS > Measuring instruments, tools and machines of the ancient Greeks >
It was a simple surveying instrument suitable for measuring perpendicular angles. It consisted of four plumb lines hanging from the ends of a horizontal cross. It was used in many areas from the division of fields to the making of roads and buildings.
SOURCES: "Ptolemy, The Great Syntaxis of Astronomy (Almagest)", "Archimedes, Psammitis"