Surveyor's square

Reproduction of the Ennemain square.

This is a surveyor's square. These tools belong to the category of angle-measuring instruments known as direct-sighting instruments.

During an operation linked to the construction of the A29 motorway between Amiens and Saint-Quentin, the excavation of a Gallo-Roman rural settlement yielded a surveyor's square buried no later than the last third of the 3rd century AD.


The Ennemain square is a bronze cast by the lost-wax process, modelled over a core. It is 18.5 cm high (10 digits) and its slightly tapering cylinder is 7.67 to 7.71 cm in diameter.