chorobates
The chorobates was a surveying instrument used by the ancient Romans for measuring horizontal distances and leveling ground. It was essentially a long wooden beam, typically about 20 feet in length, supported by adjustable legs. Along the top of the beam, a groove was carved and filled with water. A plumb line was also suspended from the center of the beam.
The principle behind the chorobates was to create a stable and level reference. By adjusting the legs