Remarkable architectural and topographic instrument, predecessor of the present plummet, which was used to calculate the inclination of several surfaces, in topographic sightings etc. The instrument describes Heron from Alexandria in his work Peri Dioptras, explaining the way, with which the engineer Eupalinos from Megara incised the known Eupalinion ditch in the present Pithagorio of Samos, in 520 B.C. The chorobates is considered to be a necessary supplement of the other significant instrument of Heron, the dioptra.
