Rudimenta

Triangulation with a hinged staff. From Sebastian

Using a quadrant with a plumb bob to calculate

Cross-staffs used for surveying: in this case

Methods of surveying (right) and time keeping

Quadrant being used to obtain the altitude of

Using a quadrant with a plumb bob to calculate

Obtaining the height of a building by the use

Perotti, Niccolo, 1429 - 1480, Italian humanist