Museo Galileo
Virtual Museum
Proportional compasses
    • Setting:
      Room VI
    • Maker:
      Antonio Costa
    • Place:
    • Date:
      17th cent.
    • Materials:
    • Dimensions:
      length 320 mm
    • Inventory:
      Dep. GN, Roma
    • Proportional compasses (Dep. GN, Roma)

Proportional compasses with two flat legs, engraved with several proportional scales that give the limb its characteristic profile. The backs of the legs carry an arithmetical scale, a geometric scale, a scale of cubic roots, a polygon scale, and a metal scale. The front displays a chord scale, a tangent scale, the "added" scale (also found on the Galilean compass, inv. 2430), a polyhedral scale, and a scale of the ratios between volumes. Signed by Antonio Costa, about whom we have no information.