Quadrant, England, brass (17th century)

Quadrant, England, brass (17th century)
Accession number: 
Inv. 45309
History of Science Museum, University of Oxford

Like the mariner’s astrolabe, quadrants were navigational instruments used to measure the altitude of points in the sky. When the user lines the sights up to a star, the string is pulled down by a weight (called a ‘plumb bob’) and indicates the relevant measurement on the arc’s scale. The plumb bob here is in the shape of a heart.

On Loan from the History of Science Museum, University of Oxford, Inv. 45309


Quadrant used to  measure the height of a building, detail in Sebastian MünsterRudimenta mathematica (Basil, 1551) ©Max-Planck-Institut für Wissenschaftsgeschichte