Gunter quadrant with lead plumb bob made by Walter Hayes, Moorfields, London, 1648-1687. Signed with the monogram of Walter Hayes.
Gunter quadrants are mathematical instruments that were used for basic astronomical calculation and time-telling. This quadrant has a scale for measuring degrees of altitude and Gunter’s trignonometric scale for making calculations. It has a volvelle on the reverse consisting of a planispheric nocturnal.