Description

later as Balenus hameri with two enlarged details A-B showing open and closed states

Allan Harris of QPR

American Wonders

Scene showing William Boyd

Astronomical quadrant Size:XL: 100 x 75cm later as Balenus hameri withA 12 inch astronomical quadrant made by John Bird. Astronomical quadrants were used to measure the angle of a celestial object from the zenith. Operated in conjunction with a transit instrument, they could be used to check the running rate of astronomical clocks known as regulators. At sea a quadrant can be used to help fix a ship's position and to determine latitude. ca. 1767

Exchange/Return Notes