Astronomical quadrant mb-width 3790 Buckingham Palace forecourt

Buckingham Palace forecourt

'Ladies buy your leaf

Showing an improvement proposal for sea-water swimming pools

The front of the car concentrating on the bumper

View of the east end of the church before restoration

Astronomical quadrant mb-width 3790 Buckingham Palace forecourtA 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