Horary quadrant of boxwood marked with Gunter scales. The brass sights are intact, the plumb is present but seems to be of later date. As is common with boxwood quadrants, the reverse has no nocturnal dial and is blank. The outer circle has a graduation of 0-90 degrees for height measurement. The sights are aimed at the celestial body, the plumb line then indicates the height to an accuracy of 1 to 2 degrees.
For astronomical observations the middle ring shows a representation of the sky with five stars are marked and named: Wing of Pegasus, Arcturus, Lions Heart, Bull’s eye and Vulture’s heart. Geometrical square in apex with the table of R.A’s of these stars. Latitud 51 30, the latitud of Greenwich.
Further to see: showing time and sun’s azimuth, equinoxes at 21 March and 23 September and linear shadow scales.
Copies of this quadrant are to find in the National Maritime Museum of Greenwich, in the Science Museum and in the British Museum.

Catalogue: NM.7-08
Date: ca.1675
HWL: 10x128x125 mm
Signed: not signed
Origin: probably English
Condition: excellent