Astrolabe

Main body of this astronomical device is a round brass plate. The front and back of the plate represent the northern and southern hemispheres with their relevant constellations. This device was used to measure the changes of the solar cycles and seasons through the constellations. 360-degree gradations, the zodiac, names of major constellations, and twenty-four fortnightly periods are displayed along the circumference of the plate. Daily visible celestial area was marked by turning the hands at the center of the plate.