15th and 16th century instruments including equatorial armilla, astronomical sextant and azimuth theodolite at the ancient observ

air ancient antique armilla art artistic asia asian astrology astronomical azimuth beijing bronze building celestial china chinese circles cityscape courtyard craftsmanship decorated equatorial equipment fence frost gazing instrument jesuit landmark metal object observatory old oriental ornate outdoors platform pollution pretelescopic retro rooftop sextant sky skyline snow sphere star stargazing stone technology theodolite urban vintage winter