MARK WILLIAMSON / SCIENCE PHOTO LIBRARY MARK WILLIAMSON / SCIENCE PHOTO LIBRARY
One of several historical Chinese astronomical instruments on the roof of the Beijing Ancient Observatory in Beijing, China, an astronomical observatory that dates from the 1400s. The equatorial armilla (1673), or armillary sphere, was designed to measure true solar time and right ascension and declination of celestial objects.
Model release not required. Property release not required.