An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A type of → astrolabe in which the observer's horizon is drawn on the surface of a globe, mounted with a freely rotating spherical lattice work or 'spider' representing the celestial sphere. The earliest description of the spherical astrolabe dates back to  the Iranian astronomer Nayrizi (865-922).

→ spherical; → astrolabe.