One plate of an astrolabe. The usual stereographic projection (with unequal hour lines and the 12 astrological houses for latitude 43 degrees ? 40'.

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: One plate of an astrolabe. The usual stereographic projection (with unequal hour lines and the 12 astrological houses for latitude 43 degrees ? 40'. Wellcome Collection. Source: Wellcome Collection.