About: http://webisa.webdatacommons.org/315578037

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	He also determined the precise value of 51 arcsec for the annual precession of the equinoxes and contributed to the construction and usage of some astronomical instruments including the astrolabe.
http://www.w3.org/ns/prov#wasQuotedFrom	wikipedia.org