About: http://webisa.webdatacommons.org/256966682

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	not subject to vibrations and other noise, so the master clock will run more accurately
http://www.w3.org/ns/prov#wasQuotedFrom	clockhistory.com