About: http://webisa.webdatacommons.org/5843495

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	In the early 1940s, navigation was a matter of visual identification and 'dead reckoning.'
http://www.w3.org/ns/prov#wasQuotedFrom	pbs.org