About: http://webisa.webdatacommons.org/431496630

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	Some sextants also feature an artificial horizon, a mirror that reflects a bubble in a fluid-filled tube, which can be helpful when the real horizon is obscured by fog or other obstacles.
http://www.w3.org/ns/prov#wasQuotedFrom	wisegeek.com