About: http://webisa.webdatacommons.org/243406441

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	plete and self-sufllcient ventilating system and obviating the necessity for a separate ventilating system, such as is usually provided where drilling is carried on in confined areas.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com