About: http://webisa.webdatacommons.org/110659949

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	The mast is a necessary and very obvious element of a portable cable tool drilling machine and has remained so throughout the tenure of these machines, even their present-day counterparts.
http://www.w3.org/ns/prov#wasQuotedFrom	petroleumhistory.org