About: http://webisa.webdatacommons.org/359722782

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	He finds that for glass, brass, antimony, and some other substances, the attraction is the same (given the same masses and distance), to i part in 20 million.
http://www.w3.org/ns/prov#wasQuotedFrom	wikisource.org