About: http://webisa.webdatacommons.org/424359348

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	Here we encounter a problem: it is necessary to use two zenith measurements to characterize an arc along a meridian, but the scale factor determined earlier was a function of a single zenith measurement.
http://www.w3.org/ns/prov#wasQuotedFrom	mathforum.org