About: http://webisa.webdatacommons.org/137089481

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	In order to get millimeter waves, you had to use a short spark gap, and a short spark gap is a gap that is so small it is just about the mean-free path of an electron in air, in atmospheric pressure.
http://www.w3.org/ns/prov#wasQuotedFrom	ethw.org