About: http://webisa.webdatacommons.org/172288261

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 canaries were retired when electro-chemical sensors were developed to monitor chemical processes and measure variables, such as resistance, to detect the build up of gases.
http://www.w3.org/ns/prov#wasQuotedFrom	phys.org