<http://webisa.webdatacommons.org/165890640>	<http://www.w3.org/ns/prov#wasQuotedFrom>	<freepatentsonline.com> .
<http://webisa.webdatacommons.org/prov/111526749>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/165890640> .
<http://webisa.webdatacommons.org/prov/281379518>	<http://www.w3.org/ns/prov#wasDerivedFrom>	<http://webisa.webdatacommons.org/165890640> .
<http://webisa.webdatacommons.org/165890640>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/prov#Entity> .
<http://webisa.webdatacommons.org/165890640>	<http://www.w3.org/ns/prov#value>	"Accordingly, if a gas such as air is heated at the bottom of a vertical duct (i.e., chimney flue) and a much colder air exists at the top of the duct, the heated air will rise through the duct causing a draft." .