About: http://webisa.webdatacommons.org/409268971

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	When the air-chambers are of rubber the larger balsas are usually kept empty until wanted, when the air-chambers are inflated by means of a sort of bellows and tube.
http://www.w3.org/ns/prov#wasQuotedFrom	maritime.org