Assertion: windmill's sail | /r/HasProperty | replaced by patent
Facets:
Source sentences:
text: The common sails were replaced by patents; the wooden windshaft replaced by a cast-iron one; the layout of the millstones changed from head and tail to breast; a roundhouse was added to protect the trestle and provide storage space; a fantail was added to turn the mill to wind automatically, replacing the manual tailpole previously carried.