Assertion: windmill's sail | /r/MadeOf | self-regulating
Facets:
Source sentences:
text: In 1807 Sir William Cubitt invented his “patent sail” combining Meikle’s hinged shutters with Hooper’s remote control by chain from the ground via a rod passing through a hole drilled through the windshaft; the operation was comparable to operating an umbrella; by varying the weights hung on the chain the sails were made self-regulating.