Assertion: boomerang's shape | /r/HasProperty | improvement
Facets:
value: to the design
type: OTHER
Source sentences:
text: Based on previous work done by William S. Webb, William R. Perkins claims that spear-thrower weights, commonly called "bannerstones", and characterized by a centered hole in a symmetrically shaped carved or ground stone, shaped wide and flat with a drilled hole and thus a little like a large wingnut, are an improvement to the design that created a silencing effect when swung.