Many of the early sewing machines were powered by a treadle mechanism. The treadle was operated by pressing down on it with a foot, or both feet, to cause a rocking movement. This movement spins a large wheel on the treadle frame, connected by a thin leather belt to a smaller driving wheels on the sewing machine.
null. adj. 1. Having no legal force; invalid: render a contract null and void.2.ull. adj. 1. Having no legal force; invalid: render a contract null and void. 2.
Null or Nil Characteristics: 1  Etymo: Latin nullus not any, none, from ne- not, no (see un-) + illus any, dim. of unus one.. 2  Semantically: Very difficult. 3  In most cases, NULL or nil means no value or not applicable.