Unlike regular dividers, proportional dividers have points at both ends. A screw and nut slide along a slot within the legs to allow the instrument to be opened into an "X" shape. The user then tightens the screw at a particular proportion in order to make scale drawings, such as for engineering or architecture. Proportional dividers are especially helpful when the drafter must change between several different scales. However, for one of these objects, there was only one desirable proportion, the so-called "universal ratio" of 5.333:1. Maurice Kidjel, a Hawaiian artist and inventor, sought out and received publicity for his device in the 1960s.
