counterpoise vs equiponderance

counterpoise

noun
  • A weight sufficient to balance another, for example in the opposite end of scales; an equal weight. 

  • The relation of two weights or forces which balance each other; equilibrium 

  • An effect of equal power or force acting in opposition; a force sufficient to balance another force or influence 

verb
  • To act against with equal weight; to equal in weight; to balance the weight of; to counterbalance. 

  • To act against with equal power; to balance. 

equiponderance

noun
  • The state of being equal in weight; equipoise 

How often have the words counterpoise and equiponderance occurred in a corpus of books? (source: Google Ngram Viewer )