Excerpt from Book of Instructions for the Equationor, or Universal Calculator
In Proportion we are instructed that it is necessary to know three quantities, so as to find the fourth quantity, and that these quantities are respectively termed Antecedents (that which precedes or is the cause), or Consequents (that which follows or is the effect) and that the three known quantities consist of an Antecedent with its Consequent, and another Antecedent whose Consequent has to be found. This leads to the Rule.