"Some will have it that the Balance, and Steel-yard derive their Origin and fundamental Principles, from these two general Axioms in Mechanicks (viz.) that Equal Weights weigh equally at equal Distances, but unequally, it unequal Distances: and this other, that unequal Weights weigh unequally at equal Distances, but that they weigh equally at unequal Distances, provided that their Distances are in a reciprocal Proportion to their Weights. Those who would be satisfied as to these Demonstrations, may find them In Guido Ubaldus, Galileus, Simon Stevin, John Buteo, in Guevara, and several other Mechanical Writers, who have enlarged very much upon this Subject."