Mechanical devices for solving quadratic and cubic equations

Abstract

The apparatus consists of a base piece with central line X'OX •carrying on OX a uniform scale suitably graduated. An upright piece OY is fixed rigidly at right angles to the base piece and carries a scale marked " y " at R, where OR = \/y. An arm PQ, made of transparent material, can rotate about the pivot P, which is attached to a slide moveable along X'O, and carries a uniform scale whose unit is half that of the OX scale.