The three-speed hoist was invented by Brunelleschi for work on the dome of Santa Maria del Fiore in Florence. Two joined horizontal wheels, working alternatively, rest on a strong structure firmly anchored to the ground, a vertical shaft. The latter operates a horizontal cylindrical shaft with two different thickness values and drags, through a spool-dented wheel system, another horizontal cylindrical shaft with yet another thickness value. The horizontal cylindrical shafts, around which the hoisting hawsers are twisted, revolve at three different speeds (corresponding to three different power levels) which are selected depending on the weight to be lifted. The machine is fitted with a safety device to prevent rotation reversal of the shafts, and operated by a pair of oxen. At the base of the motor shaft there is a worm gear device which makes it possible to raise and lower it putting one or the other of the horizontal wheels in gear with the drum pegs. This makes it possible to reverse the rotation of the horizontal cylindrical shafts (changing from raising to lowering the load) without any need to let the animals off the yoke and fix it in the other direction.