A brass carriage with two freely turning wheels can roll down the slope, raising light weights or roll up the slope on being pulled by the weights. The carriage and the small platform on which the weights are placed are connected by means of a string running through a pulley at the end of a rod fixed to the top of the inclined plane in such a way as to allow vertical movements of the platform with the weights. An identical instrument is to be found at the Machiavelli Lycée in Lucca.