| This apparatus for demonstrating the resolution of forces
is in the collection of Yale University. It was made by Deleuil of Paris,
and is described in the 1865 catalogue as "Plan vertical plu le corps parcourt
la diagonale d'un carré s'élevant par un movement composé
... 33 francs."
The black and white picture below shows how the cord is
pulled to one side to operate the device. The cord passes across the top
of the apparatus to the pulley on the right, and is tied to the pulley
in the middle. It then doubles back and passes downward over the middle
pulley and connects to the body. Pulling the cord to the left causes the
ball to move diagonally upward.