Counterweight experiment on the best projectile form
A weight hung from a cord over five pulleys, and a plan to test spherical and feathered bodies
At the top of the page a weight hangs from a loop of cord running around five pulleys set in a quincunx, the apparatus for a projectile experiment. Under the heading 'Experiment,' Leonardo lays out a test with a given counterweight and a given fall, varying the weight and shape of the mobile body to find which spherical body is driven farthest from its motor. Once that weight is found he means to vary its length and add feathers, as with arrows.
On this page
Finding the body driven farthest by a fixed counterweight
The experiment is to be run with a given counterweight and a given fall, varying the weights and shapes of the mobile object. Leonardo wants first to determine which spherical body is driven farther from its motor than any other. Having found that weight, he will then test by varying its length and fitting feathers, as is done for arrows.
Weight on a five-pulley cord loop
The sketch shows a weight suspended from a loop of cord that passes around five pulleys arranged quincuncially, the mechanism by which a falling counterweight would drive the test body. It provides the 'given fall' of the counterweight called for in the experiment.