No machine multiplies power: agent and patient weights
Four 'Motion' theorems on equal power and inverse velocities
This recto is largely text: four propositions, each headed 'Motion', on the conservation of work in machines that lift weights. Leonardo declares that the infinite varieties of weight-pulling instruments are all of equal power in equal motions and weights, and that the velocities of the opposing motions stand in the same proportion as their agent and patient weights. Two small balance diagrams (marked 76 and 77) and a cone-like sketch accompany the argument. A marginal note refers the reader to figures numbered 72 on the following verso.
On this page
All weight-pulling instruments have equal power
The infinite varieties of instruments made for pulling weights are all of equal power in equal motions and in acting and receiving (agent and patient) weights. Motions become easier and quicker only as the proportion of acting to patient weight exceeds that of the corresponding motions.
Velocities in the same proportion as the weights
It is impossible to make agent and patient motions bearing to one another the same proportion the agent weights bear to the patient weights. The velocities of the contrary motions instead stand among themselves as their agent and patient motion.
Balance diagrams weighted 8 against 2
Small lever-and-balance figures at the left, marked 76 and 77, carry the load values that ground the proportional argument. They show the opposed weights whose motions the theorems compare.
Cross-reference to the figures marked 72
A marginal note observes that the figures belonging with this proportion stand behind it, pointing the reader to the diagrams marked 72 at the top of the following verso. It is a working cross-reference within the treatise.