Weight, blow and the multiplying wheel
Pulley studies with a reminder on composing the treatise
This verso pairs short mechanical propositions with pulley-and-weight diagrams (88-91) and a small red-chalk sketch at the top. Leonardo states that a weight held by a body that is struck moves toward the point of impact, and that the larger the multiplying wheel, the easier the motion of the instrument to which it is joined. He adds that the same labour arises whether the contact is small and heavy or large and light. A marginal note reminds him to write the whole text first and only later divide it with its commentary.
On this page
A weight moves toward the point that is struck
Every weight sustained by a dense body that receives a blow moves against the place that is struck. Leonardo pairs this with the rule that the larger the multiplying wheel, the easier the motion of the instrument it is joined to.
Small-and-heavy versus large-and-light contact
The labour found in the motion made by a small, heavy contact equals that of a large, light contact. The proposition weighs one form of contact against another as equivalent in effort.
Pulleys loaded with weights 8 and 4
Several pulley diagrams carry the load values 8 and 4, including a compound pulley block sketched at the lower left. They illustrate the propositions on the multiplying wheel and on light versus heavy contact.
Reminder on composing then dividing the text
A note to self instructs him to write the whole text together first and only afterward divide it with its commentary. It is a working memorandum about the structure of his own treatise.