Moving a Pulley About Its Pole vs. With Its Pole
A double pulley diagram proving two lever arrangements are of equal power
At the foot of the sheet two small circular pulley diagrams accompany a note on levers, labelled with the points m, a, n, p and o. Leonardo argues that moving one and the same pulley about its pole takes as much effort as moving it together with its pole, invoking the principle that all equal levers moving equal counter-levers are of equal power. The upper half of the page bears a further block of red-chalk text that the bundle does not transcribe. The diagrams are lightly drawn and only partly legible.
On this page
Double pulley diagram lettered m, a, n, p, o
Two circular pulley wheels are drawn side by side, each with a hanging weight, their key points marked m, a, n and p, o. They contrast a wheel turning about a fixed pole with one turning together with its pole.
Equal levers moving equal counter-levers are of equal power
Leonardo proves that lever m-a, triple to its counter-lever n-a on the wheel that moves with its pole, is worth as much as lever p-o, triple to its counter-lever n-o on the wheel that turns about the immovable pole. The two arrangements are therefore of equal power.