Finding the weight positions without knowing the fulcrum
The triangular-balance rule stated for the example weights 2, 4, 1
Leonardo states his aim: to find the positions of three weights on the triangular balance without knowing its pole (fulcrum) or the spacing of the perpendiculars, needing only the differences among the given weights. Taking the example 2, 4, 1, he sets out the full arithmetic rule — subtract the smaller from the larger, divide the remainder into parts for each arm, then multiply weight by arm-division to fix each counterweight and its proportional distance from the pole. The page is entirely mirror-script text with no diagram.
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Positioning three weights without the pole or perpendiculars
Leonardo seeks the sites of the three weights of the triangular balance without knowing the pole of the balance or the spaces of the perpendiculars, asking only for the differences among the three given weights. The greatest weight multiplied by its arm-divisions becomes the counterweight, fixing each weight's proportional distance from the pole.
Subtract, divide and multiply to build each arm
With weights 2, 4, 1, subtract the smaller from the larger and from the remainder compose the divisions of the middle weight's arm; then subtract the smaller from the middle and compose the greatest weight's arm in like parts. Multiply the greatest weight by its arm-divisions to obtain the counterweight sum, and take the remainder of the middle weight as counterweight of the smaller.