The greatest ease of motion: friction and the wheel on its axle
A quarter of a dragged weight resists the mover; the wheel-to-axle proportion
Headed 'the greatest ease of motion', the sheet gathers several mechanical propositions. One shows a heavy block dragged across a plane and states that, of every weight subject to friction, a quarter of its heaviness is what burdens the mover. Another figures a wheel on its axle (pole), with the hub and hanging weights labelled a, b, c, and gives a rule relating the proportion of axle-radius to wheel-radius to the power needed to move a quarter of the wheel's weight.
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Friction: a quarter of the weight resists the mover
A heavy block is dragged over a flat plane. Leonardo states that of every weight subject to friction, the fourth part of its heaviness is what gives effort to its mover.
The wheel and its axle (pole)
A wheel with its hub a and hanging weights b, c is used to show that whatever proportion the semidiameter of the pole bears to the semidiameter of its wheel, the same proportion holds between a quarter of the wheel's weight and the power that moves it.